Impacts of indoor environmental quality on occupants environmental comfort: a post occupancy evaluation study

PDF

Download

Open document

Flip pages

Download a page range

Download transcript

Copy asset link

Request this asset

Request accessible transcript

Transcript (if available)

Content 1

IMPACTS OF INDOOR ENVIRONMENTAL QUALITY ON OCCUPANTS
ENVIRONMENTAL COMFORT: A Post Occupancy Evaluation Study
By
Varshini Raman

Committee:
Chair: Joon-Ho Choi
Email: joonhoch@usc.edu

Kyle Konis
Email: kkonis@usc.edu

Douglas Noble
Email: dnoble@usc.edu

A Thesis Presented to the
FACULTY OF THE SCHOOL OF ARCHITECTURE
UNIVERSITY OF SOUTHERN CALIFORNIA In Partial Fulfillment of the
Requirements for the Degree
MASTER OF BUILDING SCIENCE
August 2015

Copyright 2015 Varshini Raman
2

Acknowledgements

I would first like to thank Prof. Joon Ho Choi. Being my committee chair he was extremely
supportive and gave me valuable guidance at every step during my research project. He also has
encouraged me to a great extent to develop my interest in writing journals and papers. I feel
extremely privileged to have him as a mentor and part of my committee.

I would also like to thank Prof Kyle Konis, my committee member. I was able to structure and
correct my thesis work because of his in-depth feedback.

Prof. Douglas Noble, He has been a source of immense support and encouragement to complete
my project. The constant push he gave me when I lost my focus helped me finish this project.
I’m very thankful to him in deed.

I would also like to acknowledge the USC facility management services (FMS) and all the
building occupants of buildings where the research was carried out and the survey participants
who provided me with their time and effort needed for my research work. I would also like to
thank my fellow students who helped me measure IEQ data.

Lastly, If not for such a supportive and encouraging family it would have not been possible for
me to complete my research project. My husband, parents and my sister have helped me to a
great extent by all means to carryout my research thesis project successfully.
3

Table of contents

Chapter 1: Introduction to the study ........................................................................................ 14
Key Words ........................................................................................................ 17
1.1 Why carry out a POE ................................................................................... 18
1.2.1 Advantages of Post Occupancy Evaluation (POE) ............................. 20
1.2.2 Disadvantages of Post Occupancy Evaluation (POE) ........................ 21
1.3 Existing POE studies and tools .................................................................... 21
1.4 Relationship between POE and Green building standards .......................... 24

Chapter 2. The impact of façade designs on IEQ ................................................................... 26
2.1 Building envelope Attributes ........................................................................ 27
2.1 .1. Orientation ........................................................................................ 27
2.1.2 Window wall Ratio ............................................................................. 28
2.1.3 Glazing Properties ............................................................................... 29
2.1.4 Shading Devices .................................................................................. 30
2.1.5 Facade Materials ................................................................................. 33
2.2 Building influence and physiological effects ................................................ 34
2.3 Indoor Environmental Attributes .................................................................. 36
2.3.1 Thermal comfort ................................................................................ 36
2.3.2 Acoustical comfort ............................................................................. 36
2.3.3 Visual comfort ................................................................................... 38
2.3.4 Air Quality and comfort ..................................................................... 39
2.3.5 spatial quality and comfort ................................................................. 39

Chapter 3: Introduction to USC Campus Buildings ................................................................ 40
3.1 Site, location and other Characteristics ......................................................... 41
3.2 California Climate Zone 9 ............................................................................ 42
3.2.1 Weather & Climate ............................................................................. 42

Chapter 4: Research Background and Methodology ............................................................... 43
4.1 Research goals ............................................................................................. 44
4.1.2 Research Objectives of the Study: ....................................................... 44
4.2 Background Research ................................................................................... 45
4.3 Groundwork Research .................................................................................. 46
4.4 Categorizing USC campus buildings ............................................................ 46
4.5 Research Methodology ................................................................................. 47
4.5.1 chosen buildings to carry out the POE study were: ............................ 48
4.5.2 Hand held Devices used ...................................................................... 53
4.6 Modified COPE Environmental Satisfaction Questionnaire ........................ 62

4

Chapter 5: Indoor Environmental Quality Research of the building: Data collected .......... 68
5.1 Data Acquisition System (DAS) ................................................................. 68
5 .1 1 Hand held devices measurements: ................................................... 68
5.1.2 Air velocity sensor and its measurement: ......................................... 69
5.1.3 Air temperature and its measurement: .............................................. 70
5.1.4 Indoors Air temperatures .................................................................. 71
5.1.5 Floor surface Temperature ................................................................ 71
5.1.6 Radiant temperature asymmetry: ...................................................... 72
5.1.7 CO2 sensors measurement ................................................................ 73
5.1.8 Lighting Quality ............................................................................... 74
5.1.8.1-Worksurface-lux ................................................................. 74
5.1.8.2 Reading or keyboard work surface ...................................... 76
5.1.8.3 SCREEN LUX ..................................................................... 77
5.1.9 Acoustic component ......................................................................... 78
5.2 E-BOT devices measurements: ...................................................................... 79
5.2.1 The EBot Measurements ..................................................................... 79
5.3 Environmental Quality analysis survey questionnaire results ....................... 81

Chapter 6: Analysis of Data (Discussion) .......................................................................... 110
6.1 Occupant feedback Survey data vs. Measured Data ................................. 110
6.2 Occupant feedback Surveydata vs. Occupant feedback Survey ............... 124
6.2.1 Gender wise analysis: .................................................................... 124
6.2.2 Age wise analysis ........................................................................... 131
6.2.3 Lighting and Glare: ........................................................................ 136
6.2.4 Occupants comfort with the office setting and Privacy levels: ...... 139
6.2.5 Indoor Environmental quality Vs. Environmental factors and
occupant demographics. .................................................................. 146
6.2.6 STEP WISE REGRESSION FOR IEQ satisfaction level and
all other questions: .......................................................................... 154
6.3 Occupant feedback Survey vs. Physical setting ........................................ 162

Chapter 7: Conclusion and Future Work ............................................................................... 174
7.1 Conclusion and Findings: ............................................................................. 174
7.1.2 Environmental Quality analysis survey questionnaire findings ............ 176
Demographic data ..................................................................................... 177
7.1.3 Findings using MINITAB Express Analysis Software: ........................ 179
7.1.3.1 Occupant feedback Survey data vs. measured data using
hand held sensors significant findings: ...................................... 180
7.1.3.2 Occupant feedback Survey data vs. Occupant feedback Survey
significant findings ..................................................................... 181
7.1.3.3 Occupant feedback Survey vs. Physical setting
significant Findings ..................................................................... 185

Bibliography………………………………………………………………………………...187
5

List of figures:
Figure 1 Post-occupancy Evaluation by Preiser, Rabinowitz and White, 1988, p. 54. ........... 19
Figure 2 WINDOW TO WALL RATIOS (BCA2010) .......................................................... 29
Figure 3 usc site (usc.edu) ....................................................................................................... 42
Figure 4 California building climate zone map (California Energy Commission, 2010) ........ 42
Figure 5 Temperature for California Climate Zone 9, ............................................................ 43
Figure 6 Prevailing wind speed & direction for California Climate Zone 9 ........................... 43
Figure 7 Waite Philips Hall. .................................................................................................... 48
Figure 8 Allan Hancock foundations ....................................................................................... 48
Figure 9 Vivan Hall Of Engineering ....................................................................................... 48
Figure 10 Powell Hall of Engineering ..................................................................................... 48
Figure 11 Popovich Hall ......................................................................................................... 49
Figure 12 Seaver Science Library ............................................................................................ 49
Figure 13 Hoffman Hall ........................................................................................................... 49
Figure 14 Research methodology flow chart ........................................................................... 50
Figure 15 Digital light meter .................................................................................................... 53
Figure 16 Integrating sound level meters ................................................................................. 54
Figure 17 Infrared thermometers ............................................................................................. 55
Figure 18 Air velocity sensor ................................................................................................... 56
Figure 19 CO2 sensors ............................................................................................................. 57
Figure 20 Images obtained by fish eye lenses ......................................................................... 58
Figure 21 HDR camera ............................................................................................................ 58
Figure 22 EBOT automatic measurement cart ......................................................................... 60
Figure 23 LAB view screenshot .............................................................................................. 61
Figure 24 CITI Completion Report .......................................................................................... 64
Figure 25 satisfaction survey for occupants page 1 ................................................................. 65
Figure 26 satisfaction survey for occupants page 2 ................................................................. 66
Figure 27 satisfaction survey for occupants page 3 ................................................................. 67
Figure 28 air velocity measurements at 1m ............................................................................. 69
Figure 29 air velocity measurements at 1.1 m ......................................................................... 70
Figure 30 indoor air temperature measurements ..................................................................... 71
Figure 31 Floor surface temperature measurements ................................................................ 71
Figure 32 radiant temperature asymmetry measurements for a cool wall ............................... 72
Figure 33 radiant temperature asymmetry measurements for a warm ceiling ......................... 72
Figure 34 carbon di oxide levels measurements ...................................................................... 73
Figure 35 primary work surface lux measurements ................................................................. 74
Figure 36 Reading or keyboard work surface lux measurements ............................................ 76
Figure 37 Measured screen surface lux, ME ........................................................................... 77
Figure 38 the calculated UGR .................................................................................................. 77
Figure 39 Acoustic Db. measurements .................................................................................... 78
Figure 40 Mean radiant temperature of Ebot ........................................................................... 79
Figure 41 CO2 levels measured by EBOT .............................................................................. 80
Figure 42 work station – location core/perimeter .................................................................... 81
6

Figure 43 Questionnaire result –work experience ................................................................... 82
Figure 44 Questionnaire result-hours spent ............................................................................. 83
Figure 45 Questionnaire result-age group ................................................................................ 83
Figure 46 Questionnaire result-gender ..................................................................................... 84
Figure 47 Questionnaire result-job categories ......................................................................... 85
Figure 48 Questionnaire result-job satisfactions ...................................................................... 86
Figure 49 Questionnaire result-size of workspace ................................................................... 87
Figure 50 Questionnaire result-level of privacy ...................................................................... 88
Figure 51 Questionnaire Alter physical conditions ................................................................. 89
Figure 52 Questionnaire results Access to outside views ........................................................ 90
Figure 53 Questionnaire results distance between workstation ............................................... 91
Figure 54 Questionnaire results degree of enclosure ............................................................... 92
Figure 55 Questionnaire results current temperature level ...................................................... 93
Figure 56 Questionnaire results thermostats operability ......................................................... 94
Figure 57 Questionnaire results Air quality ............................................................................. 95
Figure 58 Questionnaire results noise from conversation ........................................................ 96
Figure 59 Questionnaire results noise from background ......................................................... 97
Figure 60 Questionnaire results- light for computer work ....................................................... 98
Figure 61 Questionnaire results- reflected light or glare ......................................................... 99
Figure 62 Questionnaire results- glare from light fixtures ..................................................... 100
Figure 63 Questionnaire results- glare from day light ........................................................... 101
Figure 64 Questionnaire results- Quality of lighting ............................................................. 102
Figure 65 Questionnaire results- building and office layout ................................................. 103
Figure 66 Questionnaire results- colors textures and surface finishes ................................... 104
Figure 67 Questionnaire results- Air movement .................................................................... 105
Figure 68 Questionnaire results- ambient temperature .......................................................... 106
Figure 69 Questionnaire results- lighting conditions ............................................................. 107
Figure 70 Questionnaire results- Acoustic condition ............................................................. 108
Figure 71 Questionnaire results- IEQ .................................................................................... 109
Figure 72 Ambient Temperature Satisfaction levels of the users vs. measured ambient
temperature ................................................................................................................... 110
Figure 73 Ambient Temperature Satisfaction levels of the users vs. measured ambient
temperature .................................................................................................................... 110
Figure 74 Ambient Temperature Satisfaction levels of the users vs. measured ambient
temperature .................................................................................................................... 111
Figure 75 Air quality Satisfaction levels of the users vs. measured CO2 levels .................. 112
Figure 76 Air quality Satisfaction levels of the users vs. measured CO2 levels ................... 112
Figure 77 Air quality Satisfaction levels of the users vs. measured CO2 levels interval plot112
Figure 78 Air movement Satisfaction levels of the users vs. measured Air velocity ........... 114
Figure 79 Air movement Satisfaction levels of the users vs. measured Air velocity ............ 114
Figure 80 Noise level Satisfaction levels of the users vs. measured Acoustic decibel .......... 115
Figure 81 Noise level Satisfaction levels of the users vs. measured Acoustic decibel .......... 115
Figure 82 Noise level Satisfaction levels of the users vs. measured Acoustic decibel .......... 116
Figure 83 Lighting (combined artificial and day light) Satisfaction levels of the users vs.
measured work area lux and Reading surface lux. ....................................................... 117
Figure 84 Lighting condition satisfaction level vs. measured work area luminance
7

level (lux), ............................................................................................................. 118
Figure 85 Lighting condition satisfaction level vs. measured work area luminance
level (lux) ............................................................................................................... 118
Figure 86 Lighting condition satisfaction level vs. reading area lux .................................... 119
Figure 87 Lighting condition satisfaction level vs. reading area lux ..................................... 119
Figure 88 Satisfaction levels of direct glare caused by light fixtures of the users vs.
measured UGR ..................................................................................................... 120
Figure 89 Satisfaction levels of direct glare caused by light fixtures of the users vs.
measured UGR ...................................................................................................... 120
Figure 90 Satisfaction levels of direct glare caused by Day light of the users vs.
measured UGR ..................................................................................................... 121
Figure 91 Satisfaction levels of direct glare caused by Day light of the users vs.
measured UGR ...................................................................................................... 121
Figure 92 Satisfaction levels of direct glare caused by Day light of the users vs.
measured UGR ...................................................................................................... 121
Figure 93 Satisfaction levels of glare from the computer screen of the users vs. measured
computer screen lux .............................................................................................. 123
Figure 94 Satisfaction levels of glare from the computer screen of the users vs. measured
computer screen lux ............................................................................................... 123
Figure 95 Satisfaction levels of indoor environment quality of the users vs. measured
CO2 levels ............................................................................................................. 124
Figure 96 Satisfaction levels of indoor environment quality of the users vs. measured
CO2 levels .............................................................................................................. 124
Figure 97 Gender of the users vs. Satisfaction levels of indoor environment quality
of the users ............................................................................................................. 125
Figure 98 Gender of the users vs. Satisfaction levels of indoor environment quality
of the users ............................................................................................................. 125
Figure 99 Gender of the users vs. Satisfaction levels of ambient temperature. .................... 127
Figure 100 Gender of the users vs. Satisfaction levels of ambient temperature. ................... 127
Figure 101 Gender of the users vs. Satisfaction levels of Acoustic conditions .................... 128
Figure 102 Gender of the users vs. Satisfaction levels of Acoustic conditions ..................... 128
Figure 103 Gender of the users vs. Satisfaction levels of Lighting conditions ..................... 129
Figure 104 Gender of the users vs. Satisfaction levels of Lighting conditions ..................... 129
Figure 105 Gender of the users vs. Satisfaction levels of Air movement conditions ………127
Figure 106 Gender of the users vs. Satisfaction levels of Air movement conditions ............ 130
Figure 107 Age of the users vs. Satisfaction levels of ambient temperature conditions … 119
Figure 108 Age of the users vs. Satisfaction levels of ambient temperature condition ......... 132
Figure 109 Age of the users vs. Satisfaction levels of lighting conditions ........................... 133
Figure 110 Age of the users vs. Satisfaction levels of lighting conditions ............................ 133
Figure 111 Age of the users vs. Satisfaction levels of acoustic conditions .......................... 134
Figure 112 Age of the users vs. Satisfaction levels of acoustic conditions ........................... 134
Figure 113 Age of the users vs. Satisfaction levels of acoustic conditions ........................... 135
Figure 114 Age of the users vs. IEQ Satisfaction levels ....................................................... 136
Figure 115 Age of the users vs. IEQ Satisfaction levels ........................................................ 136
Figure 116 Amount of light for computer based task Satisfaction levels vs. glare caused
due to computer screen Satisfaction levels .......................................................... 138
8

Figure 117 Amount of light for computer based task Satisfaction levels vs. glare caused
due to computer screen Satisfaction levels .......................................................... 138
Figure 118 light sources vs. the general lighting condition satisfaction levels of the
occupants .............................................................................................................. 139
Figure 119 Privacy level Satisfaction levels vs. general office layout Satisfaction levels …140
Figure 120 Privacy level Satisfaction levels vs. general office layout Satisfaction level ...... 140
Figure 121 Privacy level Satisfaction levels vs. general office layout Satisfaction level ...... 140
Figure 122 Privacy level Satisfaction levels vs. Acoustic satisfaction levels . ...................... 141
Figure 123 Privacy level Satisfaction levels vs. Acoustic satisfaction levels. ....................... 141
Figure 124 Distance between workstations Satisfaction levels vs. general office layout
Satisfaction levels. ............................................................................................... 142
Figure 125 Distance between workstations Satisfaction levels vs. general office layout
Satisfaction levels. ............................................................................................... 142
Figure 126 Distance between workstations Satisfaction levels vs. general office layout
Satisfaction levels. ............................................................................................... 143
Figure 127 Noise levels from people’s conversation vs. Noise from background noise (e.g.
mechanical systems) Satisfaction levels ............................................................. 144
Figure 128 Noise levels from people’s conversation vs. Noise from background noise (e.g.
mechanical systems) Satisfaction levels ............................................................. 144
Figure 129 Air movement satisfaction level vs. Indoor Air Quality .................................... 145
Figure 130 Air movement satisfaction level vs. Indoor Air Quality ..................................... 145
Figure 131 Job position vs. IEQ satisfaction levels .............................................................. 147
Figure 132 Job position vs. IEQ satisfaction levels ............................................................... 147
Figure 133 IEQ Satisfaction levels vs. Air Quality Satisfaction levels ................................. 147
Figure 134 IEQ Satisfaction levels vs. Air Quality Satisfaction levels ................................. 147
Figure 135 IEQ Satisfaction levels vs. Air Movement Satisfaction levels ........................... 149
Figure 136 IEQ Satisfaction levels vs. Air Movement Satisfaction levels ............................ 149
Figure 137 IEQ Satisfaction levels vs. Temperature Satisfaction levels .............................. 150
Figure 138 IEQ Satisfaction levels vs. Temperature Satisfaction levels ............................... 150
Figure 139 IEQ Satisfaction levels Vs. Lighting condition Satisfaction levels ..................... 151
Figure 140 IEQ Satisfaction levels Vs. Lighting condition Satisfaction levels. .................... 151
Figure 141 IEQ Satisfaction levels vs. Acoustic condition Satisfaction levels ..................... 153
Figure 142 IEQ Satisfaction levels vs. Acoustic condition Satisfaction levels ..................... 152
Figure 143 . IEQ Satisfaction levels vs. Spatial condition Satisfaction levels ...................... 153
Figure 144 . IEQ Satisfaction levels vs. Spatial condition Satisfaction levels ...................... 153
Figure 145 IEQ satisfaction levels versus Thermostat controls ............................................ 154
Figure 146 IEQ satisfaction levels versus Thermostat controls ............................................. 154
Figure 147 IEQ satisfaction levels vs. Distance between workstation ................................. 156
Figure 148 IEQ satisfaction levels vs. Distance between workstation .................................. 156
Figure 149 IEQ satisfaction levels vs. Light for computer work .......................................... 157
Figure 150 IEQ satisfaction levels vs. Light for computer work ........................................... 157
Figure 151 IEQ satisfaction levels vs Direct glare from light fixtures. ................................ 158
Figure 152 IEQ satisfaction levels vs Direct glare from light fixtures. ................................. 158
Figure 153 OVERALL IEQ versus IEQ Factors ................................................................... 159
Figure 154 IEQ versus Air quality ........................................................................................ 160
Figure 155 IEQ versus Air movement ................................................................................... 160
9

Figure 156 IEQ versus Temperature .................................................................................... 160
Figure 157 IEQ versus lighting conditions ............................................................................ 160
Figure 158 IEQ versus Acoustic conditions ......................................................................... 161
Figure 159 IEQ versus Spatial conditions ............................................................................. 161
Figure 160 Table 66 IEQ satisfaction levels vs. Workspace /work station orientation……..162
Figure 161 Table 67 IEQ satisfaction levels vs. Workspace /work station orientation ......... 162
Figure 162 Air movement satisfaction levels vs. Workspace /work station orientation ....... 163
Figure 163 Temperature satisfaction levels vs. Workspace /work station orientation .......... 164
Figure 164 Lighting satisfaction levels vs. Workspace /work station orientation ................. 164
Figure 165 Acoustical condition satisfaction levels vs. Workspace /work station orientation165
Figure 166 Air Quality satisfaction levels vs. Workspace /work station orientation ............ 166
Figure 167 Spatial condition satisfaction levels vs. Workspace /work station orientation ... 166
Figure 168 Lighting conditions Satisfaction levels of users vs. Orientation of the building..163
Figure 169 Lighting conditions Satisfaction levels of users vs. Orientation of the building . 167
Figure 170 IEQ satisfaction levels vs. orientation ................................................................. 168
Figure 171 IEQ satisfaction levels vs. orientation ................................................................. 168
Figure 172 Air movement satisfaction level versus WWR ................................................... 168
Figure 173 Temperature conditions satisfaction level versus WWR .................................... 169
Figure 174 Lighting condition satisfaction level versus WWR ............................................. 170
Figure 175 Temperature satisfaction levels vs. building façade color .................................. 171
Figure 176 Temperature satisfaction levels vs. building façade color ................................... 171
Figure 177 IEQ versus WWR ................................................................................................ 172
Figure 178 IEQ versus WWR ................................................................................................ 172
Figure 179 IEQ satisfaction levels VS VINTAGE of the building. ...................................... 173

List of tables
Table 1 Guidelines to POE ...................................................................................................... 19
Table 2 U-values for various glazing constructions (Autodesk workshop) ............................. 30
Table 3 Air Movement and Control Association International ............................................... 31
Table 4 Shading devices and their attributes BCA 2010 ......................................................... 32
Table 5 wall compositions and u values BCA 2010 ................................................................ 33
Table 6 Panero, Julius and Zelnik, Martin. Human Dimension & Interior Space, New York:
Whitney Library of Design, 1979 .................................................................................... 40
Table 7 Building details chart .................................................................................................. 51
Table 8 Questionnaire result-wok experience .......................................................................... 82
Table 9 Questionnaire result-age group ................................................................................... 83
Table 10 Questionnaire result-gender ...................................................................................... 84
Table 11 Questionnaire result-job categories .......................................................................... 85
Table 12 Questionnaire result-job satisfactions ....................................................................... 86
Table 13 Questionnaire result-size of workspace .................................................................... 87
Table 14 Questionnaire result-level of privacy ........................................................................ 88
Table 15 Questionnaire Alter physical conditions ................................................................... 89
Table 16 Questionnaire results Access to outside views ......................................................... 90
Table 17 Questionnaire results distance between workstation ................................................ 91
10

Table 18 Questionnaire results degree of enclosure ................................................................ 92
Table 19 Questionnaire results current temperature levels ...................................................... 93
Table 20 Questionnaire results thermostats operability ........................................................... 94
Table 21 Questionnaire results Air quality .............................................................................. 95
Table 22 Questionnaire results noise from conversation ......................................................... 96
Table 23 Questionnaire results noise from background .......................................................... 97
Table 24 Questionnaire results- light for computer work ........................................................ 98
Table 25 Questionnaire results- reflected light or glare ........................................................... 99
Table 26 Questionnaire results- glare from light fixtures ...................................................... 100
Table 27 Questionnaire results- glare from day light ............................................................ 101
Table 28 Questionnaire results- Quality of lighting .............................................................. 102
Table 29 Questionnaire results- building and office layout ................................................... 103
Table 30 Questionnaire results- colors textures and surface finishes .................................... 104
Table 31 Questionnaire results- Air movement ..................................................................... 105
Table 32 Questionnaire results- ambient temperature ........................................................... 106
Table 33 Questionnaire results- lighting conditions .............................................................. 107
Table 34 Questionnaire results- Acoustic condition .............................................................. 108
Table 35 Questionnaire results- IEQ ...................................................................................... 109
Table 36 Lighting condition satisfaction level vs. measured work area luminance level .... 118
Table 37 Lighting condition satisfaction level vs. reading area lux ...................................... 119
Table 38 Satisfaction levels of indoor environment quality of the users vs. measured
CO2 levels ............................................................................................................... 124
Table 39 Gender of the users vs. Satisfaction levels of indoor environment quality of
the users ................................................................................................................. 125
Table 40 Gender of the users vs. Satisfaction levels of ambient temperature. ...................... 126
Table 41 Gender of the users vs. Satisfaction levels of Acoustic conditions ........................ 128
Table 42 Gender of the users vs. Satisfaction levels of Lighting conditions ......................... 129
Table 43 Gender of the users vs. Satisfaction levels of Air movement conditions ............... 130
Table 44 Age of the users vs. Satisfaction levels of ambient temperature conditions. .......... 132
Table 45 Age of the users vs. Satisfaction levels of lighting conditions ............................... 133
Table 46 Age of the users vs. Satisfaction levels of acoustic conditions .............................. 135
Table 47 Age of the users vs. IEQ Satisfaction levels ........................................................... 136
Table 48 Amount of light for computer-based task Satisfaction levels vs. glare caused
due to computer screen Satisfaction levels ............................................................. 138
Table 49 Privacy level Satisfaction levels vs. general office layout Satisfaction levels ....... 140
Table 50 Privacy level Satisfaction levels vs. Acoustic satisfaction level ............................ 141
Table 51 Distance between workstations Satisfaction levels vs. general office
layout Satisfaction levels ........................................................................................ 143
Table 52 Noise levels from people’s conversation vs. Noise from background noise (e.g.
mechanical systems) Satisfaction levels ........................................................................ 144
Table 53 Air movement satisfaction level vs. Indoor Air Quality ......................................... 145
Table 54 IEQ Satisfaction levels vs. Air Quality Satisfaction levels .................................... 148
Table 55 IEQ Satisfaction levels vs. Air Movement Satisfaction levels ............................... 149
Table 56 IEQ Satisfaction levels vs. Temperature Satisfaction levels .................................. 150
Table 57 IEQ Satisfaction levels Vs. Lighting condition Satisfaction levels. ....................... 151
Table 58 IEQ Satisfaction levels vs. Acoustic condition Satisfaction levels ........................ 152
11

Table 59. IEQ Satisfaction levels vs. Spatial condition Satisfaction levels ........................... 153
Table 60 IEQ satisfaction levels versus Thermostat controls ................................................ 154
Table 61 STEP WISE REGRESSION FOR IEQ satisfaction level and all other questions . 155
Table 62 IEQ satisfaction levels vs. Distance between workstation ..................................... 156
Table 63 IEQ satisfaction levels vs. Light for computer work .............................................. 157
Table 64 IEQ satisfaction levels vs Direct glare from light fixtures. .................................... 158
Table 65 OVERALL IEQ versus IEQ Factors ...................................................................... 159
Table 66 IEQ satisfaction levels vs. Workspace /work station orientation ........................... 162
Table 67 IEQ satisfaction levels vs. Workspace /work station orientation ........................... 162
Table 68 Air movement satisfaction level versus WWR ....................................................... 169
Table 69 Temperature conditions satisfaction level versus WWR ....................................... 169
Table 70 Lighting condition satisfaction level versus WWR ................................................ 170
Table 71 Temperature satisfaction levels vs. building façade color ...................................... 171
Table 72 IEQ versus WWR ................................................................................................... 172

12

Abstract

A research methodology applying Post Occupancy Evaluation (POE) as a platform that
systematically studies and focuses on indoor environmental quality of an occupied building may
help understand and provide lessons to improve their current conditions and also provide
guidance to future building designs. In spite of significant design efforts for enhancing building
indoor environmental quality (IEQ) conditions, there have been many complaints reported from
modern work environments, such as thermal discomfort, glare, and poor air/acoustic condition
perceived in a workplace. It may be because of current guidelines developed without much
knowledge about modern technology-intensive work environment, which may be different from
the condition assumed in the current standards or guidelines. A comprehensive post-occupancy
evaluation studies can help understand the current changes that are required in order to improve
occupant environmental satisfactions and IEQ conditions by investigating the relationships
between building design/ system features, occupants’ physiological characteristics, and their
ambient IEQ conditions.
New buildings are required to meet increasingly demanding standards with respect to occupant
comfort, cost effectiveness and sustainability, while still allowing the designer to aesthetic and
design freedom. And this could be achieved through understanding historical and futuristic
approaches of building design and user satisfaction. Keeping in mind sustainability is not only
restricted to energy conservation and also extends itself occupant comfort, IEQ conditions and
user feedbacks on IEQ becomes most important criteria in a buildings sustainable design, one
has to implement POE in building process and maintenance.
13

Hypothesis

A comprehensive POE study can help understand some of the changes that could have
significant impacts on improving occupant satisfaction and IEQ conditions. The existing IEQ
conditions does influence human senses of comfort coming from interrelated physical and
mental health, and their satisfaction levels of the present IEQ conditions in their work place.
The intention of this study is to analyze the relationship between the IEQ components of the
building and the impacts caused on occupant satisfaction levels and also understand that IEQ
plays a vital role in design process and also influences user satisfaction in a great level.

14

Chapter 1: Introduction to the study

IEQ refers to the entire environmental factors and its quality, which majorly affects the health
and well being of the occupants; the factors include daylight and views (visual comfort),
acoustic comfort, air quality (IAQ), thermal comfort and spatial comfort and many others. The
Indoor Environmental Quality of a building or work environment is based not only on the
environment of the space, but also is connected to the correlation between the building design
and the microclimate.

IEQ must be controlled and managed according to the IEQ standards namely (ASHRAE, CIBSE,
IESNA, CAtitle24). But that alone would not be enough, since the guidelines developed for work
environments do not cater to the nature of todays work environments that keep changing. Todays
work atmosphere involves more computer intensive activities than desk based activities, A
flexible, collaborative workspace could improve productivity and increase employee satisfaction
while reducing real estate space and costs by increasing user density (Heerwagen, 2010)
15

POE studies can help understand the changes that are required in order to improve occupant
satisfaction and improving the IEQ. Hence the occupants require an environment that supports
all kind of functional activities that takes place in todays modern work cultures, at the same time
not causing any kind of design drawback or user discomfort. The Indoor environment quality of
a space does cause significant effects on the occupants of the space when ably or badly
managed. For example the air quality of a space causes definite impact on a building occupant a
Routine inspection and maintenance (which is a part of a buildings POE process) of such HVAC
system is an effective way to maintain good air quality. POE studies can also help understand
the changes that are required in order to improve occupant satisfaction and IEQ.

There
are
studies
that
show
that
worker
productivity
is
increased
due
to
a
controlled
and

monitored
IEQ
environment
(Singh,
1996).
Few
Studies
also
show
that
worker

performance
has
increased
with
better
lighting
conditions.
It
also
noted
indicate
that
small

(few
°C)
differences
in
temperatures
can
influence
workers’
speed
or
accuracy
by
2%
to

20%
in
tasks
such
as
typewriting,
learning
performance,
reading
speed,
multiplication

speed,
and
word
memory.
(Fisk,
W.
ASHRAE
Journal
2002).
When
provided
with
ideal

working
conditions
a
worker
can
perform
more
ideally
without
much
stress.
That
way
the

IEQ
conditions
directly
affects
the
occupants
and
their
performance
or
productivity
levels

Indoor
environmental
quality
(IEQ)
affects
occupant
comfort,
health,
and
productivity,
and

has
a
significant
impact
on
organizational
performance
(Loftness, V. V. Hartkopf, J. Choi,
and M. Snyder. 2006)

16

Improving and controlling the IEQ according to the standards would reduce illness and bring in
positive impact on the occupant. Though every designer takes much effort to elevate and
enhance the indoor environmental quality (IEQ) and conditions of the occupant, yet in the
current modern work environment where the occupant feels discomfort and is dissatisfied with
the space. Buildings perceived to have poor indoor air quality have noticeably lower overall
occupant satisfaction ratings, while buildings perceived to have good indoor air quality have
higher overall satisfaction ratings. When a building’s lighting is perceived as comfortable (e.g.
low glare, reflections, contrast) there is a positive improvement in occupant overall workspace
satisfaction, while visual discomfort exerts the opposite effect on overall satisfaction rating (Kim
J. and de Dear R. 2012)
Discomforts perceived by an occupant at a work environment:
• Poor Thermal conditions
• Poor Lighting conditions (glare)
• Poor Air and Acoustic conditions (privacy)
• Poor Spatial conditions (layout)

These could be due to the reason that the design guidelines and design were developed without
much knowledge about the current work culture and environment that involves modern
technologies and is mostly computer or technology intensive work.
The computer-based task requires a modified workplace layout that helps occupants do their
tasks without much discrepancy caused by lighting and thermal conditions at their work place.
Hence this study will focus on the understanding of IEQ satisfaction levels of occupants.

17

Key words
1.Occupant satisfaction/comfort
Occupant comfort is at most important attribute of building design, since the building is
designed for its end users/occupants. Occupant comfort refers to the satisfaction levels of the
people who use the building; it not only includes the efficiency of the building but also safety
and a health of its users, thereby helping them to accomplish their task.

2.Post-occupancy evaluation
Post-occupancy evaluation (POE) is the process of evaluating buildings in a systematic and
rigorous manner after they have been built and occupied for some time. (Preiser, 1999)

3.Environmental standards
The environmental quality standard can be defined as value or measure of limit for disturbances
to the condition of an environment or the maximum permissible levels of concentration of
potential hazardous elements in an environment, this can also be referred to as ambient
concentration of pollutants /wastes that determines the allowable levels of degradation to the
environment. (OECD, 1997)

18

1.1 Why carry out a POE
POE studies of similar building types can help in striking a balance between creative design of
the building and the utility function of the building. This is achieved by bringing in the aspect of
user feedback or occupant satisfaction as well as the actual functioning of the building which
constitutes its utility factor and the physical characteristic or the aesthetic components of the
building and the ways these interact.

The goal of carrying out a POE study is to significantly improve the comfort levels of the
occupants and to maintain the HVAC systems for better indoor conditions and also to cut down
cost. Occupant’s comfort level comprises of indoor lighting, acoustical, thermal and air quality.
The objective also includes understanding the occupant’s perspective about the building and its
performance. Building performance is also a key factor that should be taken into account in an
evaluation process (Preiser, 1995). Information that is collected by carrying out a POE provides
information for improvement of the particular building and also will be useful for other POE
studies, to compare and analyze the findings.

POE helps not only in obtaining short-term benefits to identify the issues in the building but also
helps to think of recommendations to improve the IEQ and to provide better comfort for the
occupants. The long-term benefits include aim at the development of databases and the update,
upgrade and generation of planning and design protocols and paradigms (Preiser and Vischer,
2005).

19

“Post-occupancy evaluations in architecture are concerned with social and behavioral issues as
opposed to aesthetic issues” (Wener, 1989). This explains to us that occupant comfort needs is at
most important rather than the actual building performance. The variables have to be tested and
evaluated accordingly (variables=IEQ factors) in order to understand better and provide solution.

Figure 1 Post-occupancy Evaluation by Preiser, Rabinowitz and White, 1988, p. 54.

Table 1 Guidelines to POE

14
Guide to Post Occupancy Evaluation
15
Guide to Post Occupancy Evaluation
Section 4: Identifying Approach to Use
4.1: Deciding which approach to use
There are two principal choices, either develop your own approach using a range of existing evaluation
techniques (Tool 3) or use an established method.
A bespoke solution may be useful for specific situations for example, where the intention is to analyse
specific issues. While this approach can enable benchmarking across an institutions’ own estate, the
downside is that expertise may be needed to interpret more complex findings or to carry out some types
of evaluation.
Table h: Advantages and disadvantages of creating your own POE methodology or using an
established method
Existing Methods
Advantages Disadvantages
• Already tested
• Ready to use
• Backed up by rigorous research
• May offer benchmarking with other
organisations in Higher Education sector
• Expertise available to administer
• May be able to license use of method
• May be a significant cost
• May not be suitable for specific situations
• Ownership of the data may not be yours
• Cost of expertise to back up
Bespoke Methods
Advantages Disadvantages
• Tailor to suit specific needs
• May cost less than established method
• Under your own control
• Time needed to set up
• Expertise needed
• May cost more than established methods
4.2: Existing methods
A summary of the established methodologies available are given in Table i.
4.3 Bespoke approaches
Table j summarises the suitability of techniques for each review stage. This chart can be used by those who
wish to put together their own POE. Clearly it is possible to use most of the techniques at every stage, but
this guide aims to indicate which are likely to be more or less useful in the context of busy organisations
needing to gather enough quality data that will provide useful information which the organisation can
then act upon. There is a danger of gathering a lot of data which may be valuable but leaves a significant
data handling problem, and may in the end not be analysed because of the magnitude of the task. The
usefulness of the technique is based on a balance of useful information gathered for the effort required.
When deciding which techniques to use it is helpful to consider how different techniques can be combined.
For example combining a questionnaire with a focus group or workshop will enable different levels of
information to be gathered with the workshop or group being used to tease out some of the results from the
questionnaire.
It is important to make the study manageable by erring on the side of gathering less data, but focusing
on the quality of it. So rather than use every technique for each area of the review select those which will
best meet your purpose.
Table i: Established POE methods available
Method Format/
techniques used
Focus How long does
it take?
When is/can it be used? Reference
De Montfort method Forum
Walk-through of the
buildings
Broadly covers the
process review and
functional performance
1 day generally A year after occupation www.architecture.com
click on client forums
CIC DQIs
(Design Quality
Indicators)
Questionnaire Covers functionality,
building quality and
impact
Questionnaire
completion is online
– takes about 20-30
minutes. Analysis is
immediate
At design stage and after
completion
www.dqi.org.uk
Overall Liking Score Questionnaire:
– hard copy
– web based
7 point scale
Occupant survey
Sectors include
educational
Diagnostic tool
10 minutes for each
occupant
About 12 months after
occupation
www.absconsulting.uk.com
PROBE Questionnaire
Focus groups
Visual surveys
Energy assessment
Env. Performance of
systems
User satisfaction /
occupant survey
- Productivity
Systems performance
Benchmarks developed
Overall process
varies time needed
2 days (over two
months?)
One-person month
Any time but PROBE
team recommend
earliest at 12 months
www.usablebuildings.co.uk
BUS Occupant
survey
Building walk-throughs
Questionnaire backed
up by Focus groups
Occupant satisfaction
Productivity
10 – 15 mins
to complete
questionnaire
On its own or in
conjunction with
other methods
Anytime but often after
12 months
www.usablebuildings.co.uk
Energy Assessment
and Reporting
Methodology
Energy use survey
Data collection e.g.
from energy bills
Energy use and
potential savings
Full assessment up to
one-person week
Once building
is completed
On its own or in
conjunction with other
methods e.g. PROBE
www.cibse.org
Learning from
Experience
Facilitated group
discussions or interviews
Team learning from its
experience.
Ranges from single
seminar to continuous
evaluation
Can be used before,
during and after project
as ‘Foresight, Insight and
hindsight’ reviews
20

1.2.1 Advantages of post occupancy evaluation (POE)
POE helps in identifying the problems that exist in the buildings; it further helps in investigating
these problems or issues to provide a better space in terms of occupant comfort and energy
consumption. This also helps in understanding the various attributes of the building under
different conditions such as building envelopes Facade system, climatic conditions, HVAC or
Mechanical systems, occupancy profile etc. The acquired information helps in improving the
conditions of a building and helps it to perform better. POE not only helps in identifying the
problem but also helps in providing insight to the future buildings that might imbibe the findings
in their design and developments. POE also helps in the renovation of existing buildings; by
understanding the problem encountered by the occupants, the building can be modified and
adjusted to meet the changing trends and practices of the occupants of the building and
improving its standards. POE helps identify problem areas that lead to reduced building
operating cost and maintenance.
The codes and standards can be renewed or changed and modified by applying the lessons learnt
by the means of a POE study. The designers would be more interested in finding out the user
feed back since the buildings performance is judged not only with utility bills but also how the
building users understand how the building works for them. (Post Occupancy Evaluation.com,
2011)

21

1.2.2 Disadvantages of post occupancy evaluation (POE)

POE is considered and accepted as an important tool or element, which facilitates the
understanding of the relevant problems of a building. It, however, is observed as a process that
has some drawbacks. POE as a discipline has been having trouble being integrated itself as part
of curriculum in academic institution and is only prevailing in very few British schools of
architecture. The most common observation during its early stages of adoption of the POE
methods was that they were considered highly expensive (CABE, 2011). The expense was
primarily due to a vague direction and undefined implementation of methodologies. The
investigated problem once rooted to the source was not an easy fact for the designers or
constructors involved in the building design to accept or to take responsibility for. The building
owners did not have much awareness of the role of a POE in the energy consumption of the
building. The occupant’s satisfaction levels were not considered as a high priority till very
recently. The architects and designers were hesitant to adopt such methodologies since they were
bothered to face legal issues that create higher liability. Post-Occupancy Evaluation and its
Implications in Architectural Education are very less. (CABE, 2011)
1.3 Existing POE studies and tools
Since buildings are comprised of complex systems, their interaction with the occupants adds to
its complexity by bringing in potential malfunction. A multi level POE approach that checks and
tests the current conditions of the building and also attempts to study the physiological and
physiological aspects, since all these issues together will influence the energy consumed by the
building and well being of the occupant.
22

PROBE and CBE
The Center for the Built Environment at UC Berkeley produced a survey tool (protocol) called
the PROBE (Post-Occupancy Review of Buildings and their Engineering). This tool was
developed nearly 20 years ago and has been applied on about one thousand building till now.
The probe protocol is modified and now it works with the occupants taking 4-10 minutes to
complete a questionnaire. All surveys are recorded on paper. A 7-point scale is used for
responses to questions. Responses are tabulated using an Excel spreadsheet.

Apart from developing the POE protocol The CBE has been carrying out a survey to evaluate the
IEQ in office buildings. The IEQ was categorized into nine divisions and occupants were
surveyed to analyze occupant satisfaction, in an anonymous reporting and invite-style web-based
questionnaire

A paper-based survey was designed for the Buildings-In-Use program, which comprises about
30 questions (Vischer, 2005).

The NIOSH (National Institute of Occupational Safety) has conducted various research projects
in order to evaluate and investigate IEQ at various building facilities. One such project is the
Evaluation of Indoor Environmental quality at an accounting office. The NIOH along with HHE
program (health hazard programmed) conducted this study based on the concerns of the
occupants who reported concerns including headaches, chronic coughing etc. The team reviewed
consultant reports of several IEQ evaluations, observed the office space, took measurements,
23

recorded temperatures and tested for VOC in the air, collected carpet dust samples to analyze for
micro organisms. By carrying out all the required test identified the issue and provided design
recommendations to the building owners and the organization.

I BEAM is a computer based software tool, which provides interactive design guidelines for the
designing of buildings to have better internal air quality (IAQ).

The ASHRAE Guide: Best practices for design, construction and commissioning provides
guidance in addressing IEQ issues, The ASHRAE journal: How IEQ affects health and
productivity enumerates the understanding by William J. Fisk, P.E, A member of ASHRAE on
how a better IEQ would help/ enhances the worker productivity of an environment in US
buildings.

A project conducted by the NIBS (national Institute of building sciences) on Indoor environment
quality explains about the recommendations for improvement of IEQ standards especially for the
people with disabilities. Considering the fact that there are significant numbers of people who
are sensitive to chemicals, NIBS conducted surveys and provided recommendations to achieve
their goal of healthy buildings.

‘Post-occupancy evaluation of 20 office buildings as basis for future IEQ standards and
guidelines ’ by Joon-Ho Choi, Vivian Loftness, Azizan Aziz at the
University of Southern
California, and Carnegie Mellon University
with an partnership with the U.S. General Services
Administration (GSA)
24

The Center for Building Performance and Diagnostics research team at Carnegie Mellon
University (CMU) conducted a post-occupancy evaluation (POE) field studies in 20 commercial
office buildings to develop recommendations and values for updating standards and also
recommendations for a better environment that satisfies sustainability quotient and occupant
wellbeing.
‘Investigation on the impacts of different genders and ages on satisfaction with thermal
environments in office buildings’ is a paper written by the same team, this article investigates the
effects caused by the thermal conditions on the basis occupant's gender and age. The data used
for the analyses was collected from 40-sampled occupants and their work- stations on 38 floors
in 20 office buildings in the U.S. This study resulted that thermal sensitivities and satisfaction
differ with gender. Both the above studies were carried out using a systematic approach and
methodology.
1.4 Relationship between POE and green building standards
Buildings with sustainable features are not only expected to save energy but also to provide its
occupants with a good indoor environment. Three POE studies conducted in Germany
investigated green buildings referring to thermal comfort and occupant satisfaction. Although
their research targets differed, their findings were interrelated, its noted that the perception of the
respondents who were working in these green buildings their thermal comfort levels were
considerably higher than the buildings that had normally set air conditioned temperatures.
Studies show that occupants in naturally ventilated buildings perceive higher temperatures as
comfortable. But the building designers are forced to use the standards that vary from the actual
perceptions of the occupant. (Gossauer 2005; Pfaafferott et al 2007 and Wagner et al 2007).
25

Day lighting and visual comfort are fundamental features of IEQ of a building. By introducing
daylight into office spaces through operable windows and using it as a source of lighting the
energy consumption by artificial lighting can be reduced considerably. A field study carried out
in Japan between years 2002 and 2007 in nine different office buildings by questionnaires, and
surveys were conducted. The results were that installation of large windows has the advantage
that energy is saved, and visual comfort is obtained by daylight and views ( lto et al 2008)

26

Chapter 2. The impact of façade designs on IEQ

Facade is considered to be the meso-environment between the microenvironment of humans and
the external macro-environment, which plays an important part in contributing to a productive
and comfortable individual life (Wang Liping & Wong Nyuk Hien,2006). This can be interpreted
that a meso environment is the setting between the macro and microenvironment, which
influences the model in many aspects. The facade design like wise influences or causes impacts
to the buildings and its users and also the external environment.

Designing a Facade is a very important. It is a vital aspect that highly influences the IEQ of a
building. The Facade not only acts as the outer shell of the building to protect the indoor
environment, but it also facilitates its climate control. An understanding of how the envelope
interacts with the outside environment is very critical in designing energy-efficient and
comfortable buildings for the user. This is because the building envelope is the first step in
controlling the internal environment. It keeps out moisture and insulates against heat losses and
gains, while admitting useful daylight. It also influences the building performance factors such
as the thermal comfort, daylight, glare, energy efficiency, natural ventilation and noise (BCA,
2010).

27

There are several important façade design parameters. Evaluating the combination effect of
different façade design parameters could enhance indoor thermal environment and will also help
in developing a tool or methodology in achieving a well performing façade design for buildings.
The façade design parameters including orientations, window to wall ratios, and the dimensions
of shading device should be taken into account (Wang Liping & Wong Nyuk Hien,2006).
2.1 Building envelope attributes
2.1 .1. Orientation
Building orientation refers to the way a building is situated on a site and the positioning of
windows, rooflines, and other features. Building orientation and materials also facilitate
temperature moderation and natural delighting (NJGBM 2011).

Optimizing the orientation of a building helps to minimize the solar heat gains and increase the
natural ventilation. According to the positioning and orientation of the building, the glazing
should be provided where it is effective for views and/or daylight. Heat gains can be addressed
by careful façade design, which should vary as a function of the orientation. As an
environmental filter, the building façade or envelope is often the first line of defense against
undesirable external elements. This is quantified through the Envelope Thermal Transfer Value
(ETTV) for non-residential buildings. (BCA 2010)

28

2.1.2 Window wall ratio
The window to wall ratio of a building is the percentage of its facade taken up by light
transmitting glazing surfaces, including windows and translucent surfaces such as glass bricks. It
does not include glass surfaces used ornamentally or as opaque cladding, which do not provide t
ransparency to the interior. Only facade surfaces are counted in the ratio, and not roof surfaces.
(Static.space.com 2011)

Based on many published strategies for day lighting a building, it has been found that a whole
building WWR = 0.20 to 0.30 ratio of window area to wall area is preferred. An overall WWR <
0.20 does not provide enough daylight, WWR > 0.30 allows too much heat loss in winter and too
much heat gain in summer. . (Vanagas 2011)

Envelope Thermal Transfer Value (EETV) Definition:
Reducing window size means more of the outside heat is prevented from being transferred inside
because of the solid walls. The lower the WWR, the better the ETTV / RETV. Opaque
enclosures generally resist heat transfer better than glass. When the WWR goes beyond 50%,
achieving acceptable ETTV and low heat gains becomes more difficult. A WWR above 50%
would normally require high-performance glazing with very low SC, and/or heavy shading in
order to comply with ETTV. (SBRN)

29

Figure 2 WINDOW TO WALL RATIOS (BCA2010)

2.1.3 Glazing properties
The properties of the glass are very important since it controls the amount of daylight that enters
the building it also determines the quality of light, the solar heat gain along with other factors
that included visual comfort and thermal comfort.

Glass performance based on the material, coatings and construction that make up the windows
and other compositions that let the sunlight into the building can be indicated through a number
of properties. The most important are the Visible Light Transmittance (VLT), Shading
Coefficient (SC) and U-value.
30

Table 2U-values for various glazing constructions (Autodesk workshop)

2.1.4 Shading devices
The main purpose of an external shading device is reducing the direct solar gain through
windows. (AMCA) Its secondary functions would be to control views into and out of a building,
reduce solar glare, provide rain protection for opening windows, and to serve as part of a
maintenance strategy.

31

Table 3Air Movement and Control Association International

32

Table 4 Shading devices and their attributes BCA 2010

33

2.1.5 Facade materials
The façade materials include the aspect that contributes to the environmental performance of a
building. It plays a big role in reducing heat transmission. The façade material is selected on the
basis of its properties that include
Insulation: The insulating property of an opaque wall construction is indicated by the U-value.
Construction materials with low U-values help to improve insulation in all opaque areas of the
building envelope, and not just the façade.
Thermal conductivity: Some materials allow a greater heat flow than others.

Colors’: colors also affect the thermal performance of the building a white object will absorb
less heat than a blue one. Materials such as ceramics and Glass Fiber Reinforced Concrete
(GRC) in light tones can reduce the heat buildup in poorly ventilated areas. Breaks in framing
systems can also reduce direct heat flow. (BCA 2010)

Table 5wall compositions and u values BCA 2010
34

2.2 Building influence and physiological effects
“Thermal comfort, or the lack of it, is well understood to be one of the most significant
restrictors to the health and general wellbeing of the older people” (Novieto & Zhang, 2010).
Thermal conditions in a space impacts the elderly in a predominant manner. As we know the
elderly are very sensitive to the thermal conditions of the space that they use.

The building performance is a major factor that is kept in mind while designing and planning a
buildings design. More importantly the physiological effects caused by the building also must be
taken into account while designing the building. The positive and negative effects must be
analyzed and understood to create a space that caters to the needs and comforts of the building
occupants.

Prolonged occupation of any confined space can have unanticipated adverse health effects. For
example, in buildings with poor air quality and sanitation, occupants run the risk of developing
symptoms associated with Sick Building Syndrome (SBS).

Improvements made to building components have a direct bearing on human health. (Seppanen
et al. 1999 and Wargocki et al. 2000) the ventilation rate in an indoor environment is inversely
proportionate with sick building syndrome (SBS) symptoms; i.e.: increase in the ventilation rate
in a given space will result in a decrease of the of SBS.

35

An increased outdoor air supply and the replacement of filters can reduce SBS symptoms.
(Wargocki et al. 2004 and Milton et al. 2000) there is a relationship between lower levels of
outdoor air supply with increased sick leave of employees accompanied by increased rates of
IAQ complaints in the workplace.

Connection to nature through window views has been consistently stated to have a strong impact
on health and wellbeing. (Ulrich ,1984)

“Psychological determinants are those factors that are associated with the psychological needs
and concerns of the occupants. Visual privacy, acoustic privacy, and aesthetic factors are a few
important key factors for consideration. Psychological determinants directly have impact on a
person’s sense of well being in the environment. Privacy is defined as a central regulatory
human process by which people make themselves more or less accessible to others”. (USACE
Design Guide for Interiors 1997)

The occupants tend to do much lesser physical activities in todays work condition that involves
computer intensive tasks; the need to move around at work place has reduced considerably in
turn decreasing the metabolic rate of the occupants. Hence a higher thermal temperature is
required to maintain the optimum comfort level of the occupants. (ASHRAE Standard 55.).

36

2.3 Indoor environmental attributes
The indoor environmental quality related to psychology and ergonomics is always developed
with the idea of improving workforce productivity by modifying the physical environment of
workers. To achieve this goal the indoor environmental attributes need to be studied and
understood.
2.3.1 Thermal comfort
Occupant comfort for a long time has only been related to light, heat and ventilation (Brager and
de Dear, 1998) but thermal comfort of a space is a very import factor that needs to be taken into
account The lack of thermal comfort would contribute to the general health and well being of the
occupants. Thermal comfort of a space /building is difficult to determine. Occupants are
sensitive to the temperatures of the environment on the basis of Building design, changes in the
body, apparel that they are wearing and other factors. systematic research on thermal comfort
and the effect of apparel and activity upon the human heat exchange as the cause of thermal
comfort. (Fanger, 1970)

2.3.2 Acoustical comfort
Excessive indoor noise is a major issue in many buildings; a noisy atmosphere in a workspace
can have adverse effects on the stress levels and can cause and affect health and well being of
the occupants. The noise level if not controlled can have negative effects on the productivity of
the occupants and also can cause distractions for them.

37

Acoustic comfort also includes acoustic privacy, lack of proper sound blocking systems in such
buildings and a lack of acoustic absorption in open plan offices, is a growing concern. Proper
acoustical treatments are inadequate in most cases. Sound control regulations should provide
more guidance for the design of acoustical treatments for the building. Speech privacy is a major
contributor to a desirable level of communication, social interaction, and productivity in a work
environment.

38

2.3.3 Visual comfort
Lighting in a building is connected to the visual comfort of the occupant Light is an important
factor to consider when designing a building. Light is a form of energy whether it is diffused or
direct Light also produces heat when it falls on a surface hence it is strongly related to thermal
conditions of a place. The colors and luminance of our surroundings play a major role in visual
comfort. The utilization of day light to the maximum and balancing it with artificial lighting is
the key to a good design. Day lighting is often proposed as an energy conservation strategy.
However the primary obstacle in utilizing day lighting is the lack of a simple method for
predicting and visualizing light levels (Sun, R. 1986). Day lighting is often proposed as an
energy conservation strategy. But the primary obstacle in utilizing day lighting is the lack of a
simple method for predicting and visualizing light levels (Sun, R. 1986). Physiologically
sunlight is very essential to older people in the production of Vitamin D in the skin. Windows
block the UV rays necessary for human production of Vitamin D.
Visual comfort is addressed by different standards and codes based on light intensities. Each
individual relates to both quantitative properties and non-quantitative quality of light in various
different settings. The CIBSE 1994 provides quantitative standards for different tasks but not
much about qualitative qualities such as material and color that may affect the visual properties
of the space.

39

2.3.4 Air quality and comfort

Indoor
air
quality
(IAQ)
can
be
defined
as
the
air
quality
that
exist
inside
and
around
the

building.
The
IAQ
is
highly
related
to
the
health
and
comfort
levels
of
the
building

occupants.

The
variables
that
affect
IAQ
are
gases,
particulates,
air
velocity
or
air
speed

and
the
air
Temperature.
Gases
such
as
carbon
monoxide,
radon,
and
volatile
organic

compounds
may
affect
the
health
of
the
occupants
soon
after
exposure
or
years
later.

Particulates,
microbial
contaminants
(mold,
bacteria)
can
also
adversely
affect
human

health.
(Wikipedia).
The
air
speed
or
air
velocity
can
be
identified
as
a
very
important

aspect
of
air
quality
since
if
not
sufficient
or
if
high
can
cause
major
discomfort
to
the

building
users

Air
temperature
plays
a
major
role
in
indoor
environment
quality
as
the
temperature

conditions
of
a
space
influences
and
creates
high
impact
on
the
occupants
of
the
space.

2.3.5 spatial quality and comfort
Spatial
quality
plays
an
important
role
in
human
building
relation
ship.
The
interior
layout

and
its
parameter
of
the
building
affect
the
user
comfort.

The
‘building
user’
is
in
the
focus

of
microcosm
architecture,
which
considers
the
parameters
generating
comfort
and

wellbeing
of
users
(Gratia
and
Herde,
2011).

The
spatial
resolution
will
help
the
occupants
experience
a
better
environment
and
hence

can
be
more
comfortable
and
productive.

40

Especially
in
office
spaces
the
spatial
quality
should
be
very
functional
and
comfortable
to

the
occupants,
in
building
design
assessment
field
of
research,
the
‘interior
layout
design’

was
interpreted
to
‘Indoor
Environment
Quality’
(IEQ)
According
to
(Choi
2011).

Office
spaces
should
allow
for
easy
movement,
accommodating
visitors
where
necessary,

and
storage.
The
table
below
provides
some
ranges:

Application

Minimum
Requirement

Ranges*

Two
people
can
meet
in
an
office
with
a
table
or
desk

between
them
-‐
such
as
a
supervisor
and
an
employee

60-‐72"
x
90-‐
126"

152-‐183
cm
x

228-‐320
cm

A
worker
has
a
primary
desk,
and
a
secondary
surface
such

as
a
credenza

60-‐72"
x
60-‐
84"

152-‐183
cm
x

152-‐213
cm

Executive
office:
3-‐4
people
can
meet
around
a
desk

105-‐130"
x

96-‐123"

267-‐330
cm
x

244-‐313
cm

A
basic
workstation
-‐
such
as
call
center

42-‐52"
x
60-‐
72"

107-‐132
cm
x

152-‐183
cm

Table 6Panero, Julius and Zelnik, Martin. Human Dimension & Interior Space, New York: Whitney Library of Design, 1979

41

Chapter 3: Introduction to USC Campus Buildings
3.1 Site, location and other characteristics
“The campus of the University of Southern California is located primarily in the University
Park campus which is in the West Adams district of South Los Angeles, 2 miles (3.2 km)
southwest of Downtown Los Angeles. The campus' boundaries are Jefferson Boulevard on the
north and northeast, Figueroa Street on the southeast, Exposition Boulevard on the south, and
Vermont Avenue on the west “. (Wikipedia)
University of Southern California (USC) was established in 1880. The campus buildings are
predominantly of 1920s Northern Italian Renaissance Revival building style. But in the 1960s
and ‘70s there were buildings constructed that were reflective of the Modern tradition. The
campus has been having number of additional buildings constructed every year. Concrete and
brick is the most commonly used as building materials in order to maintain a sense of coherence
among the various architectural styles in this expanding campus.
University Park Campus is Located next to one of the city’s major cultural centers, Exposition
Park, USC’s 226-acre University Park campus (UPC) is very close to downtown Los Angeles
and is easily accessible by major freeways, and by Metro Expo line. (Usc.edu)

42

Figure 3:usc site (usc.edu)

3.2 California Climate Zone 9
3.2.1 Weather & climate
According to the Californian climate zone map provided by the California Energy Commission,
The campus is located in Climate Zone 9 as shown in Figure 4. Zone 9 is classified as Southern
California Inland valley and is influenced by both coastal and interior weather.

Figure 4California building climate zone map (California Energy Commission, 2010)
43

Figure 5Temperature for California Climate Zone 9, Figure 6Prevailing wind speed & direction for California Climate Zone
9
Prevailing Wind Direction; summer: NW; winter: NW
Natural Ventilation is most effective when wind speed is 5 mph or greater.

44

Chapter 4: Research Background and Methodology
4.1 Research goals
The goal of this research is to understand the impacts of IEQ on occupants’ environmental
satisfactions level and comfort conditions. To achieve that, a post occupancy evaluation process
was carried out. To proceed with the post occupancy evaluation process, background research
was conducted which separated the entire research work into three main categories.
4.1.2 Research objectives of the study:
This study aims to research ways to improve accountability in designing spaces which influence
human senses of happiness coming from interrelated physical and mental health, healing and
wellbeing.
The intention of this study is to analyze the relationship between the IEQ components of each
building and occupant satisfaction levels
Understand the IEQ variables measured and bring in comparison with the current industrial
standards such as ASHRAE, CIBSE, and IESNA, CA Title24.
Investigate the influence architectural parameters on the IEQ measurements. Restricting the
scope to external architectural parameters such as Building type (functional), Orientation,
vintage, Façade features such as Shading elements, color, WWR. Internal parameters such as
position of works stations (core or perimeter).

45

By investigating and analyzing the relationships between the buildings design, human factors,
system features it is possible to come up with solution to enhance the occupants’ physiological
characteristic conditions and also improve their ambient IEQ conditions.
4.2 Background research

In order to proceed with post occupancy energy evaluation the research process was broken
down into three main categories listed below:
Task 1
• Analyze the various buildings in the USC campus, by acquiring building details and data
from the FMS department and categorize them using the help of statistical software tool
on the basis of their spatial function.

• Measure the IEQ values in the chosen buildings using the hand sensors, environmental
cart E Bot (Environment measurement cart developed by Prof Joon Ho-Choi and team)
and simultaneously request the occupants to take part and answer the IEQ satisfaction
questionnaire.

• Analyze and study the data collected and understand the effects and causes and the role
played by internal environmental quality of the building on the occupants.

46

4.3 Groundwork research

Details and information of the campus buildings that were vital in odder to begin the study was
gathered through the Facility and Management Services department. Further to enable the
research Online resources and visual observations were made. The first step was the
accumulation of the list of campus buildings. The second step was to filter out buildings that
were under four-story height and did not have enough office spaces to conduct the study. About
30 such buildings were taken into account and information was accumulated. The information
collected included Architectural and constructional details, Functional information; occupancy
levels architectural drawings and mechanical drawings. The information regarding the building
facade / envelope was predominantly collected by visiting and observing the buildings .The
observation was from both outside as well as inside to observe external and internal features of
the building.
4.4 Categorizing USC campus buildings

The USC campus buildings are first classified according to their number of stories. Buildings
with storey height lesser than four are omitted from the study. This elimination process is done
since most of the current office buildings are mostly 4+ storey. To get a better understanding of
the qualities of office buildings, buildings with storey height four and above are taken into
consideration. An inclusion of Library building was done in order to study an open type
workstation layout.

47

At this stage the number of buildings that fell under this category were about thirty buildings.
The Architectural and constructional details about each of these buildings were collected and
listed. The collected information included
1. Storey
2. Area details
3. Construction date
4. Façade materials
5. Façade color
6. Façade system construction type
7. Architectural style
8. Type of shading device
9. Orientation
10. Function of the building
11. Window wall ratio
4.5 Research methodology

The research methodology begins with categorizing the USC campus buildings by acquiring
their building attributes and building Features. These campus buildings are grouped according to
their spatial function. Similarities and diversities in the building attributes and parameters are
identified. Seven buildings that have predominantly office spaces are chosen to carry out the
POE study. A library building is included as part of the study to begin to explore an open office
type atmosphere. The IEQ measurements and user satisfaction feedback is obtained in the
process.
48

4.5.1 chosen buildings to carry out the POE study were:

Figure 7Waite Philips Hall. Figure 8 Allan Hancock foundations

Figure 9Vivan Hall Of Engineering Figure 10Powell Hall of Engineering

49

Figure 11Popovich Hall Figure 12Seaver Science Library

Figure 13Hoffman Hall

Thermal conditions, air quality, lighting levels /visual comfort and acoustic decibel
measurements, Co2 levels are collected with the help of hand held devices. The mean radiant
temperature is calculated by automatic Environmental quality measurement cart “E-BOT” from
120 workstations in 7 of the chosen campus buildings. The study also utilizes a modified COPE
50

environmental satisfaction questionnaire, developed by National Research Council Canada. The
questionnaire consists of 30 questions on a seven-point scale, which includes five demographic
questions.

Figure 14Research methodology flow chart

51

The seven buildings that were chosen to carryout the study, their names and the obtained
building data are below in a chart format.

Table 7 Building details chart
52

The research is carried out in a simultaneous manner by collecting environmental measurement
and by distributing an occupant satisfaction questionnaire to the user of that particular
workstation. A multi-method approach is employed in order to collect all the data that is
important to investigate and decipher the comfort and satisfaction levels of the end users. The
approach adopted in this research is a strategy of data collection that incorporates IEQ
measurements using hand held devices, Spot measurements using The Environmental quality
measurement cart and information gathering through interviews and a survey questionnaire.
(Based on COPE) The post-occupancy evaluation (POE) of the chosen office building first
begins with the. Acquiring on-site measurements for IEQ conditions. The technical attributes of
the IEQ namely the Thermal, air lighting and acoustic conditions would be recorded. To carry
out the above process the following hand held devices and sensors are used and data is collected
by means of on site measurement.

53

4.5.2 Hand held devices used
Digital
light
meter

Figure 15 Digital light meter

A light meter is a device that is used to measure the amount of light. The handheld light meters
are used to precisely measure the light falling on various parts of their subjects and use suitable
lighting to produce the desired exposure levels. (Wikipedia)
OPERATION INSTRUCTIONS:
1. Once the power is set the desired range was chosen according to the background noise
observed switch to the desired range (The range button includes t 20lux, 200lux, 2000lux,
20000lux) or only 200000lux range.
2. The sensor head cover is removed.
3. The sensor head is holed steadily and once it was made sure that the light source falls
completely, I Moved away from the sensor head to avoid shadowing it.
54

The illuminance value from the display was noted down. If magnitude of lux (or fc) was not
known the RANGE button was pressed to obtain the highest range and reduce it until a
satisfactory reading was obtained, The light levels were observed in a similar manner for the
work surface lux, the screen lux and the reading surface lux.
2.Integrating sound level meter

Figure 16 Integrating sound level meters

A sound level meter or sound meter is an instrument that measures sound pressure level,
commonly used in noise pollution studies for the quantification of different kinds of noise
(Wikipedia)
OPERATING INSTRUCTIONS:
1. To test the acoustical conditions first the Measurement Range Slide was set and the switch "O
(power-off) / Lo (35-90dB) / Hi (75-130dB)". The meter has 2 sound pressure level (SPL)
measurement ranges each with a dynamic range of 55dB.The sound pressure level is indicated
and updated every one-second. Secondly the Time Weighting is set by using the Slide switch: S
(SLOW) / F (FAST) to slow since we are measuring normal conditions.
55

The time weightiness available are: S (SLOW): for normal measurements and F (FAST): for
checking average levels of fluctuating noise.The Frequency Weighting is set to A using the Slide
switch: A / C. Since A: is for general sound level measurement
3. Infrared thermometer

Figure 17. Infrared thermometers
An infrared thermometer is a thermometer, which infers temperature from a portion of the
thermal radiation sometimes called blackbody radiation (Wikipedia)
OPERATION INSTRUCTIONS:
To measure the temperature of a particular surface the measuring trigger is clicked and the
device is pointed at an object and the trigger is pulled. The distance-to-spot size ratio and field of
view is considered while doing the measurement. The laser is used for aiming at the target for
reference. The temperature reading will be updated on the LCD. The reading was noted for
Vertical and Horizontal temperature levels. The reading will automatically be held on the LCD
or 10 more seconds. After 10 seconds this thermometer will power down itself to save battery.
• DISTANCE TO SPOT RATIO (D/S)

56

You have to make sure that the detection area you want to measure is larger than the required
spot size to get a correct reading. The temperature you get is an average temperature of the
detected region. The smaller the target, the shorter distance is required for the measuring.
4. Air velocity sensor

Figure 18Air velocity sensor

This air velocity sensor or Hot wire anemometers uses a very fine wire (on the order of several
micrometers) electrically heated up to some temperature above the ambient temperature. Air
flowing past the wire has a cooling effect on the wire. As the electrical resistance of most metals
is dependent upon the temperature of the metal (tungsten is a popular choice for hot-wires), a
relationship can be obtained between the resistance of the wire and the flow speed.
(Wiki)

First the the probes plug is connected to the input socket and the Power is turned on the desired
temperature units using the degree Celsius or Fahrenheit button is selected to Celsius. And the
velocity unit is set to FT/Min using the unit button.

57

1. Utilizing the sensing head slide the sensor cover to the up position to let the air
velocity sensor become isolated from the environment
2. Push the zero button the reading value of air velocity display zero value
3. Slide the sensor cover to the down position to let air velocity sensor contact the air
4. During measurement pushing the data hold button to hold the values
5. CO2 sensor

Figure 19 CO2 sensors

OPERATING INSTRUCTIONS:
1.Press the Power Button and a 2 second delay will occur before the display becomes visible.10
seconds will elapse before displaying current CO2 readings
2.WARM-UP will display for approximately 1 minute. During this time, adjustments cannot be
made to the sensor. After warm-up the sensor will stabilize and display current conditions.
58

Display Features
CO2 Readings (Upper Display) - Remain visible at all times.
Temperature and Ventilation Rates (Lower Display)
The Up/Down arrows allow you to toggle through the Temperature and Ventilation modes.
When pressing the up arrow, the display will go through the following sequence:
Temp°C > Temp°F > Vent Rate l/p/s > Vent Rate cfm/p > Blank
6. HDR camera fish eye lens on the camera

Figure 20Images obtained by fish eye lenses

Figure 21HDR camera
Fisheye views of a workstation studying glare. With an HDR camera, a false-color overlay of
luminance values on the image
59

CAMERA SETTING: ASSEMBLING
• Mount the fish eye lens on the camera.
• Remove the ring from the lens frame
• Assemble the lens adapter
• Assemble the fish eye lens on the adapter
POSITIONING THE FOCUS:
• Place the camera on the tripod where the measurement is intended
• Put the camera on the right position of a workstation user.
• The height of camera should be 1.2 to 1.3m to mimic the height of the users eye
• Control the camera view to focus on the center of the monitor in the work station
TAKING PICTURES:
Take 4 pictures per the focused point in the same position, One for each of the following settings
of the aperture value: 3.5 4.0 5.6 7.9.

60

4.5.3 The environmental quality measurement cart

Figure 22 EBOT automatic measurement cart
Apart from using the hand held devices to measure the IEQ conditions of the space the research
involved using the environmental measurement cart which is an automation sensing and
measuring device. This cart was developed and built by Prof Joon Ho Choi and his team.
The cart comprises of the following devices:
• Air Temperature sensors
• Humidity level sensors
• Co2 sensors
61

Figure 23LAB view screenshot

The
method
in
which
the
data
was
fed
and
the
usage
of
the
environmental
cart
E-‐
Bot
is

explained
below.

OPERATING INSTRUCTIONS:

1. Connect the battery
2. Plug in the wires to the lap top and place the laptop on the laptop base
3. Open lab view, and feed in data: building name, floor no, workstation no, Radiant
temperature, air velocity and work surface lux, screen lux and reading zone lux
4. Add in the loop count and wait time:
5. Press the start button

62

4.6 Modified COPE Environmental Satisfaction Questionnaire

User sensibility and satisfaction does play an eminent role in evaluating the space and also helps
to figure out how the IEQ conditions influences the building performance. The questions request
the occupants to express their satisfaction with immediate workspace as well as give an opinion
on how much the built environment is beneficial neutral or negative that affect the satisfaction
levels and rating.
The COPE environmental satisfaction questionnaire that was developed by National Research
Council Canada was taken as the basis of preparing my own satisfaction questionnaire since the
COPE questionnaire was developed and designed for similar research motives primarily to
perceive and understand the satisfaction levels of the occupants on those particular current
conditions.
The questionnaire consists of 30 questions on a seven-point scale in addition to five
demographic questions. The questions are designed to assess the performance of the
workspaces. Identify areas that need improvement. The survey includes the following modules
related to IEQ: office layout, furnishings, thermal comfort, air quality, lighting, acoustics and
building maintenance. A seven point semantic differential scale with end points with “very
dissatisfied“ and “very satisfied” is used to evaluate occupant satisfaction quantitatively.
Furthermore a paper based survey is not as convenient but inexpensive, responses were collected
and added to the database enabling the comparison of occupant satisfaction of different buildings
transversely.

63

These results and findings were first analyzed trough statistical analysis Data coding and data
mining were carried out after the data collection process. The effects of these building IEQs on
occupants were investigated and the relation to these findings and the buildings attributes were
studied and compared. The findings, comparisons and results helped to come up with
recommendations to enhance environmental quality of the space.
The first step towards conducting the survey is to first get the IRB American University's
Institutional Review Board approval. I took up the training and completed it to obtain the Citi
Report
64

Figure 24CITI Completion Report
65

Figure 25 satisfaction survey for occupants page 1
66

Figure 26satisfaction survey for occupants page 2
67

Figure 27satisfaction survey for occupants page 3
68

Chapter 5: Indoor Environmental Quality Research of the building:
Data collected
5.1 Data Acquisition System (DAS)

“Data Acquisition System, is a system which acquires data, generally by digitizing analog
channels and storing the data in digital form. These systems can be standalone or married to a
computer and can acquire multiple channels of data.” (Maxim Integrated, 2015).

The data collected through on site measurements using hand held sensors and the Ebot were
stored digitally in excel format, once the data categorizing was done the data is sorted and
digitally uploaded as either values or comments into an Excel chart format.
5 .1 1 Hand held devices measurements:

The indoor environment quality of the office spaces were measured by means of hand held
sensors. Indoor environment attributes such as air quality that comprises co2 levels, Air velocity
and air temperature of each workstation is measured with appropriate hand sensors such as, CO2
sensor, Air velocity sensor Infrared thermometer respectively. Visual comfort levels are
determined with the help of light meters, hence the day light measurements were measured in
every work surface and the light produced from the monitor screen was also measured in order
to find the visual quality and comfort levels of the spaces. Acoustic levels were measured using
a meter in odder to understand the sound levels that exist in each workspace.

69

5.1.2 Air velocity sensor and its measurement:
The air velocity sensor is also called the hot wire anemometer. The air velocities of each
workstation were measured. Two such measurements at 0.1M namely the air velocity at foot
level while the occupant is seated in a chair and at 1.1 M which is approximately the chest level
of the occupant while seated else ware measured and noted down.

According to ASHRAE standards 0.2 m/s is the recommended air velocity in an indoor
environment but according to IRC, a velocity of 0.1m/s or lesser provides increased satisfaction
to the occupants. The air speed permissible levels by ASHRAE 55 (2004) is lesser than or = 40
ft./min, and according to CCOHS (2005) the permissible levels of air velocity are set too lesser
than or = 50 ft./min. It is also noted that ASHRAE allows higher air velocities in warmer and
more humid conditions.
The air velocities that were measured in each workstation are represented graphically below.
Most of the workstations air velocity falls well with in the given ASHRAE 55 standards.

Figure 28 air velocity measurements at 1m
70

Figure 29 air velocity measurements at 1.1 m

3.85% of the sample workspaces are observed to be above the ASHRAE 55 standards and
96.15% are within the ASHRAE 55 standards of permissible air velocity.

5.1.3 Air temperature and its measurement:

The air temperature is measured by the help of infrared thermometer, which infers temperature
from a portion of the thermal radiation sometimes called blackbody radiation. The radiant
temperatures of the ceiling, flooring and the walls are recorded for every workstation
individually and recorded. The relative humidity is also measured; the ambient indoor
temperature is measured with the help of the co2 sensor.
According to ASHRAE 55 standards the warm ceiling radiant temperature asymmetry should be
lesser than or =9.0 degree Fahrenheit (-12.8 degree Celsius). The cool wall radiant temperature
asymmetry should be lesser than or =18.0 degree Fahrenheit (-7.8 degree Celsius).
The floor surface temperatures should be within 19 to 29 degree Celsius according to ASHRAE
55. In cooling seasons the ambient temperatures should be within 23 to 27.8 degree Celsius. And
in heating seasons the indoor temperatures should be within 20.0-25.6 degree Celsius.
71

5.1.4 Indoors air temperatures

Since the workspaces were measured during heating seasons the measured temperatures are
compared to the ASHRAE 55(2004) standers i.e. the temperatures should lie within 20.0-25.6
degree Celsius.

Figure 30 indoor air temperature measurements
The indoor air temperatures are satisfying the ASHRAE 55 standards. I.e. within 20 degree
Celsius and 26 degree Celsius.
5.1.5 Floor surface temperature

Figure 31Floor surface temperature measurements
72

The Floor surface temperatures satisfy the ASHRAE 55 stands by measuring within 19-29
degree Celsius.
5.1.6 Radiant temperature asymmetry:

Figure 32radiant temperature asymmetry measurements for a cool wall

The radiant temperature asymmetry for a cool wall is lesser or = -7.8 degree Celsius according to
ASHRAE 55, the measured radiant temperature asymmetry is much higher.

Figure 33radiant temperature asymmetry measurements for a warm ceiling

73

The radiant temperature asymmetry for a warm ceiling is lesser or = -7.8 degree Celsius
according to ASHRAE 55 .The measured radiant temperature asymmetry for the warm ceiling is
much higher.

5.1.7 CO2 sensors measurement
The carbon di oxide levels were measures with a CO2 sensor in every workstation. The EPA
(IAQ Spec.) states that indoor permissible levels of CO2 should be lesser than 800 ppm and
according to ASHRAE 62 (2004) the permissible levels of CO2 should be 1000 ppm or 700 ppm
above outdoor CO2 levels.

Figure 34carbon di oxide levels measurements
The measured CO2 levels mostly fall within the standards of EPA (IAQ spec.).
16.92 % is observed to be above the EPA (IAQ spec.) standards and 83.08 %within the EPA
(IAQ spec.) standards of permissible CO2 levels.

74

5.1.8 Lighting quality

The Luminance levels were measured with the help of a digital light meter. Light measurements
were obtained in three different locations in a workstation. IL luminance levels of the primary
work surface, the reading or keyboard work surface and the screen lux was noted down.
According to the IESNA RP-1-04 office Lighting Guide (2004) the IL luminance levels for
primary work surface must be Min 200-300-500 lux, and the IL luminance levels for reading or
keyboard surface should be Min 200-300-500 lux. The screen lux luminance levels must be Min
50-70-100 lux.
The UGR (unified glare ratio) should be lesser than or equal to 19 according to the CIE
standards.
5.1.8.1-Worksurface-lux

Figure 35primary work surface lux measurements
75

The measured primary work surface lux lighting levels does not completely fall within the
standards of IESNA RP-1-04 office Lighting Guide (2004)
30 % is observed to be above the 500-lux IESNA RP-1-04 office Lighting Guide (2004)
standards of permissible lighting levels for primary work surface
And 60 %within 200 lux and 500 lux the IESNA RP-1-04 office Lighting Guide (2004)
standards of permissible lighting levels for primary work surface
And 10 % below 200 IESNA RP-1-04 office Lighting Guide (2004) standards of permissible
lighting levels for primary work surface
76

5.1.8.2 Reading or keyboard work surface

Figure 36Reading or keyboard work surface lux measurements

The measured Reading or keyboard work surface lux lighting levels does not completely fall
within the standards of IESNA RP-1-04 office Lighting Guide (2004)
30 % is observed to be above the 500-lux IESNA RP-1-04 office Lighting Guide (2004)
standards of permissible lighting levels for Reading or keyboard work surface.
And 50% within 200 lux and 500 lux the IESNA RP-1-04 office Lighting Guide (2004)
standards of permissible lighting levels for Reading or keyboard work surface.
And 20% below 200 IESNA RP-1-04 office Lighting Guide (2004) standards of permissible
lighting levels for Reading or keyboard work surface.
77

5.1.8.3 Screen lux

Figure 37 Measured screen surface lux, ME
The measured screen lighting levels does not completely fall within the standards of IESNA RP-
1-04 office Lighting Guide (2004)
60 % is observed to be above the 100 lux IESNA RP-1-04 office Lighting Guide (2004)
standards of permissible lighting levels screen omonitor surface.
10% within 50 lux and 100 lux the IESNA RP-1-04 office Lighting Guide (2004) standards of
permissible lighting levels for screen surface and 30 % below 50 IESNA RP-1-04 office
Lighting Guide (2004)standards of permissible lighting levels screen surface.

5.1.8.4 Unified glareratio- HDR camera- using photolux soft ware

Figure 38the calculated UGR
78

The UGR (unified glare ratio) should be lesser than or equal to 19 according to the CIE
standards. The UGR (unified glare ratio) should be lesser than or equal to 19 according to the
CIE standards. The calculated UGR with the help of the fish eye lenses and PHOTOLUX
software mostly complies with the standards.

5.1.9 Acoustic component

The acoustic quality of each space was determined with the help of a sound level meter. The
sensor was used in order to acquire the sound at that particular time at the workspace when the
occupants were still present. Most workspaces were private office spaces and few were open
type office cubicles.

Figure 39 Acoustic Db. measurements

The acoustic component of an office space defines by ASHRAE (2001) is that the acoustic
decibel levels should be lesser than or = 40 dB for an open plan offices space. And the acoustic
decibel for private office space should not be more than 35 dBA.
It is observed that the readings taken at buildings are much higher compared to the given
standards.
79

5.2 E-BOT devices measurements:

The E Bot an environmental cart that was developed by Prof Joon Ho Choi and his team was
used in this research as an experiment to test the environment as well as the environmental cart
that was developed. The Ebot had automated sensors that measured the environmental quality of
the space and recorded the measurements through a computer software name LAB VIEW. The
EBOT was placed at every workstation and let to measure the data by manually inputting few
physical data that was collected with the help of the hand helped sensors.
The EBOT measured four temperatures of the workspace namely at .1m, 0.6m, 1.1m and 1.6 m.
The cart calculated the Mean radiant temperatures as well measured with the MRT could be
measured using a black-globe thermometer
The Relative Humidity and Co2 sensors also calculated data.
5.2.1 The EBot Measurements

The EBOT measured four temperatures of the workspace namely at. 1m, 0.6m, 1.1m and 1.6 m.
The cart calculated the Mean radiant temperatures using a black-globe thermometer.

Figure 40Mean radiant temperature of Ebot
80

According the ASHRAE 55(2004) standards the maximum air temperature or mean radiant
temperature in an office space during cooling season should be within 24 degree c alias and 28
degree Celsius. And in heating season the MRT should be within 20 degree Celsius and 26
degree Celsius,

It is observed that the EBOT s calculated measurements varies and seems to be very high
compares to the given standards of ASHRAE 55.

Figure 41CO2 levels measured by EBOT

The carbon di oxide levels were measures with a CO2 sensor in every workstation. The EPA
(IAQ Spec.) states that indoor permissible levels of CO2 should be lesser than 800 ppm and
according to ASHRAE 62 (2004) the permissible levels of CO2 should be 1000 ppm or 700 ppm
above outdoor CO2 levels.
The measured CO2 levels mostly fall within the standards of EPA (IAQ spec.).
The EBOT also recorded the Date and time as the measurements were taken.
The RH values according to the ASHRAE 62 (1999) should fall between 30-60%, the values
calculated by the EBOT does not comply with the standards.

81

Building
physical
attributes,
Work
Station
-‐Physical
attributes
of
the
workspaces.

Floors,
location

Figure 42 work station – location core/perimeter
5.3 Environmental quality analysis survey questionnaire results

Questionnaires were given to all the occupants working in the workstations in all seven buildings
where the IEQ measurements were obtained to better understand their environmental comfort
and their experiences with the work place. One hundred and nineteen completed questionnaires
were received from the occupants.
Demographic questions:
Details such as Age Gender job position, working hours are the first five questions in the
questionnaire. The results are represented in the form of pie charts with percentages of the given
sample size.

82

Q1 How many years have you been in this building?

Figure 43Questionnaire result –work experience

Table 8 Questionnaire result-wok experience
42% of the surveyed occupants have spent less than one year in that particular work
station/office space. 39% of surveyed occupants have spent 3 to 5 years. And 19% of the
surveyed occupants have spent 1 to 2 years in this particular office space.

1-‐2
Years
3-‐5
Years
Less
than
1

23
46
50

83

Q2 In a week number of hours spent at your workstation?

Figure 44Questionnaire result-hours spent
54 % of the surveyed occupants sample spend more than 30 hours during a week at their
workstation. 27% of the collected sample spends 11 to 30 hours in a week and 19% of the
sample spends 10 or lesser number of hours in a week at their workstation

Q3 What is your age?

Figure 45Questionnaire result-age group
18-‐29
30-‐39
40-‐49
50-‐59

66
23
18
12

Table 9Questionnaire result-age group
56%

19%

15%

10%

Age
groups

18-‐29

30-‐39

40-‐49

50-‐59

84

56 % of the sample sizes were within the age group 18 to 29. 19% of the surveyed occupants
were within the age group 30 to 39. 15% of the sample size were within the age group 40 to 49
and 10 % of the sample size were within the age group 50 to 59.

Q4 What is your gender?

Figure 46Questionnaire result-gender

Table 10Questionnaire result-gender

The Female occupants and the male occupants who answered the questionnaire were almost
equal in number. There were 60 female sample occupant survey feedback responses and 59 male
occupant survey feedback responses.

Female
Male

60
59

85

Q5 What is your Job category?

Figure 47 Questionnaire result-job categories

Table 11 Questionnaire result-job categories

51% of the occupants who answered the questionnaire were students .24% of the sample size
were administrational staff, 19 % of them were Technical staff and 6% of the occupants in the
sample were Faculty.

From Q6 onwards the survey is on the basis of a seven-point scale, ranging from very
satisfactory to neutral to very unsatisfactory. The questionnaires were interpreted to
numbers for a better understanding. The numbers aids to represent the results in
graphical format. Very unsatisfactory was represented by a -3 and neutral was 0 and very
satisfactory was given as +3.

24%

6%

51%

19%

Job
category

Admin

Faculty

Student

Technical

Admin
Faculty
Student
Technical

29
7
60
23

86

Q6 How satisfied are you with your job/ institution?

Figure 48 Questionnaire result-job satisfactions

Table 12 Questionnaire result-job satisfactions
This question was asked to the occupants to get a general idea on the satisfaction levels of their
current job, since that might affect their perception of the work environment too. Only 1% of the
sample answered that they were very unsatisfied with their job, and 40 % of the occupants in the
collected sample were satisfied, and 23% of them were very satisfied and 15 % had a neutral
opinion.

1%

1%

2%

15%

18%

40%

23%

Job
satisfaction

Very

unsatis`ied

Unsatis`ied

Mildly

unsatis`ied

Neutral
(0)

Very

unsatisfied

Unsatisfie
d

Mildly

unsatisfied

Neutral
(0)
Mildly

satisfied

Satisfied
Very

satisfie
d

1
1
2
18
21
48
28

87

Q7 How satisfied are you with the Size of your personal workspace to accommodate your work,
materials& visitors?

Figure 49Questionnaire result-size of workspace

Very

unsatisfied

Unsatisfie
d

Mildly

unsatisfied

Neutral
(0)
Mildly

satisfied

Satisfie
d

Very

satisfi
ed

4
4
8
19
25
36
23

Table 13Questionnaire result-size of workspace

When asked about the size of their workspace and if they had enough space to accommodate
their personal belongings and office material. 4% of the sample answered that they were very
unsatisfied and 30% of the occupants in the collected sample were satisfied, and 19% of them
were very satisfied and 16% had a neutral opinion.

4%

3%

7%

16%

21%

30%

19%

Size
of
work
space

Very
unsatis`ied

Unsatis`ied

Mildly

unsatis`ied

Neutral
(0)

Mildly
satis`ied

Satis`ied

88

Q8 How satisfied are you with the level of privacy?

Figure 50 Questionnaire result-level of privacy

Table 14Questionnaire result-level of privacy

The privacy levels in an office work space is vital since a person spends half his day at his or her
workplace, the occupants satisfaction levels about their privacy levels were that 5% of the
sample answered that they were very unsatisfied and 27% of the occupants in the collected
sample were satisfied, and 19% of them were very satisfied and 21 % had a neutral opinion.

5%

7%

4%

21%

17%

27%

19%

Privacy

Very
unsatis`ied

Unsatis`ied

Mildly

unsatis`ied

Neutral
(0)

Mildly
satis`ied

Satis`ied

Very
satis`ied

Very

unsatisfied

Unsatisfied
Mildly

unsatisfied

Neutral
(0)
Mildly

satisfied

Satisfied
Very

satisfied

6
8
5
25
20
33
23

89

Q9 How satisfied are you with ability to alter physical conditions in your work area? (E.g.
operable windows, blinds)

Figure 51Questionnaire Alter physical conditions

Very

unsatisfied

Unsatisfied
Mildly

unsatisfied

Neutral
(0)
Mildly

satisfied

Satisfied
Very

satisfied

8
16
15
28
21
22
9

Table 15Questionnaire Alter physical conditions
Altering physical conditions according to their needs is very necessary in an work environment,
altering the physical setting such as windows, curtains / blinds can help the occupants to be more
comfortable, 7% of the sample answered that they were very unsatisfied and 18 % of the
occupants in the collected sample were satisfied, and 8% of them were very satisfied and 23 %
had a neutral opinion.

7%

13%

13%

23%

18%

18%

8%

Alter
physical
conditions

Very
unsatis`ied

Unsatis`ied

Mildly
unsatis`ied

Neutral
(0)

Mildly
satis`ied

Satis`ied

Very
satis`ied

90

Q10 How satisfied are you with your access to a view of outside from where you sit?

Figure 52Questionnaire results Access to outside views

Very

Unsatisfied

Unsatisfie
d

Mildly

Unsatisfied

Neutral
(0)
Mildly

satisfied

Satisfied
Very

satisfied

11
8
14
26
21
18
21

Table 16Questionnaire results Access to outside views

Ability to have access to outside views will enhance the work atmosphere and will help the
occupants relax while doing so. 9% of the sample answered that they were very unsatisfied and
15 % of the occupants in the collected sample were satisfied, and 18% of them were very
satisfied and 22 % had a neutral opinion.

9%

7%

12%

22%

17%

15%

18%

Access
to
outside
views

Very
unsatis`ied

Unsatis`ied

Mildly
unsatis`ied

Neutral
(0)

Mildly
satis`ied

Satis`ied

Very
satis`ied

91

Q11 How satisfied are you with the Distance between you and other people you work with?

Figure 53Questionnaire results distance between workstation

Very

unsatisfied

Unsatisfied
Mildly

unsatisfied

Neutral
(0)
Mildly

satisfied

Satisfied
Very

satisfied

5
6
4
22
24
34
26

Table 17Questionnaire results distance between workstation

When asked the occupants about how satisfied or not with their distance between them and other
workstations 4% of the sample answered that they were very unsatisfied and 23% of the
occupants in the collected sample were satisfied, and 22 % of them were very satisfied and 18 %
had a neutral opinion.

4%

5%

3%

18%

20%

28%

22%

Distance
between

workstations

Very

unsatis`ied

Unsatis`ied

Mildly

unsatis`ied

Neutral
(0)

Mildly
satis`ied

92

Q12 How satisfied are you with the Degree of enclosure of your work area by walls, screens or
furniture?

Figure 54Questionnaire results degree of enclosure
Very

unsatisfied

Unsatisfied
Mildly

unsatisfied

Neutral
(0)
Mildly

satisfied

Satisfied
Very

satisfied

2
6
13
22
28
29
19

Table 18Questionnaire results degree of enclosure

The workstation setting should be designed in a manner that it able the workers functionally and
also provide them with the amount privacy to carry out their task efficiently. Degree of enclosure
for a works station plays an important role in an office setting 2% of the sample answered that
they were very unsatisfied and 24 % of the occupants in the collected sample were satisfied, and
16% of them were very satisfied and 18 % had a neutral opinion.

2%

5%

11%

18%

24%

24%

16%

Degree
of
Enclousure
of

work
area

Very

unsatis`ied

Unsatis`ie
d

Mildly

unsatis`ied

Neutral

(0)

Mildly

satis`ied

Satis`ied

Very

satis`ied

93

Q13 How satisfied is you with the current temperature right at now at your workspace?

Figure 55Questionnaire results current temperature level

Table 19Questionnaire results current temperature levels

The question about the satisfaction levels of their current temperature was asked since the
outside temperatures and the air temperatures were measured at the same time the questionnaire
was given to fill. That way it gives a better understanding of the temperature levels and is
possible to see if the current settings meet standards. 2% of the sample answered that they were
very unsatisfied and 28 % of the occupants in the collected sample were satisfied, and 16% of
them were very satisfied and 9 % had a neutral opinion.

2%

8%

11%

9%

26%

28%

16%

current
temperature

Very
unsatis`ied

Unsatis`ied

Mildly
unsatis`ied

Neutral
(0)

Mildly
satis`ied

Satis`ied

Very
satis`ied

Very

unsatisfied

Unsatisfied
Mildly

unsatisfied

Neutral
(0)
Mildly

satisfied

Satisfied
Very

satisfied

3
9
13
11
31
33
19

94

Q14 How satisfied are you with Thermostats? (Operability)

Figure 56 Questionnaire results thermostats operability

Table 20Questionnaire results thermostats operability

Being able to control the temperature levels is important, the ability to operate thermostats and
the opinions were that 9% of the sample answered that they were very unsatisfied and 11 % of
the occupants in the collected sample were satisfied, and 7% of them were very satisfied and 26
% had a neutral opinion.

9%

20%

11%

26%

16%

11%

7%

Thermostats

Very
unsatis`ied

Unsatis`ied

Mildly
unsatis`ied

Neutral
(0)

Mildly
satis`ied

Satis`ied

Very
satis`ied

Very

unsatisfied

Unsatisfied
Mildly

unsatisfied

Neutral
(0)
Mildly

satisfied

Satisfied
Very

satisfied

11
23
13
31
19
13
8

95

Q15 How satisfied are you with the current air quality in your work space (i.e. stuffy/stale air,
cleanliness, odors)?

Figure 57Questionnaire results Air quality

Table 21Questionnaire results Air quality

The air quality comprises the air cleanliness, stuffiness and odors .3% of the sample answered
that they were very unsatisfied and 23 % of the occupants in the collected sample were satisfied,
and 13% of them were very satisfied and 27 % had a neutral opinion.

3%

7%

8%

27%

19%

23%

13%

Air
Quality

Very
unsatis`ied

Unsatis`ied

Mildly

unsatis`ied

Neutral
(0)

Mildly
satis`ied

Satis`ied

Very
satis`ied

Very

unsatisfied

Unsatisfied
Mildly

unsatisfied

Neutral
(0)
Mildly

satisfied

Satisfied
Very

satisfied

4
8
10
32
22
27
15

96

Q16 How satisfied are you with the amount of noise from other people’s conversations while
you are at your workstation?

Figure 58Questionnaire results noise from conversation

Table 22Questionnaire results noise from conversation

When asked about the noise that they hear from other people’s conversations, and if at all it
disturbs them. 3% of the sample answered that they were very unsatisfied with the present
condition and 17 % of the occupants in the collected sample were satisfied, and 9% of them were
very satisfied and 26 % had a neutral opinion.

3%

13%

13%

26%

19%

17%

9%

Amount
of
noise
from
other

people’s
conversations

Very
unsatis`ied

Unsatis`ied

Mildly
unsatis`ied

Neutral
(0)

Mildly
satis`ied

Satis`ied

Very

unsatisfied

Unsatisfied
Mildly

unsatisfied

Neutral
(0)
Mildly

satisfied

Satisfied
Very

satisfied

4
15
15
31
22
20
11

97

Q17 How satisfied are you with the amount of background noise (i.e. not speech, noise from
mech system) you hear at your workstation?

Figure 59Questionnaire results noise from background
Very

unsatisfied

Unsatisfied
Mildly

unsatisfied

Neutral
(0)
Mildly

satisfied

Satisfied
Very

satisfied

4
16
11
22
21
31
13

Table 23Questionnaire results noise from background
The opinion about the background noises i.e. noise caused by mechanical systems etc. , the
occupants satisfaction levels of the present conditions were , 3% of the sample answered that
they were very unsatisfied and 26 % of the occupants in the collected sample were satisfied, and
11% of them were very satisfied and 19 % had a neutral opinion.

3%

14%

9%

19%

18%

26%

11%

Background
Noise

Very

unsatis`ied

Unsatis`ied

Mildly

unsatis`ied

Neutral
(0)

98

Q18 How satisfied are you with the Light for computer work?

Figure 60Questionnaire results- light for computer work
Very

unsatisfied

Unsatisfied
Mildly

unsatisfied

Neutral
(0)
Mildly

satisfied

Satisfied
Very

satisfied

5
4
8
21
27
28
26

Table 24Questionnaire results- light for computer work

The amount of light for a computer oriented task is very important and should be of the right
amount too much brightness or darkness can cause discomfort for the occupants, 4% of the
sample answered that they were very unsatisfied and 23 % of the occupants in the collected
sample were satisfied, and 22% of them were very satisfied and 18 % had a neutral opinion.

4%

3%

7%

18%

23%

23%

22%

Light
for
computer
work

Very
unsatis`ied

Unsatis`ied

Mildly
unsatis`ied

Neutral
(0)

Mildly
satis`ied

Satis`ied

Very
satis`ied

99

Q19 How satisfied are you with the amount of reflected light or glare in the computer screen?

Figure 61Questionnaire results- reflected light or glare

Very

unsatisfied

Unsatisfied
Mildly

unsatisfied

Neutral
(0)
Mildly

satisfied

Satisfied
Very

satisfied

2
8
16
13
30
30
20

Table 25Questionnaire results- reflected light or glare

Glare
is
a
major
issue;
especially
if
there
is
glare
on
the
computer
screen
it
makes
it
really

difficult
to
work.
2%
of
the
sample
answered
that
they
were
very
unsatisfied
with
the

amount
of
glare
on
computer
screens.
And
25
%
of
the
occupants
in
the
collected
sample

were
satisfied,
and
17%
of
them
were
very
satisfied
and
11
%
had
a
neutral
opinion.

2%
7%

13%

11%

25%

25%

17%

ReNlected
light
or
glare

Very
unsatis`ied

Unsatis`ied

Mildly
unsatis`ied

Neutral
(0)

Mildly
satis`ied

Satis`ied

Very
satis`ied

100

Q20 How satisfied are you with the amount of direct glare (high luminance’ s that are visible
from a viewers position; example: unshielded luminaire) from light fixtures?

Figure 62Questionnaire results- glare from light fixtures

Very

unsatisfied

Unsatisfied
Mildly

unsatisfied

Neutral
(0)
Mildly

satisfied

Satisfied
Very

satisfied

3
3
9
27
21
40
16

Table 26Questionnaire results- glare from light fixtures

Direct
glare
from
light
fixtures
on
computer
screen
or
work
surface
can
be
disturbing,
2%

of
the
sample
answered
that
they
were
very
unsatisfied
and
34
%
of
the
occupants
in
the

collected
sample
were
satisfied,
and
13%
of
them
were
very
satisfied
and
23
%
had
a

neutral
opinion.

2%

2%

8%

23%

18%

34%

13%

Direct
glare
from
light
Nixtures

Very

unsatis`ied

Unsatis`ied

Mildly

unsatis`ied

Neutral
(0)

Mildly

satis`ied

Satis`ied

Very
satis`ied

101

Q21 How satisfied are you with the Amount of direct glare (high luminance’ s that are visible
from a viewers position; example: unshielded luminaire) from daylight?

Figure 63Questionnaire results- glare from day light

Table 27Questionnaire results- glare from day light

Direct sun can also produce glare on work surface, 3% of the sample answered that they were
very unsatisfied and 29 % of the occupants in the collected sample were satisfied, and 13% of
them were very satisfied and 22 % had a neutral opinion.

3%

4%

11%

22%

18%

29%

13%

Direct
glare
from
day

light

Very
unsatis`ied

Unsatis`ied

Mildly
unsatis`ied

Neutral
(0)

Mildly
satis`ied

Satis`ied

Very
satis`ied

Very

unsatisfied

Unsatisfied
Mildly

unsatisfied

Neutral
(0)
Mildly

satisfied

Satisfied
Very

satisfied

3
5
13
26
21
35
16

102

Q22 How satisfied are you with the quality of lighting in your work area? (Combined artificial
and Day lighting)

Figure 64Questionnaire results- Quality of lighting

Table 28Questionnaire results- Quality of lighting

Lighting in a workspace or workstation is very important to accomplish the task with ease,
occupant’s answers about the lighting conditions of the space were only 2% of the sample
answered that they were very unsatisfied and 27 % of the occupants in the collected sample were
satisfied, and 20% of them were very satisfied and 15 % had a neutral opinion.

2%

5%

10%

15%

21%

27%

20%

Quality
of
lighting

Very
unsatis`ied

Unsatis`ied

Mildly
unsatis`ied

Neutral
(0)

Mildly
satis`ied

Satis`ied

Very
satis`ied

103

Q23 How satisfied are you with general buildings and office layout? (Workstation layout)

Figure 65Questionnaire results- building and office layout

Very

unsatisfied

Unsatisfied
Mildly

unsatisfied

Neutral
(0)
Mildly

satisfied

Satisfied
Very

satisfied

4
10
15
28
29
22
11

Table 29Questionnaire results- building and office layout

The office layout helps the function of the space to take place in an effective manner, the
occupants opinion on the office layout and settings were 3% of the sample answered that they
were very unsatisfied and 19 % of the occupants in the collected sample were satisfied, and 9%
of them were very satisfied and 24 % had a neutral opinion.

3%

8%

13%

24%

24%

19%

9%

Buildings
and
ofNice
layout

Very
unsatis`ied

Unsatis`ied

Mildly
unsatis`ied

Neutral
(0)

Mildly
satis`ied

Satis`ied

Very
satis`ied

104

Q24 How satisfied are you with the colors and textures of flooring, furniture and surface
finishes?
.
Figure 66Questionnaire results- colors textures and surface finishes

Table 30Questionnaire results- colors textures and surface finishes

Colors and Texture or the décor in the interior spaces causes definite impact on the occupants,
their satisfaction levels were, 3% of the sample answered that they were very unsatisfied and 19
% of the occupants in the collected sample were satisfied, and 14% of them were very satisfied
and 28 % had a neutral opinion.

3%

11%

9%

28%

16%

19%

14%

Colors
and
textures
of

Nlooring,
furniture
and

surface
Ninishes

Very
unsatis`ied

Unsatis`ied

Mildly

unsatis`ied

Neutral
(0)

Mildly
satis`ied

Satis`ied

Very

unsatisfied

Unsatisfied
Mildly

unsatisfied

Neutral
(0)
Mildly

satisfied

Satisfied
Very

satisfied

4
13
11
33
19
22
17

105

Q25 What is your opinion of the Air movement in your work area?

Figure 67Questionnaire results- Air movement

Table 31Questionnaire results- Air movement

Ventilation helps in reducing the stuffiness of the place, but air movement also includes the air
through air conditioners and other air vents. 7% of the sample answered that they were very
unsatisfied and 11 % of the occupants in the collected sample were satisfied, and 3% of them
were very satisfied and 33 % had a neutral opinion.

7%

16%

13%

33%

17%

11%

3%

Air
movement

Very

unsatis`ied

Unsatis`ied

Mildly

unsatis`ied

Neutral
(0)

Mildly

satis`ied

Satis`ied

Very

satis`ied

Very

unsatisfied

Unsatisfied
Mildly

unsatisfied

Neutral
(0)
Mildly

satisfied

Satisfied
Very

satisfied

9
21
16
42
22
14
4

106

Q26 What is your opinion of the ambient temperature in your work area?

Figure 68Questionnaire results- ambient temperature

Table 32Questionnaire results- ambient temperature

Ambient temperature or air temperature satisfaction levels were 1% of the sample answered that
they were very unsatisfied and 15 % of the occupants in the collected sample were satisfied, and
4% of them were very satisfied and 37 % had a neutral opinion.

1%

9%

9%

37%

25%

15%

4%

Ambient
temperature

Very
unsatis`ied

Unsatis`ied

Mildly
unsatis`ied

Neutral
(0)

Mildly
satis`ied

Satis`ied

Very
satis`ied

Very

unsatisfied

Unsatisfied
Mildly

unsatisfied

Neutral
(0)
Mildly

satisfied

Satisfied
Very

satisfied

1
11
10
44
30
18
5

107

Q27 What is your opinion of the lighting conditions in your work area?

Figure 69Questionnaire results- lighting conditions

Table 33Questionnaire results- lighting conditions

When asked about the general lighting conditions 1% of the sample answered that they were
very unsatisfied and 24 % of the occupants in the collected sample were satisfied, and 9% of
them were very satisfied 22 % were mildly satisfied and 31 %, 3% were unsatisfied and 31 %
had a neutral opinion.

1%

3%

10%

31%

22%

24%

9%

Lighting
conditions

Very
unsatis`ied

Unsatis`ied

Mildly

unsatis`ied

Neutral
(0)

Mildly
satis`ied

Satis`ied

Very
satis`ied

Very

unsatisfied

Unsatisfied
Mildly

unsatisfied

Neutral
(0)
Mildly

satisfied

Satisfied
Very

satisfied

1
4
12
37
26
29
10

108

Q28 What is your opinion on the noise level/acoustic conditions in your work area?

Figure 70Questionnaire results- Acoustic condition

Table 34Questionnaire results- Acoustic condition

When asked bout the general acoustic condition 5% of the sample answered that they were very
unsatisfied and 17 % of the occupants in the collected sample were satisfied, and 2% of them
were very satisfied and 29 % had a neutral opinion.

5%

8%

12%

29%

27%

17%

2%

Noise
level/acoustic

conditions

Very
unsatis`ied

Unsatis`ied

Mildly
unsatis`ied

Neutral
(0)

Mildly
satis`ied

Satis`ied

Very

unsatisfied

Unsatisfied
Mildly

unsatisfied

Neutral
(0)
Mildly

satisfied

Satisfied
Very

satisfied

6
9
14
35
32
20
3

109

Q29 How satisfied are you with the indoor Environment quality of your workspace?

Figure 71 Questionnaire results- IEQ

V
very

unsatisfi
ed

Unsatisfie
d

Mildly

unsatisfie
d

Neutral
(0)
ilMildly

satisfied

Satisfied
vVery
satisfied

1
6
12
31
34
27
8

Table 35 Questionnaire results- IEQ

The final question was asked to get an idea from the occupants as to what they think about the
indoor environmental quality of the space. 2% of the sample answered that they were very
unsatisfied and 23 % of the occupants in the collected sample were satisfied, and 7% of them
were very satisfied 28 % were mildly satisfied and 26 % had a neutral opinion.

1%
5%

10%

26%

28%

23%

7%

Indoor
Environment
quality

Very
unsatis`ied

Unsatis`ied

Mildly
unsatis`ied

Neutral
(0)

Mildly
satis`ied

Satis`ied

Very
satis`ied

110

Chapter 6: Analysis of Data (Discussion)
6.1 Occupant feedback survey data vs. measured data
1.Ambient Temperature Satisfaction levels of the users vs. measured ambient temperature
Discussion:
The ambient temperature will differ from building to building, workspace to workspace
depending on the movement in the space and also the distance between the workspace and the
cooling equipment also is a factor that contributes to the ambient temperature of the space.
Figure 72, Figure73 and Figure 74 shows the results by plotting the individual thermal comfort
levels of the occupants versus measured temperature (°C) levels of their respective workspaces.
The differences between the means are not statistically significant. P value is 0.3 which is
greater than 0.05. So we can say there is no significant relationship between the measured
temperature and thermal comfort satisfaction data that we have collected. Most occupants have
either neutral or satisfactory thermal conditions according to the sample data collected.
This may also be due to the fact that they have become accustomed to the thermal conditions of
the space.

Figure 72 Ambient Temperature Satisfaction levels of the users vs. measured ambient temperature , Figure 73 Ambient
Temperature Satisfaction levels of the users vs. measured ambient temperature
111

Correlation Analysis

Pearson correlation of AMBIENT TEMPERATURE and AMBIENT TEMPERATURE (0 C) = -0.085730
P-Value = 0.3539

Figure 74 Ambient Temperature Satisfaction levels of the users vs. measured ambient temperature

2. Air quality Satisfaction levels of the users vs. measured CO2 levels
Discussion:
Since Indoor air quality does not only influence the comfort levels of the workers on an office
space it also important due to the reason it may affect their health, it may cause problems such as
head ache, irritation in nose lungs or eyes and thus creating an atmosphere not friendly enough
for concentrating on work. There are many factors that affect the indoor air quality of a space.
These include high CO2 levels, where in the space does not get fresh air coming into it.
The measured CO2 levels mostly fall within the standards of EPA (IAQ spec.).
16.92 % is observed to be above the EPA (IAQ spec.) standards and 83.08 %within the EPA
(IAQ spec.) standards of permissible CO2 levels. Figure 76, Figure 77 and Figure 78 shows the
results by plotting the individual Air Quality comfort levels of the occupants versus measured
CO2 levels (ppm) of their respective workspaces.
112

The differences between the means are not statistically significant. P value is 0.4 which is
greater than 0.05. So we can say there is no significant relationship between the measured Co2
levels and Air Quality satisfaction data that we have collected through the survey

Figure 75Air quality Satisfaction levels of the users vs. measured CO2 levels ,Figure 76Air quality Satisfaction levels of the
users vs. measured CO2 levels

Figure 77Air quality Satisfaction levels of the users vs. measured CO2 levels interval plot

Correlation Analysis

Pearson correlation of AIR QUALITY SATISFACTION and CO2 IN PPM = 0.067934
P-Value = 0.4648

113

3. Air movement satisfaction levels of the users vs. measured air velocity
Discussion:
Air movement or Ventilation helps in reducing the stuffiness of the place, it is a major factor that
influences IAQ of the space. Air movement also includes the air through air conditioners and
other air vents. 7% of the sample answered that they were very unsatisfied and 11 % of the
occupants in the collected sample were satisfied, and 3% of them were very satisfied and 33 %
had a neutral opinion.
The air speed permissible levels by ASHRAE 55 (2004) is lesser than or = 40 ft./min, and
according to CCOHS (2005) the permissible levels of air velocity are set to be lesser than or =
50 ft./min. The measured air velocities using hand held sensors: 3.85% is observed to be above
the ASHRAE 55 standards and 96.15% within the ASHRAE 55 standards of permissible air
velocity.
Figure 79 and Figure 80 shows the results by plotting the individual Air movement comfort
levels of the occupants versus measured air velocity (ft./min) of their respective workspaces.
The differences between the means are statistically significant. P value is 0.06. So we can say
there is marginable significance in the relationship between the measured air velocities and air
movement satisfaction data that has been collected. Therefore,
it
seems
that
higher satisfaction
with air movement contribute to higher IAQ satisfaction
114

Figure 78 Air movement Satisfaction levels of the users vs. measured Air velocity ;Figure 79Air movement Satisfaction levels of
the users vs. measured Air velocity

Correlation

Pearson correlation of AIR MOVEMENT SATISFACTION and AIR VELOCITY in FT/MIN = -0.170807
P-Value = 0.0644

4.Noise level satisfaction levels of the users vs. measured acoustic decibel
Discussion:
Acoustical comfort is one of the factors that are not taken into much consideration during the
design process. Noise in work spaces are majorly caused due to speakerphones, low partition
heights, ringing phones, noisy copy machines, and office chatter. And also noise due to HVAC
systems and other mechanical equipment’s may cause considerable amount of disturbing noise.
The noise affects the workers by distracting them from concentrating on their work but the
noises are not high enough to cause any health issues. This acoustical discomfort will provide a
non-ideal work environment to the workers. According to the occupant feed back survey 5% of
the sample answered that they were very unsatisfied and 17 % of the occupants in the collected
sample were satisfied, and 2% of them were very satisfied and 29 % had a neutral opinion
115

The acoustic component of an office space defines by ASHRAE (2001) is that the acoustic
decibel levels should be lesser than or = 40 dBA for an open plan offices space. And the acoustic
decibel for private office space should not be more than 35 dB A. It is observed that the readings
taken at buildings are much higher compared to the given standards.
Figure 81, Figure 82 and Figure 83 shows the results by plotting the individual acoustical
component comfort levels of the occupants versus measured acoustical decibel (DbA) of their
respective workspaces.
The differences between the means are statistically significant. P value is 0.05. So we can say
there is marginable significance in the relationship between the measured acoustic DB and noise
level satisfaction data that has been collected through the occupant feedback survey.

Figure 80 Noise level Satisfaction levels of the users vs. measured Acoustic decibel ,Figure 81Noise level Satisfaction levels of
the users vs. measured Acoustic decibel
Correlation

Pearson correlation of NOISE LEVEL SATISFACTION and ACOUSTIC DECIBLE (DbA) = -0.055762
P-Value = 0.5469

116

Figure 82 Noise level Satisfaction levels of the users vs. measured Acoustic decibel

5.Lighting (combined artificial and day light) satisfaction levels of the users vs. measured
work area lux and reading surface lux.
Discussion:
The measured lighting levels in the workspaces satisfies IESNA codes for both work area lux
and reading area lux however the plotted chart shows us the satisfaction levels of the over all
lighting conditions with the measured lighting levels of their workspaces, its understood that 40-
60 lux levels seems to have the maximum satisfaction levels, a very low light level contributes to
over all dissatisfaction in the lighting condition of the occupants.

117

Figure 83Lighting (combined artificial and day light) Satisfaction levels of the users vs. measured work area lux and Reading
surface lux.

6.Lighting condition satisfaction level vs. measured work area luminance level (lux)

Discussion:
Task lighting and ambient lighting in an office space is very vital. With light being a key
component of vision and hence proper lighting strategies in an office space will have a
significant impact on the comfort and productivity levels of occupants.
The most common issues that cause poor office lighting is lights that are too dim and lights that
is too harsh. The measured primary work surface lux lighting levels does not completely fall
within the standards of IESNA RP-1-04 office Lighting Guide (2004)

Figure 85 and Figure 86 shows the results by plotting the individual lighting comfort levels of
the occupants versus measured work area luminance levels (lux) of their respective workspaces.
The differences between the means are statistically significant. P value in ANOVA is 0.4. So we
can say there is no statistical significance in the relationship between the measured work area lux
and lighting comfort level satisfaction data that has been collected through the occupant
feedback survey.
118

Figure 84 Lighting condition satisfaction level vs. measured work area luminance level (lux),Figure 85 Lighting condition
satisfaction level vs. measured work area luminance level (lux)

One Way ANOVA -Analysis of Variance

Source DF Adj SS Adj MS F-Value P-Value
LIGHTING SATISFACTION 6 6310.646 1051.77432 0.96 0.4525

Table 36 Lighting condition satisfaction level vs. measured work area luminance level (lux)

7.Lighting condition satisfaction level vs. reading area lux

Discussion:
The measured Reading or keyboard work surface lux lighting levels does not completely fall
within the standards of IESNA RP-1-04 office Lighting Guide (2004)
Figure 87 and Figure 88 shows the results by plotting the individual lighting comfort levels of
the occupants versus measured work area luminance levels (lux) of their respective workspaces.
The differences between the means are not statistically significant. P value In ANOVA is 0.5. So
we can say there is no statistical significance in the relationship between the measured reading
area lux and lighting comfort level satisfaction data that has been collected through the occupant
feedback survey.
119

Figure 86 Lighting condition satisfaction level vs. reading area lux ,Figure 87 Lighting condition satisfaction level vs. reading
area lux

One Way ANOVA-Analysis of Variance

Source DF Adj SS Adj MS F-Value P-Value
LIGHTING SATISFACTION 6 4085.433 680.905423 0.77 0.5939

Table 37 Lighting condition satisfaction level vs. reading area lux

8. Satisfaction levels of direct glare caused by light fixtures of the users vs. measured UGR
Discussion:
Direct glare from light fixtures on computer screen or work surface can be disturbing, 2% of the
sample answered that they were very unsatisfied and 34 % of the occupants in the collected
sample were satisfied, and 13% of them were very satisfied and 23 % had a neutral opinion.
The UGR (unified glare ratio) should be lesser than or equal to 19 according to the CIE
standards. Figure 89 and Figure 90 shows the results by plotting the individual glare from light
fixtures comfort levels of the occupants versus measured UGR using fish eye lenses images and
photo lux software (lux) of their respective workspaces.
120

The differences between the means are not statistically significant. P value is 0.2. So we can say
there is no statistical significance in the relationship between the calculated UGR and glare
caused due to light fixtures and the satisfaction levels sample that has been collected through the
occupant feedback survey.

Figure 88 Satisfaction levels of direct glare caused by light fixtures of the users vs. measured UGR ,Figure 89 Satisfaction levels
of direct glare caused by light fixtures of the users vs. measured UGR
Correlation

Pearson correlation of GLARE FROM LIGHT FIXTURES and UGR IN LUX = 0.114205
P-Value = 0.2263

9. Satisfaction levels of direct glare caused by Day light of the users vs. measured UGR
Discussion:
Direct
sun
can
also
produce
glare
on
work
surface,
3%
of
the
sample
answered
that
they

were
very
unsatisfied
and
29
%
of
the
occupants
in
the
collected
sample
were
satisfied,
and

13%
of
them
were
very
satisfied
and
22
%
had
a
neutral
opinion.

The UGR (unified glare ratio) should be lesser than or equal to 19 according to the CIE
standards. And the measured data mostly is in compliance with the standards.
Figure 91, Figure 92 and Figure 93 shows the results by plotting the individual glare caused due
to daylight (comfort levels) of the occupants versus calculated UGR (lux) of their respective
workspaces.
121

The differences between the means are not statistically significant. P value is 0.4. So we can say
there is no statistical significance in the relationship between the calculated UGR and amount of
glare comfort or discomfort level that has been collected through the occupant feedback survey.

Figure 90 Satisfaction levels of direct glare caused by Day light of the users vs. measured UGR Figure 91 Satisfaction levels of
direct glare caused by Day light of the users vs. measured UGR

Figure 92 Satisfaction levels of direct glare caused by Day light of the users vs. measured UGR
Correlation

Pearson correlation of GLARE DUE TO DAYLIGHT and UGR in lux = 0.068499
P-Value = 0.4690

122

10. Satisfaction levels of glare from the computer screen of the users vs. measured
computer screen lux
Discussion:
Glare is a major issue; especially if there is glare on the computer screen it makes it really
difficult to work. 2% of the sample answered that they were very unsatisfied with the amount of
glare on computer screens. And 25 % of the occupants in the collected sample were satisfied,
and 17% of them were very satisfied and 11 % had a neutral opinion.

The measured screen surface lux lighting levels does not completely fall within the standards of
IESNA RP-1-04 office Lighting Guide (2004)

Figure 94 and Figure 95 shows the results by plotting the individual glare caused due to
computer screen (comfort levels) of the occupants versus measured computer screen lux (lux) of
their respective workspaces.

The differences between the means are marginable statistically significant. P value is 0.06. So
we can say there is marginable statistical significance in the relationship between the measured
screen lux and amount of glare on computer screen and their comfort or discomfort levels that
has been collected through the occupant feedback survey. As the screen lux increases the
satisfaction levels of glare from computer screen lux also increases

123

Figure 93 Satisfaction levels of glare from the computer screen of the users vs. measured computer screen lux Figure 94
Satisfaction levels of glare from the computer screen of the users vs. measured computer screen lux
Correlation

Pearson correlation of GLARE FROM COMPUTER SCREEN and SCREEN LUX = -0.169955
P-Value = 0.0670

11. Satisfaction levels of indoor environment quality of the users vs. measured CO2 levels
The measured CO2 levels mostly fall within the standards of EPA (IAQ spec.).
16.92 % is observed to be above the EPA (IAQ spec.) standards and 83.08 %within the EPA
(IAQ spec.) standards of permissible CO2 levels. Figure 96 and Figure 97 shows the results by
plotting the individual Air Quality comfort levels of the occupants versus measured CO2 levels
(ppm) of their respective workspaces.

The differences between the means are statistically significant. P value in ANOVA is 0.04. So
we can say there is statistical significance in the relationship between the measured CO2 and
IEQ comfort or discomfort levels that has been collected through the occupant feedback survey.
There are increased satisfaction levels with 700 ppm -1000 ppm of co2 and IEQ dissatisfaction
levels at 1250 ppm of co2 levels.
124

Figure 95 Satisfaction levels of indoor environment quality of the users vs. measured CO2 levels Figure 96 Satisfaction levels of
indoor environment quality of the users vs. measured CO2 levels
One- Way ANOVA- Analysis of Variance

Source DF Adj SS Adj MS F-Value P-Value
IEQ SATISFACTION LEVELS 6 925174.29 154195.714 3.36 0.0044

Table 38 Satisfaction levels of indoor environment quality of the users vs. measured CO2 levels

6.2 Occupant feedback survey data vs. occupant feedback survey
6.2.1 Gender wise analysis:

The Female occupants and the male occupants who answered the questionnaire were almost
equal in number. 60 Female sample occupant survey feedback responses and 59 male occupant
survey feedback responses.

125

12.Gender of the users vs. Satisfaction levels of indoor environment quality of the users
Discussion:
According to the survey The IEQ satisfaction were that 2% of the sample answered that they
were very unsatisfied and 23 % of the occupants in the collected sample were satisfied, and 7%
of them were very satisfied and 26 % had a neutral opinion.
Figure 98 and Figure 99 shows the results by plotting the individual IEQ (comfort levels) of the
occupants versus their respective genders. This analysis was performed to see if there are any
major variations with their onions on IEQ. The sample size had almost equal sample size of male
and female. The plotted chart shows a mean of male sample that is more unsatisfied the
differences between the means are not statistically significant. P value is 0.4. So we cannot say
there is statistical significance in the relationship between genders and the IEQ comfort or
discomfort levels that has been collected through the occupant feedback survey.

2 sample T Test

T-Value DF P-Value
0.73 116 0.4696

Table 39 Gender of the users vs. Satisfaction levels of indoor environment quality of the users

Figure 97 Gender of the users vs. Satisfaction levels of indoor environment quality of the users Figure 98 Gender of the users vs.
Satisfaction levels of indoor environment quality of the users
126

13.Gender of the users vs. satisfaction levels of ambient temperature.
Discussion:
According to the survey Ambient temperature or air temperature satisfaction levels were 1% of
the sample answered that they were very unsatisfied and 15 % of the occupants in the collected
sample were satisfied, and 4% of them were very satisfied and 37 % had a neutral opinion.

Figure 100 and Figure 101 shows the results by plotting the individual ambient temperature
(comfort levels) of the occupants versus their respective genders. This analysis was performed to
see if there are any major variations with their opinions on the indoor temperature comfort
levels. The sample size had almost equal sample size of male and female. The plotted chart
shows us mean of male and female sample has no differences between them. But the means are
not statistically significant. Since P value is 0.3 so we cannot say there is statistical significance
in the relationship between genders and the ambient temperature comfort or discomfort levels
that has been collected through the occupant feedback survey.

2 sample T Test

T-Value DF P-Value
0.96 114 0.3410

Table 40 Gender of the users vs. Satisfaction levels of ambient temperature.

127

Figure 99 Gender of the users vs. Satisfaction levels of ambient temperature. Figure 100 Gender of the users vs. Satisfaction
levels of ambient temperature.

14.Gender of the users vs. satisfaction levels of acoustic conditions
Discussion:
According to the survey about the acoustic condition of the workspace 5% of the sample
answered that they were very unsatisfied and 17 % of the occupants in the collected sample were
satisfied, and 2% of them were very satisfied and 29 % had a neutral opinion.

Figure 102 and Figure 103 shows the results by plotting the individual Acoustic condition
(comfort levels) of the occupants versus their respective genders. This analysis was performed to
see if there are any major variations with their opinions in discomforts caused due to noise
prevailing in the office environment. The plotted chart shows a mean of male sample that is
more unsatisfied the differences between the means are not statistically significant. Since P value
is 0.3. So we cannot say there is statistical significance in the relationship between genders and
the acoustical comfort or discomfort levels that has been collected through the occupant
feedback survey.

128

2 sample T Test

T-Value DF P-Value
0.96 114 0
.3410

. Table 41 Gender of the users vs. Satisfaction levels of Acoustic conditions

Figure 101 Gender of the users vs. Satisfaction levels of Acoustic conditions Figure 102 Gender of the users vs. Satisfaction
levels of Acoustic conditions

15.Gender of the users vs. Satisfaction levels of Lighting conditions
Discussion:
According to the survey about the general lighting conditions 1% of the sample answered that
they were very unsatisfied and 124 % of the occupants in the collected sample were satisfied,
and 9% of them were very satisfied and 31 % had a neutral opinion.

Figure 104 and Figure 105 shows the results by plotting the individual lighting condition
(comfort levels) of the occupants versus their respective genders. This analysis was performed to
see if there are any major variations with their opinions in discomforts caused due to excess or
dim lighting conditions prevailing in the office environment. The plotted chart shows a mean of
129

male sample that is slightly more unsatisfied the differences between the means are not
statistically significant. Since P value is 0.3. So we cannot say there is statistical significance in
the relationship between genders and the lighting conditions comfort or discomfort levels that
has been collected through the occupant feedback survey.

2 sample T Test

T-Value DF P-Value
1.15
14 0.
2534

Table 42 Gender of the users vs. Satisfaction levels of Lighting conditions

Figure 103 Gender of the users vs. Satisfaction levels of Lighting conditions Figure 104 Gender of the users vs. Satisfaction
levels of Lighting conditions

16.Gender of the users vs. Satisfaction levels of Air movement conditions
Discussion:
Ventilation helps in reducing the stuffiness of the place, but air movement also includes the air
through air conditioners and other air vents
130

According to the survey about the Ventilation and air movement, 7% of the sample answered
that they were very unsatisfied and 11 % of the occupants in the collected sample were satisfied,
and 3% of them were very satisfied and 33 % had a neutral opinion.

Figure 106 and Figure 107 shows the results by plotting the individual air movement (comfort
levels) of the occupants versus their respective genders. This analysis was performed to see if
there are any major variations with their opinions in discomforts caused due to excess air or
stuffy office environment. The plotted chart shows a mean of male sample that is slightly more
unsatisfied the differences between the means are not statistically significant. Since P value in
ANNOVA is 0.57. So we cannot say there is statistical significance in the relationship between
the genders and the air movement comfort or discomfort levels that has been collected through
the occupant feedback survey.
2 sample T Test

T
Value
DF
P-Value

56 116 0.5777

Table 43 Gender of the users vs. Satisfaction levels of Air movement conditions

Figure 105 Gender of the users vs. Satisfaction levels of Air movement conditions Figure 106 Gender of the users vs.
Satisfaction levels of Air movement conditions
131

6.2.2 Age wise analysis

The participants of the survey belonged to varied age groups where in, 56 % of the sample sizes
were within the age group 18 to 29. 19% of the surveyed occupants were within the age group
30 to 39. 15% of the sample size were within the age group 40 to 49 and 10 % of the sample size
were within the age group 50 to 59.

17.Age of the users vs. Satisfaction levels of ambient temperature conditions
Discussion:
According to the survey Ambient temperature or air temperature satisfaction levels were that 1%
of the sample answered that they were very unsatisfied and 15 % of the occupants in the
collected sample were satisfied, and 4% of them were very satisfied and 37 % had a neutral
opinion.
Figure 108 and Figure 109 shows the results by plotting the individual air temperature
satisfaction (comfort levels) of the occupants versus their respective age groups. This analysis
was performed to see if there are any major variations with their opinions in discomforts caused
due to too much cold or hot whether in office environment. And how it differs with the age
groups. It is a proven fact that older people are more sensitive to weather that younger people.
The plotted chart shows a mean of 18-29 samples is lowest, but the differences between the
means are not statistically significant. Since P value in ANNOVA is 0.9. So we cannot say there
is statistical significance in the relationship between the age groups and the air temperature
comfort or discomfort levels that has been collected through the occupant feedback survey
132

Figure 107 Age of the users vs. Satisfaction levels of ambient temperature conditions Figure 108 Age of the users vs. Satisfaction
levels of ambient temperature conditions.
One-way ANOVA- Analysis of Variance

Source DF Adj SS Adj MS F-Value P-Value
AGE GROUPS 4 0.714830 0.17870742 0.11 0.9801

Table 44 Age of the users vs. Satisfaction levels of ambient temperature conditions.

18.Age of the users vs. Satisfaction levels of lighting conditions
Discussion:
According to the survey Ambient temperature or air temperature satisfaction levels were that 1%
of the sample answered that they were very unsatisfied and 15 % of the occupants in the
collected sample were satisfied, and 4% of them were very satisfied and 37 % had a neutral
opinion.
Figure 110 and Figure 111 shows the results by plotting the individual air temperature
satisfaction (comfort levels) of the occupants versus their respective age groups. This analysis
was performed to see if there are any major variations with their opinions in discomforts caused
due to too much cold or hot whether in office environment. And how it differs with the age
groups. It is a proven fact that older people are more sensitive to weather that younger people.
133

The plotted chart shows a mean of 18-29 samples is lowest, but the differences between the
means are not statistically significant. Since P value in ANNOVA is 0.9. So we cannot say there
is statistical significance in the relationship between the age groups and the air temperature
comfort or discomfort levels that has been collected through the occupant feedback survey.

Figure 109 Age of the users vs. Satisfaction levels of lighting conditions Figure 110 Age of the users vs. Satisfaction levels of
lighting conditions
One-way ANOVA- Analysis of Variance

Source DF Adj SS Adj MS F-Value P-Value
AGE GROUPS 4 3.265080 0.81627012 0.47 0.7544

Table 45 Age of the users vs. Satisfaction levels of lighting conditions

19.Age of the users vs. Satisfaction levels of acoustic conditions
Discussion:
Acoustics is an important attribute in office building design. Noise that exists in an office
atmosphere can cause irritation and can lead to increased stress for occupants (Evans et al. 2000,
Sundstrom 1994)
134

The survey results for general acoustic condition satisfaction was that 5% of the sample
answered that they were very unsatisfied and 17 % of the occupants in the collected sample were
satisfied, and 2% of them were very satisfied and 29 % had a neutral opinion.
Figure 112, Figure 113 and Figure 114 shows the results by plotting the individual Acoustic
condition (comfort levels) of the occupants versus their respective age groups. This analysis was
performed to see if there are any major variations with their opinions in discomforts caused due
to too loud noises that may cause irritation and lack of concentration in an office environment.
And if at all the results vary with the age groups. The plotted chart shows a mean of 18-29
samples is lowest, but the differences between the means are not statistically significant. Since P
value in ANNOVA is 0.8. So we cannot say there is statistical significance in the relationship
between the age groups and the acoustic condition comfort or discomfort levels that has been
collected through the occupant feedback survey.
However its understood that moderating the noise level is needed to improve the well-being of
occupants especially in open-plan office environments, since it may cause stress and discomfort
to the occupants.

Figure 111 Age of the users vs. Satisfaction levels of acoustic conditions Figure 112 Age of the users vs. Satisfaction levels of
acoustic conditions
135

Figure 113 Age of the users vs. Satisfaction levels of acoustic conditions
One-way ANOVA- Analysis of Variance

Source DF Adj SS Adj MS F-Value P-Value
AGE GROUPS 4 3.081920 0.77048010 0.38 0.8233

Table 46 Age of the users vs. Satisfaction levels of acoustic conditions

20.Age of the users vs. IEQ Satisfaction levels
Discussion:
The survey results for the question for opinion on their Indoor environmental quality, 2% of the
sample answered that they were very unsatisfied and 23 % of the occupants in the collected
sample answered that they were satisfied, and 7% of them were very satisfied 28 % were mildly
satisfied and 26 % had a neutral opinion.

Figure 115 and Figure 116 shows the results by plotting the individual IEQ (comfort levels) of
the occupants versus their respective age groups. This analysis was performed to see if there the
opinions of the occupants on the IEQ comfort levels changes with age. The plotted chart shows
a mean of 40-49 samples is lowest, this age group represents mostly faculty /Admin/ Technical
staff job category. The differences between the means are marginally statistically significant.
136

Since P value in ANNOVA is 0.06 so we can say that there is marginal statistical significance in
the relationship between the age groups and the IEQ comfort or discomfort levels that has been
collected through the occupant feedback survey. Age group 50- 59 have the most IEQ
satisfaction level and age group 40-49 have the least IEQ satisfaction level.

Figure 114 Age of the users vs. IEQ Satisfaction levels Figure 115 Age of the users vs. IEQ Satisfaction levels

One-way ANOVA- Analysis of Variance

Source DF Adj SS Adj MS F-Value P-Value
AGE GROUPS 4 14.876172 3.71904291 2.31 0.0619

Table 47 Age of the users vs. IEQ Satisfaction levels

6.2.3 Lighting and Glare:

Task lighting and ambient lighting in an office space is very vital. With light being a key
component of vision and hence proper lighting strategies in an office space will have a
significant impact on the comfort and productivity levels of occupant. The most common issues
that cause poor office lighting is lights that are too dim and lights that is too harsh. Especially
137

when it comes to computer-based task, it is a challenge for lighting designers the computer
screen by itself is a light source. Today’s office spaces involve a countable amount of computer-
based tasks. Glare is a major concern in lighting design, the screen itself can cause glare if the
brightness and contrast controls are not properly adjusted. Glare also can be caused due to light
sources, shiny objects or walls and light from windows. Eye discomfort caused due to glare also
forces the user to strain the operators' eyes especially for long hours in a day. To analyze and
study if these factors have affected the occupants the following analytical comparisons and
groupings were made.

21.Amount of light for computer based task Satisfaction levels vs. glare caused due to
computer screen Satisfaction levels.
Discussion
Figure 117 and Figure 118 shows the results by plotting the individual satisfaction levels of the
occupants lighting conditions for their computer based task versus satisfaction levels of glare
caused due to their computer screen. The plotted chart shows a means are statistically
significant. Since P value in ANNOVA is <0.0001 sighting conditions for their computer-based
task versus satisfaction levels of glare caused due to their computer screen. The plotted chart
tells us that the dissatisfaction levels of the occupants with the lighting condition are similar to
the dissatisfaction levels of the glare on the screen. Higher satisfaction with lighting conditions
contributes to higher satisfaction with glare due to screen satisfaction levels.
138

Figure 116 Amount of light for computer based task Satisfaction levels vs. glare caused due to computer screen Satisfaction
levels Figure 117 Amount of light for computer based task Satisfaction levels vs. glare caused due to computer screen
Satisfaction levels

One-way ANOVA- Analysis of Variance

Source DF Adj SS Adj MS F-Value P-Value
GLARE FROM COMPUTER SCREEN 6 98.988342 16.4980570 9.57 <0.0001

Table 48 Amount of light for computer-based task Satisfaction levels vs. glare caused due to computer screen Satisfaction levels

The following chart represents the satisfaction of glare conditions caused due to both the
light sources vs. the general lighting condition satisfaction levels of the occupants.
Discussion:
Glare can be caused when natural light or artificial light with very high luminance level enters
into the occupants field of view, this can cause discomfort to the occupant in a great level. This
problem due to glare can occur when the sunlight enters directly through an opening / window or
when light sources are incorrectly placed in the workspace. Hence window openings and
artificial lighting must designed and placed in a manner such that it minimizes glare. The plotted
chart shows us the occupants satisfaction of glare caused sue to artificial lighting and day light
versus the overall lighting condition satisfaction levels. From the chart we can understand that
with the satisfaction of glare levels seems to contribute to over all lighting condition satisfaction
level of the occupants.
139

Figure 118 light sources vs. the general lighting condition satisfaction levels of the occupants

6.2.4 Occupants comfort with the office setting and privacy levels:

22.Privacy level Satisfaction levels vs. general office layout Satisfaction levels.
Discussion:
Insufficient privacy in the workplace can cause great amount of distress to occupants, privacy
not only includes visual privacy but also audio privacy. There has always been a battle between
privacy and interaction at the workplace. Occupants must be able to interact at the same time
have their privacy for working and being able to be comfortable
Figure 120, Figure 121 and Figure 122 shows the results by plotting the individual satisfaction
levels of the occupant’s privacy level versus satisfaction levels of general office layout. The
plotted chart shows a means are statistically significant. Since P value in ANNOVA is <0.0001.
It can be understood that higher dissatisfaction levels of privacy conditions contributes to higher
dissatisfaction of the office layout. Therefore an office space with optimum privacy will result in
a better office layout.

140

Figure 119 Privacy level Satisfaction levels vs. general office layout Satisfaction levels Figure 120 Privacy level Satisfaction
levels vs. general office layout Satisfaction levels

Figure 121 Privacy level Satisfaction levels vs. general office layout Satisfaction levels

One-way ANOVA- Analysis of Variance

Source DF Adj SS Adj MS F-Value P-Value
OFFICE LAYOUT 6 109.135603 18.1892672 9.27 <0.0001

Table 49 Privacy level Satisfaction levels vs. general office layout Satisfaction levels

141

23. Privacy level Satisfaction levels vs. Acoustic satisfaction levels.
Discussion:
Work space dissatisfaction can be causes due to many factors but noise or acoustical discomfort
leads to reduced effectiveness in work implementation, causes higher stress levels in the
employees and in turn causes job dissatisfaction The majority of the acoustic discomfort
perceived by an occupant is complaints that relate to speech privacy. Speech privacy majorly is
the feeling or fear of overhearing others conversation or being over heard, Hence occupants
might feel a little background noise might be more comfortable than a very quiet environment
but it is important to keep in mind=d too much nose in a space can cause distraction too.
The plotted chart shows the results of Privacy level Satisfaction levels vs. Acoustic satisfaction
levels. The P value is high hence the means are not statistically significant, a relationship
between these two satisfaction levels cannot be established.

Figure 122 Privacy level Satisfaction levels vs. Acoustic satisfaction levels Figure 123 Privacy level Satisfaction levels vs.
Acoustic satisfaction levels.
One-way Anova
Analysis of Variance

Source DF Adj SS Adj MS F-Value P-Value
ACOUSTIC SATISFACTION LEVEL 6 18.432470 3.07207828 1.11 0.3623

Table 50 Privacy level Satisfaction levels vs. Acoustic satisfaction level
142

24.Distance between workstations Satisfaction levels vs. general office layout Satisfaction
levels.
Discussion:
The amount working area / space needed for any one individual is determined by considering the
task performed by the worker. The designer also keeps in mind the overall area of the office, the
furniture layout, storage space and utility spaces. Though there are no clear standards for
specified for distance between workstations for optimum privacy levels. Privacy is an important
factor that needs to be taken into account in an office design.
Figure 125, Figure 126 and Figure 127 shows the results by plotting the individual satisfaction
levels of the occupant’s satisfaction levels in terms of distance between their workstations versus
satisfaction levels of general office layout. The plotted chart shows a means are statistically
significant. Since P value in ANNOVA is <0.0001. It can be understood that higher the
dissatisfaction levels of distance between their workstations contributes to higher dissatisfaction
levels of the office layout.

Figure 124 Distance between workstations Satisfaction levels vs. general office layout Satisfaction levels.
Figure 125 Distance between workstations Satisfaction levels vs. general office layout Satisfaction levels.

143

Figure 126 Distance between workstations Satisfaction levels vs. general office layout Satisfaction levels.

One-way ANOVA- Analysis of Variance

Source DF Adj SS Adj MS F-Value P-Value
OFFICE LAYOUT 6 110.941126 18.4901877 10.63 <0.0001

Table 51 Distance between workstations Satisfaction levels vs. general office layout Satisfaction levels

25.Noise levels from people’s conversation vs. Noise from background noise (e.g.
mechanical systems) Satisfaction levels.
Discussion:
Noise in office spaces can cause a negative mood to the workers. There are studies that show
that certain level of noises can ‘incapacitate’ the workers and thus resulting in the persons
inability to accomplice a task thereby leading to stress (hedge 1982). Noise in an office space is
not only caused by conversations but also from HVAC system telephone speakers copying
machines and other mechanical systems.

Figure 128 and Figure 129 shows the results by plotting the individual satisfaction levels of
noise caused due to conversation (office chatter) versus occupant’s satisfaction levels of noise
caused due to background noise such as mechanical systems etc.
144

The plotted chart shows a means are statistically significant. Since P value in ANNOVA is
<0.0001. It can be understood that higher the dissatisfaction levels of noise caused due to
conversation (office chatter) contributes to higher dissatisfaction levels of noise caused due to
background noise such as mechanical systems etc.

Figure 127 Noise levels from people’s conversation vs. Noise from background noise (e.g. mechanical systems) Satisfaction
levels Figure 128 Noise levels from people’s conversation vs. Noise from background noise (e.g. mechanical systems)
Satisfaction levels
One-way ANOVA- Analysis of Variance

Source DF Adj SS Adj MS F-Value P-Value
BACKGROUND NOISE 6 107.185124 17.8641874 10.07 <0.0001

Table 52 Noise levels from people’s conversation vs. Noise from background noise (e.g. mechanical systems) Satisfaction levels

26. Air movement satisfaction level vs. Indoor Air Quality
Discussion:
Figure 130 and Figure 131 shows the results by plotting the individual satisfaction levels of the
occupant’s air movement satisfaction levels versus satisfaction levels of Indoor air quality. The
plotted chart shows a means are statistically significant. Since P value in ANNOVA is <0.0001.
145

It can be understood that higher the satisfaction levels of air movement contributes to higher
satisfaction levels of Indoor air Quality. The air speed permissible levels by ASHRAE 55 (2004)
is lesser than or = 40 ft./min, and according to CCOHS (2005) the permissible levels of air
velocity are set to be lesser than or = 50 ft./min. According to the measured data the air
velocities
3.85% is observed to be above the ASHRAE 55 standards and 96.15% within the ASHRAE 55
standards of permissible air velocity. Since most of the workspaces are compliance to the
standards, higher satisfaction with air movement contributes to higher IAQ satisfaction. A
certain level of air movement seems to contribute to occupants’ IAQ satisfaction.

Figure 129 Air movement satisfaction level vs. Indoor Air Quality Figure 130 Air movement satisfaction level vs. Indoor Air
Quality
One-way ANOVA- Analysis of Variance

Source DF Adj SS Adj MS F-Value P-Value
AIR MOVEMENT 6 113.316675 18.8861125 12.31 <0.0001

Table 53 Air movement satisfaction level vs. Indoor Air Quality

146

6.2.5 Indoor environmental quality Vs. environmental factors and
occupant demographics.

The occupants survey results on the indoor environmental quality of the space was that 2% of
the sample answered that they were very unsatisfied and 23 % of the occupants in the collected
sample were satisfied, and 7% of them were very satisfied 28 % were mildly satisfied and 26 %
had a neutral opinion.

27Job position vs. IEQ satisfaction levels
Discussion:
The sample of occupants belonged various job categories of which 29 of the sample size were
admin staff, 7 were faculty members 60 were students and 23 were Technical staff. I.e. 51% of
the occupants who answered the questionnaire were students .24% of the sample size were
administrational staff, 19 % of them were Technical staff and 6% of the occupants in the sample
were Faculty. This analysis was carried out to understand if their opinions on the IEQ
satisfaction levels changes with their job category.
Figure 132 and Figure 133 shows the results by plotting the individual IEQ satisfaction levels of
the occupants versus their job category. The results of this chart can be interpreted that the
admin staff s median is more skewed towards the center of the chart, which indicates their
neutral opinion, while most the students who answered had a neutral opinion a considerable
number might have mild dissatisfaction levels with the IEQ conditions since the curve is slightly
skewed towards the left, while the technical staff have a satisfied opinion likewise the faculty
samples who answered the questionnaire.

147

Figure 131 Job position vs. IEQ satisfaction levels Figure 132 Job position vs. IEQ satisfaction levels

28.IEQ Satisfaction levels vs. Air Quality Satisfaction levels.
Discussion:
Figure 134 and Figure 135 shows the results by plotting the individual occupant satisfaction
levels of Indoor air quality versus occupant’s satisfaction levels of IEQ. The plotted chart shows
a means are statistically significant. Since P value in ANNOVA is <0.0001. It can be understood
that higher the dissatisfaction levels of air quality contributes to higher dissatisfaction levels of
Indoor environmental quality.

Figure 133 IEQ Satisfaction levels vs. Air Quality Satisfaction levels Figure 134 IEQ Satisfaction levels vs. Air Quality
Satisfaction levels

148

One-way ANOVA
Analysis of Variance

Source DF Adj SS Adj MS F-Value P-Value
AIR QUALITY 6 47.879064 7.97984408 5.94 <0.0001

Table 54 IEQ Satisfaction levels vs. Air Quality Satisfaction levels

29.IEQ Satisfaction levels vs. Air Movement Satisfaction levels
Discussion:
Figure 136 and Figure 137 shows the results by plotting the individual occupant satisfaction
levels of Indoor air movement versus occupant’s satisfaction levels of IEQ. The plotted chart
shows a means are statistically significant. Since P value in ANNOVA is <0.0034. It can be
understood that higher satisfaction levels of air movement contributes to higher satisfaction
levels of Indoor environmental quality. The air speed permissible levels by ASHRAE 55 (2004)
is lesser than or = 40 ft./min, and according to CCOHS (2005) the permissible levels of air
velocity are set to be lesser than or = 50 ft./min. According to the measured data the air
velocities
3.85% is observed to be above the ASHRAE 55 standards and 96.15% within the ASHRAE 55
standards of permissible air velocity. Since most of the workspaces are compliance to the
standards, higher satisfaction with air movement contributes to higher IEQ satisfaction. A certain
level of air movement seems to contribute to occupants’ IEQ satisfaction.

149

Figure 135 IEQ Satisfaction levels vs. Air Movement Satisfaction levels Figure 136 IEQ Satisfaction levels vs. Air Movement
Satisfaction levels
One-way ANOVA- Analysis of Variance

Source DF Adj SS Adj MS F-Value P-Value
AIR MOVEMENT 6 31.183351 5.19722523 3.48 0.0034

Table 55 IEQ Satisfaction levels vs. Air Movement Satisfaction levels

30.IEQ Satisfaction levels vs. Temperature Satisfaction levels
Discussion:

Figure 138 and Figure 139 shows the results by plotting the individual IEQ satisfaction levels of
the occupants versus their ambient temperature satisfaction levels. The plotted chart shows that
differences between the means are not statistically significant. Since P value in ANNOVA is 0.2
so we cannot say there is statistical significance in the relationship between the IEQ satisfaction
levels and ambient Temperature comfort levels that has been collected through the occupant
feedback survey.

150

Figure 137 IEQ Satisfaction levels vs. Temperature Satisfaction levels Figure 138 IEQ Satisfaction levels vs. Temperature
Satisfaction levels

One-way ANOVA- Analysis of Variance

Source DF Adj SS Adj MS F-Value P-Value
TEMPERATURE 6 13.168543 2.19475709 1.33 0.2506

Table 56 IEQ Satisfaction levels vs. Temperature Satisfaction levels

31.IEQ Satisfaction levels Vs. Lighting condition Satisfaction levels
Discussion:
Figure 140 and Figure 141 shows the results by plotting the individual occupant satisfaction
levels of lighting condition versus occupant’s satisfaction levels of IEQ. The plotted chart shows
a means are statistically significant. Since P value in ANNOVA is <0.0031. It can be understood
that higher satisfaction levels of lighting condition contributes to higher satisfaction levels of
Indoor environmental quality

151

Figure 139 IEQ Satisfaction levels Vs. Lighting condition Satisfaction levels Figure 140 IEQ Satisfaction levels Vs. Lighting
condition Satisfaction levels.

One-way ANOVA- Analysis of Variance

Source DF Adj SS Adj MS F-Value P-Value
LIGHTING 6 22.613391 3.76889855 2.40 0.0319

Table 57 IEQ Satisfaction levels Vs. Lighting condition Satisfaction levels.

32.IEQ Satisfaction levels vs. Acoustic condition Satisfaction levels
Figure 142 and Figure 143 shows the results by plotting the individual IEQ satisfaction levels of
the occupants versus their Acoustic satisfaction levels. The plotted chart shows that differences
between the means are not statistically significant. Since P value in ANNOVA is 0.53 Hence we
cannot say there is statistical significance in the relationship between the IEQ satisfaction levels
and ambient and acoustic condition satisfaction levels that has been collected through the
occupant feedback survey.

152

Figure 141 IEQ Satisfaction levels vs. Acoustic condition Satisfaction levels Figure 142 IEQ Satisfaction levels vs. Acoustic
condition Satisfaction levels
One-way ANOVA Analysis of Variance

Source DF Adj SS Adj MS F-Value P-Value
ACOUSTIC CONDITION 6 8.575694 1.42928241 0.84 0.5388

Table 58 IEQ Satisfaction levels vs. Acoustic condition Satisfaction levels

33. IEQ Satisfaction levels vs. Spatial condition Satisfaction levels
Discussion:
Figure 144 and Figure 145 shows the results by plotting the individual occupant satisfaction
levels of office layout i.e. spatial quality versus occupant’s satisfaction levels of IEQ. The
plotted chart shows that the means are statistically significant. Since P value in ANNOVA is
<0.0001. It can be understood that higher satisfaction levels of spatial Quality contributes to
higher satisfaction levels of Indoor environmental quality

153

Figure 143 . IEQ Satisfaction levels vs. Spatial condition Satisfaction levels Figure 144 . IEQ Satisfaction levels vs. Spatial
condition Satisfaction levels
One-way ANOVA Analysis of Variance

Source DF Adj SS Adj MS F-Value P-Value
SPATIAL QUALITY 6 46.217271 7.70287854 5.67 <0.0001

Table 59. IEQ Satisfaction levels vs. Spatial condition Satisfaction levels

34. IEQ satisfaction levels versus Thermostat controls.
Discussion:
Figure 146 and Figure 147 shows the results by plotting the individual occupant satisfaction
levels of controllability of thermostats versus occupant’s satisfaction levels of IEQ. The plotted
chart shows that the means are statistically significant. Since P value in ANNOVA is <0.0051.
There is a significant relationship between the means and it can be understood that higher
satisfaction levels of thermostat controllability contributes to higher satisfaction levels of Indoor
environmental quality.

154

Figure 145 IEQ satisfaction levels versus Thermostat controls Figure 146 IEQ satisfaction levels versus Thermostat controls

One-way ANOVA -Analysis of Variance

Source DF Adj SS Adj MS F-Value P-Value
THERMOSTAT CONTROLS 6 29.133556 4.85559261 3.29 0.0051

Table 60 IEQ satisfaction levels versus Thermostat controls

6.2.6 STEP WISE REGRESSION for IEQ satisfaction level and all
other survey questions:

The table below is the questions that had a p value lesser 0.05 when stepwise regression was
performed. These questions are further analyzed using one-way ANOVA to establish the
relationship between the indoor environmental quality satisfaction levels with the other factors
satisfaction levels.

155

Multiple Regression Results:
Step 5
Constant 0.14961
Q18- Lighting for computer task 0.15
T-Value 1.8
P-Value 0.074
Q11-Distance between work stations 0.22
T-Value 3.17
P-Value 0.002
Q25-Air movement 0.176
T-Value 2.71
P-Value 0.008
Q20-Glare from light fixtures 0.158
T-Value 1.84
P-Value 0.068
Q14-Accesses to thermostats 0.101
T-Value 1.8
P-Value 0.075
S 0.986
R-Sq 43.96
R-Sq(adj) 41.43
Mallows Cp -8.1
Table 61 STEP WISE REGRESSION FOR IEQ satisfaction level and all other questions
156

35.IEQ satisfaction levels vs. Distance between workstation (privacy)
Discussion:
Figure 148 and Figure 149 shows the results by plotting the individual occupant satisfaction
levels of distance between their workstations versus occupant’s satisfaction levels of IEQ. The
plotted chart shows that the means are statistically significant. Since P value in ANNOVA is
<0.0001. There is a significant relationship between the means and It can be understood that
higher satisfaction levels of distance between their workstation/work area contributes to higher
satisfaction levels of Indoor environmental quality.

Figure 147 IEQ satisfaction levels vs. Distance between workstation Figure 148 IEQ satisfaction levels vs. Distance between
workstation
One way ANOVA-Analysis of Variance

Source DF Adj SS Adj MS F-Value P-Value
Q11 6 60.617766 10.1029609 8.22 <0.0001

Table 62 IEQ satisfaction levels vs. Distance between workstation

157

36.IEQ satisfaction levels vs. Light for computer work
Discussion:
Figure 150 and Figure 151 shows the results by plotting the individual occupant satisfaction
levels for light for their computer based tasks versus occupant’s satisfaction levels of IEQ. The
plotted chart shows that the means are statistically significant. Since P value in ANNOVA is
<0.0001. There is a significant relationship between the means and It can be understood that
higher satisfaction levels of light for their computer based tasks contributes to higher satisfaction
levels of Indoor environmental quality

Figure 149 IEQ satisfaction levels vs. Light for computer work Figure 150 IEQ satisfaction levels vs. Light for computer work
One way ANOVA-Analysis of Variance

Source DF Adj SS Adj MS F-Value P-Value
LIGHT FOR COMPUTER WORK 6 59.283473 9.88057889 8.20 <0.0001

Table 63 IEQ satisfaction levels vs. Light for computer work
.

158

37.IEQ satisfaction levels vs Direct glare from light fixtures.
Discussion:
Figure 152 and Figure 153 shows the results by plotting the individual occupant satisfaction
levels for direct glare caused due to light fixtures versus occupant’s satisfaction levels of IEQ.
The plotted chart shows that the means are statistically significant. Since P value in ANNOVA is
<0.0001. There is a significant relationship between the means and it can be understood that
higher satisfaction for direct glare caused due to light fixtures contributes to higher satisfaction
levels of Indoors environmental quality

Figure 151 IEQ satisfaction levels vs Direct glare from light fixtures. Figure 152 IEQ satisfaction levels vs Direct glare from
light fixtures.
One way ANOVA-Analysis of Variance

Source DF Adj SS Adj MS F-Value P-Value
DIRECT GLARE FROM FIXTURES 6 51.071513 8.51191877 6.66 <0.0001

Table 64 IEQ satisfaction levels vs Direct glare from light fixtures.
.

159

38.OVERALL IEQ versus IEQ Factors:

Figure 153 OVERALL IEQ versus IEQ Factors
One way ANOVA-Analysis
of Variance

IEQ FACTORS P-Value
AIR QUALITY <0.0001
AIR MOVEMENT 0.003
TEMPERATURE 0.25
LIGHTING 0.03
ACOUSTIC CONDITION 0.5
SPATIAL CONDITION <0.0001

Table 65 OVERALL IEQ versus IEQ Factors

160

ONE-‐WAY
ANOVE
:IEQ
VERSUS
IEQ
FACTORS

By performing ANOVA with IEQ satisfaction levels and the factors that influence IEQ majorly,
it is evident that there are significant p values and hence a relationship between the factors
namely Air quality, Air movement, Lighting and Spatial quality which have p values lesser than
0.05 in ANOVA and Indoor environmental Quality can be established. The satisfaction levels of
the factors contribute to the overall satisfaction levels of IEQ

Figure 154 IEQ versus Air quality Figure 155 IEQ versus Air movement

Figure 156 IEQ versus Temperature Figure 157 IEQ versus lighting conditions

161

Figure 158 IEQ versus Acoustic conditions Figure 159 IEQ versus Spatial conditions
162

6.3 Occupant feedback survey vs. physical setting
39.IEQ satisfaction levels vs. Workspace /work station orientation.
Discussion:
Figure x shows the results by plotting the individual occupants work station position that was
recorded versus occupant’s IEQ satisfaction levels. The plotted chart shows that the means are
not statistically significant. Since P value is 0.2. There is no significant relationship between the
means. Though the mean of occupants who’s workstation is locate in perimeter od the office
layout, seem to have more IEQ satisfaction level a relationship cannot be established.
Descriptive Statistics: IEQ SATISFACTION LEVELS

T-Value DF P-Value
-1.23 115 0.2226

Figure 160 Table 66 IEQ satisfaction levels vs. Workspace /work station orientation Figure 161 Table 67 IEQ satisfaction levels
vs. Workspace /work station orientation

163

40.Air movement satisfaction levels vs. Workspace /work station orientation.
Discussion:
The plotted chart shows us the Air movement satisfaction levels vs. the workstation position,
from the chart we can understand that occupants located in the core of the office layout seem
slightly more dissatisfied than the occupants siting on the perimeter of the office layout, The air
movement might be slightly lesser since access to windows in core areas is minimal.

Figure 162 Air movement satisfaction levels vs. Workspace /work station orientation

41. Temperature satisfaction levels vs. Workspace /work station orientation.
Discussion:
The plotted chart shows us the temperature condition satisfaction levels vs. the workstation
position, from the chart we can understand that occupants located in the perimeter of the office
layout have much more higher satisfaction levels compared to that of occupants on the core
region of the office layout.
164

Figure 163 Temperature satisfaction levels vs. Workspace /work station orientation

42. Lighting satisfaction levels vs. Workspace /work station orientation.
Discussion:
The plotted chart shows us the lighting condition satisfaction levels vs. the workstation position,
from the chart we can understand that occupants located in the perimeter of the office layout
have much more higher and neutral satisfaction levels compared to that of occupants on the core
region of the office layout.

Figure 164 Lighting satisfaction levels vs. Workspace /work station orientation

165

43. Acoustical condition satisfaction levels vs. Workspace /work station orientation.
Discussion:
The plotted chart shows us the lighting condition satisfaction levels vs. the workstation position,
from the chart we can understand that occupants located in both perimeter and core region of the
office layout have much higher and neutral satisfaction levels. Since Acoustical conditions does
not vary much with the location in an open plan office.

Figure 165 Acoustical condition satisfaction levels vs. Workspace /work station orientation

44. Air Quality satisfaction levels vs. Workspace /work station orientation.
Discussion:
The plotted chart shows us the air quality satisfaction levels vs. the workstation position, from
the chart we can understand that occupants located in the perimeter as well as core of the office
layout have more higher and neutral satisfaction levels.
166

Figure 166 Air Quality satisfaction levels vs. Workspace /work station orientation
45. Spatial condition satisfaction levels vs. Workspace /work station orientation.
Discussion:
The plotted chart shows us the spatial condition satisfaction levels vs. the workstation position;
from the chart we can understand that occupants located in the perimeter as well as core of the
office layout have more higher and neutral satisfaction levels. But in general occupants with
access to views, windows and other perimeter workstation location attributes are more satisfied
than the occupants located in the core of the offices layout.

Figure 167 Spatial condition satisfaction levels vs. Workspace /work station orientation

167

46.Lighting conditions Satisfaction levels of users vs. Orientation of the building
Discussion:
Figure x shows the results by plotting the individual occupants lighting condition satisfaction
levels versus the buildings orientation. The plotted chart shows that occupants who belong to
buildings that are oriented towards the Northeast seem more satisfied with the lighting
conditions since the curve is skewed towards the right.
The sample of Occupants who belong to the southwest seems to be on a neutral or higher
satisfaction levels.

Figure 168 Lighting conditions Satisfaction levels of users vs. Orientation of the building Figure 169 Lighting conditions
Satisfaction levels of users vs. Orientation of the building

47.IEQ satisfaction levels vs. orientation
Discussion:
Figure x shows the results by plotting the individual occupants IEQ satisfaction levels versus the
buildings orientation. The plotted chart shows that occupants who belong to buildings that are
oriented towards the Northeast seem satisfied with the lighting conditions since the curve is
skewed towards the right. Likewise the occupants from buildings that face southwest
Have a satisfied and a neutral opinion
168

Figure 170 IEQ satisfaction levels vs. orientation Figure 171 IEQ satisfaction levels vs. orientation
48.Air movement satisfaction level versus WWR
Discussion:
Todays buildings mostly have more than 20 – 30 % wwr , Solar heat gain through windows
affect the heat flow in a building, Air flow can reduce the heat that’s being treansmitted, hence
air movemnet is important to keep the work environment comfortable. The plotted chart shows
the window wal ratios of the building versus the air movement satisfaction levels. The p value is
0.0515, Hence the means are statistically significant we can arrive at a conclusion from the
plotted chart that higher percentages of WWR contributes to higher airmovent satisfaction
levels.

Figure 172 Air movement satisfaction level versus WWR
169

Analysis of Variance

Source DF Adj SS Adj MS F-Value P-Value
AIRMOVEMENT 6 3625.2461 604.207681 2.17 0.0515

Table 68 Air movement satisfaction level versus WWR

49.Temperature conditions satisfaction level versus WWR
Discussion:
The plotted chart shows the window wal ratios of the building versus the air movement
satisfaction levels. The p value is 0.3, Hence the means are not statistically significant we
cannot arrive at any conclusion from the plotted chart. However as discussed ablove the window
to wall ratio determines the heat flow in a bulinh and also the windows SHGC contributes
majorly to the temperature conditions of the indooer space since lower the SHGC, the lesser the
solar heat that is being trasmitted through the windows.

Figure 173 Temperature conditions satisfaction level versus WWR

Analysis of Variance

Source DF Adj SS Adj MS F-Value P-Value
TEMPERATURE CONDITIONS 6 2142.5810 357.096839 1.22 0.3004

Table 69 Temperature conditions satisfaction level versus WWR
170

50.Lighting condition satisfaction level versus WWR
Discussion:
The plotted chart shows the window wal ratios of the building versus the lighting condition
satisfaction levels. The p value is 0.6, Hence the means are not statistically significant we
cannot arrive at any conclusion from the plotted chart. However people prefer a minimum 20
percent to 30percent ratio of window area to wall area. Glazing the wall areas below desk height
(0-30 in. above the floor) offers little or no benefits for daylighting an office or view for the
occupants. (ASHRAE AEDG 2004).

Figure 174 Lighting condition satisfaction level versus WWR
Analysis of Variance

Source DF Adj SS Adj MS F-Value P-Value
LIGHTING CONDITIONS 6 1236.2343 206.039043 0.69 0.6613

Table 70 Lighting condition satisfaction level versus WWR

171

51.Temperature satisfaction levels vs. building façade color

By plotting the individual occupants temperature satisfaction levels versus the buildings facade
color in the chart below. The P value in ANOVA is very high; hence there is no significance in
the relationship of temperature satisfaction levels and the building facade color.

Figure 175 Temperature satisfaction levels vs. building façade color Figure 176 Temperature satisfaction levels vs. building
façade color
One way ANOVA Analysis of Variance

Source DF Adj SS Adj MS F-Value P-Value
Facade color 2 1.170167 0.58508349 0.36 0.7018

Table 71 Temperature satisfaction levels vs. building façade color

172

52.IEQ versus WWR
Discussion:
The results we obtain by plotting the individual IEQ satisfaction levels versus the buildings
WWR- South. The P value is 0.06; the plotted chart shows that the means are not marginally
statistically significant. There can be a marginal significance in the relationship between the
means of WWR south of the buildings and IEQ satisfaction levels of the occupants who
answered the survey questionnaire. A moderate (17) WWR in the south façade seems to have
more satisfaction IEQ levels

Analysis of Variance

Source DF P-Value
Regression 4 0.4028
WWR -
NORTH
1 0.8255
WWR -
SOUTH
1 0.0687
WWR-EAST 1 0.7119
WWR-WEST 1 0.8237

Table 72 IEQ versus WWR

Figure 177 IEQ versus WWR Figure 178 IEQ versus WWR

173

53. IEQ satisfaction VS VINTAGE of building
Discussion: Figure 179 shows the results by plotting the individual IEQ satisfaction levels versus
the buildings vintage or year built. This comparison is made in odder to see if there any changes
that age of the buildings cause the occupant to feel discomfort. The plotted chart shows that. The
oldest building, which is built in 1940, also seems to have high satisfaction levels. The recently
built that is 1998 has few dissatisfaction responses too

Figure 179 IEQ satisfaction levels VS VINTAGE of the building.

174

Chapter 7: Conclusion and future work
7.1 Conclusion and findings:
Offices spaces or work environments in an academic organization have a number of varieties in
the kind of spaces it has to provide to each task and situation in the academic community.
During this research project various kinds of academic workspaces were studied namely single
occupancy cellular spaces open type office spaces, multi occupancy cellular spaces. These
workspaces are changing, since the space demands too keeps changing. The occupant
satisfaction questionnaire is not a direct reflection of the quality of the IEQ conditions or the
functionality of the work environment but it can be understood as the expectations of the
occupant’s comfort levels. Hence the findings are not a solution to the current spatial or IEQ
condition but might be considered as an aid while making changes or renovations to the spaces.

7.1.1 Measured data using hand held sensors:

AIR VELOCITY-
• 3.85% of the sample workspaces are observed to be above the ASHRAE 55 standards
and 96.15% are within the ASHRAE 55 standards of permissible air velocity.
INDOOR AIR TEMPERATURES-
• The indoor air temperatures are satisfying the ASHRAE 55 standards. I.e. within 20
degree Celsius and 26 degree Celsius
CO2 LEVELS-
• The measured CO2 levels mostly fall within the standards of EPA (IAQ spec.).
175

• 16.92 % is observed to be above the EPA (IAQ spec.) standards and 83.08 %within the
EPA (IAQ spec.) standards of permissible CO2 levels
LIGHTING –
• More than 50% of measured primary work surface lux and Reading or keyboard area
lighting levels does fall within the standards of IESNA RP-1-04 office Lighting Guide
(2004)
• Although few workstations were observed to have light levels above the 500 lux IESNA
RP-1-04 office Lighting Guide (2004) standards of permissible lighting levels for
primary work surface/reading area lux and a very small number of workstation lighting
levels were below 200 IESNA RP-1-04 office Lighting Guide (2004) standards of
permissible lighting levels for both primary work surface and reading area zone.
• However the measured screen surface lux lighting levels were mostly observed higher
than the standards of IESNA RP-1-04 office Lighting Guide (2004)

ACOUSTIC CONDITION
• The acoustic component of an office space defines by ASHRAE (2001) is that the
acoustic decibel levels should be lesser than or = 40 dBA for an open plan offices space.
And the acoustic decibel for private office space should not be more than 35 dBA
• It is observed that the readings taken at buildings are much higher compared to the given
standards.

176

Unified Glare Ratio
• The UGR (unified glare ratio) should be lesser than or equal to 19 according to the CIE
standards. The calculated UGR with the help of the fish eye lenses and PHOTOLUX
software mostly complies with the standards.

7.1.2 Environmental quality analysis survey questionnaire findings
(summary)

Offices spaces or work environments in an academic organization have a number of varieties in
the kind of spaces it has to provide to each task and situation in the academic community.
During this research project various kinds of academic workspaces were studied namely single
occupancy cellular spaces open type office spaces, multi occupancy cellular spaces. These
workspaces are changing, since the space demands too keeps changing. The occupant
satisfaction questionnaire is not a direct reflection of the quality of the IEQ conditions or the
functionality of the work environment but it can be understood as the expectations of the
occupant’s comfort levels. Hence the findings are not a solution to the current spatial or IEQ
condition but might be considered as an aid while making changes or renovations to the spaces.

177

Demographic data

• The sample size consisted of almost equal size samples of men and women belonging to
different age groups and job category.
• The largest sample belonged to the age group 18-29 and 51 % of the survey sample were
students. The occupants had varied work experiences with the institution. 42 % had less
than one-year work experience.
• The job satisfaction levels were mostly satisfied find and neutral.

Office physical setting layout
Spatial quality-
• The sample occupants overall seemed to be satisfied with present conditions, since 62 %
of the occupants answered they were satisfied with the overall building / office layout.
• More than 50% of the sample answered that they were satisfied with the size of their
work space/area and the distance between their workstation.
• More than 50 % seem to be happy with the colors and textures of flooring, furniture and
surface finishes

Privacy level:
• More than 50 % of the sample size was satisfied with their privacy levels.
• However 19 % of the sample size was unhappy with their degree of enclosure.
• 33% were unsatisfied with the ability alter the physical conditions.
178

• 28 % of the sample was not happy with the ability to access outside view from their
workspace.
• 40 % of the sample size was unhappy with the ability to control their thermostats.

IEQ components-
Temperature
• More than 70 % of the sample size have answered that they are satisfied with the present
temperature condition
• 19 % are not very happy with ambient temperature levels at their workspace.

Air Quality /Air movement -
• 52 % of the sample size answered they were satisfied with the air quality
• Lighting, however 36% of the sample size answered they were not too satisfied with air
movement at their workspace.

Acoustic Quality /condition -
• 9 % of the occupants were unhappy with the amount of noise that been caused by peoples
conversation and
• 26 % of the occupants seemed to have disturbance due to background noises.

179

Lighting
• More than 60 % of the occupants answered they were satisfied with the quality of
lighting
• However 22 % were unsatisfied with the reflected glare on the computer screen and 19 %
answered they were unsatisfied with the glare caused due to daylight.

IEQ satisfaction Levels as whole-
• The final question was asked to get an idea from the occupants as to what they think
about the indoor environmental quality of the space. 2% of the sample answered that they
were very unsatisfied and 23 % of the occupants in the collected sample were satisfied,
and 7% of them were very satisfied 28 % were mildly satisfied and 26 % had a neutral
opinion.

7.1.3 Findings using MINITAB Express Analysis Software:

The IEQ satisfaction levels of the occupant could be subjected to gender, age, ethnicity, BMI and
other hidden human factors. Though the survey results were very integrative there were some
significant relationships that could be established. Following is the summary of significant
relationships that was deciphered.

180

7.1.3.1 Occupant feedback survey data vs. measured data using
hand held sensors significant findings:

• 96.15% of the measured air velocities of the workstation are within the ASHRAE 55
standards of permissible air velocity. (Lesser than or = 50 ft./min) By plotting the
individual Air movement comfort levels of the occupants versus measured air velocity
(ft./min) of their respective workspaces we can establish the relation that Higher
satisfaction with air movement contribute to higher IAQ satisfaction. A certain level of
air movement seems to contribute to occupants’ IAQ satisfaction. Installing operable
windows might help the occupants control the amount of air movement that comforts
them

• Glare is a major issue; especially if there is glare on the computer screen it makes it
really difficult to work. The measured screen monitor surface lux lighting levels are
mostly higher standards of IESNA RP-1-04 office Lighting Guide (2004) by plotting the
individual glare caused due to computer screen (comfort levels) of the occupants versus
measured computer screen (lux) of their respective workspaces we can conclude there is
marginal statistical significance in the relationship between the measured screen lux and
amount of glare on computer screen and their comfort levels that has been collected
through the occupant feedback survey. As the screen lux increases the satisfaction levels
of glare from computer screen lux also increases. Hence we can say that the occupants in
prefer a moderate to Screen brightness level in odder to eliminate glare caused by the
computer screen.

181

• The permissible levels of CO2 should be 1000 ppm, The measured CO2 levels mostly
fall within the standards of EPA (IAQ spec.) and ASHRAE 62 (2004) by plotting the
individual Air Quality comfort levels of the occupants versus measured CO2 levels
(ppm) of their respective workspaces.it is possible to establish a relationship between the
measured CO2 and IEQ comfort levels. There is increased satisfaction levels with 700
ppm -1000 ppm of co2 and IEQ dissatisfaction levels at 1250 ppm of co2 levels.7.1.3.2

Occupant
feedback
survey
data
vs.
occupant
feedback
survey
significant
findings

• By plotting the individual IEQ (comfort levels) of the occupants versus their respective
age groups. Its found that there is marginal statistical significance in the relationship
between the age groups and the IEQ satisfaction levels Age group 50- 59 have the most
IEQ satisfaction level and age group 40-49 have the least IEQ satisfaction level.

• By plotting the individual satisfaction levels of the occupants lighting conditions for their
computer based task versus satisfaction levels of glare caused due to their computer
screen. Higher satisfaction with lighting conditions contributes to higher satisfaction with
glare due to screen satisfaction levels.

• By plotting the individual satisfaction levels of glare caused due light fixtures versus
satisfaction levels of glare caused due to Daylight. The plotted chart tells us higher
satisfaction with glare caused due light fixtures contributes to higher satisfaction in glare
levels caused due to daylight.

182

• By plotting the individual satisfaction levels of the occupant’s privacy level versus
satisfaction levels of general office layout. The plotted chart shows that higher
dissatisfaction levels of privacy conditions contribute to higher dissatisfaction of general
office layout.

• By plotting the individual satisfaction levels of the occupant’s satisfaction levels in terms
of distance between their workstations versus satisfaction levels of general office layout.
It can be understood that higher the dissatisfaction levels of distance between their
workstations contributes to higher dissatisfaction levels of the office layout.

• By plotting the individual satisfaction levels of noise caused due to conversation (office
chatter) versus occupant’s satisfaction levels of noise caused due to background noise
such as mechanical systems etc. It can be understood that higher the dissatisfaction levels
of noise caused due to conversation (office chatter) contributes to higher dissatisfaction
levels of noise caused due to background noise such as mechanical systems etc.

• By plotting the individual satisfaction levels of the occupant’s air movement satisfaction
levels versus satisfaction levels of Indoor air quality, it can be understood that higher
satisfaction with air movement contributes to higher IAQ satisfaction. A certain level of
air movement seems to contribute to occupants’ IAQ satisfaction.

183

• By plotting the individual occupant satisfaction levels of Indoor air quality versus
occupant’s satisfaction levels of IEQ. It can be understood that higher the dissatisfaction
levels of air quality contributes to higher dissatisfaction levels of Indoor environmental
quality.

• By plotting the individual occupant satisfaction levels of Indoor air movement versus
occupant’s satisfaction levels of IEQ it’s found that higher satisfaction with air
movement contributes to higher IEQ satisfaction.

• By plotting the individual occupant satisfaction levels of lighting condition versus
occupant’s satisfaction levels of IEQ. It can be understood that higher satisfaction levels
of lighting condition contributes to higher satisfaction levels of Indoor environmental
quality

• By plotting the individual occupant satisfaction levels of office layout i.e. spatial quality
versus occupant’s satisfaction levels of IEQ. It can be understood that higher satisfaction
levels of spatial Quality contributes to higher satisfaction levels of Indoor environmental
quality

• By plotting the individual occupant satisfaction levels of controllability of thermostats
versus occupant’s satisfaction levels of IEQ It can be understood that higher satisfaction
levels of thermostat controllability contributes to higher satisfaction levels of Indoor
environmental quality
184

• By plotting the individual occupant satisfaction levels of distance between their
workstations versus occupant’s satisfaction levels of IEQ. It can be understood that
higher satisfaction levels of distance between their workstation/work area contributes to
higher satisfaction levels of Indoor environmental quality.

• By plotting the individual occupant satisfaction levels for light for their computer based
tasks versus occupant’s satisfaction levels of IEQ. It can be understood that higher
satisfaction levels of light for their computer based tasks contributes to higher
satisfaction levels of Indoor environmental quality.

• By plotting the individual occupant satisfaction levels for direct glare caused due to light
fixtures versus occupant’s satisfaction levels of IEQ. It can be understood that higher
satisfaction for direct glare caused due to light fixtures contributes to higher satisfaction
levels of Indoor environmental quality

• By performing ANOVA with IEQ satisfaction levels and the factors that influence IEQ
majorly, it is evident that there are significant p values and hence a relationship between
the factors namely Air quality, Air movement, Lighting and Spatial quality which have p
values lesser than 0.05 in ANOVA and Indoor environmental Quality can be established.
The satisfaction levels of the factors contribute to the overall satisfaction levels of IEQ.

185

7.1.3.3 Occupant feedback survey vs. physical setting significant
findings

• By plotting the individual occupants work station position that was recorded versus
occupant’s satisfaction levels access to outside views. It can be derived that higher
satisfaction levels for the question access to outside views prevails among the occupants
who have their workstations located in the perimeter of the office layout.

• By plotting the individual IEQ satisfaction levels versus the buildings WWR- South.
There can be a marginal significance in the relationship between the means of WWR
south of the buildings and IEQ satisfaction levels of the occupants who answered the
survey questionnaire. A moderate (17) WWR in the south façade seems to have more
satisfaction IEQ levels.

7.2 Future work
• The results from the questionnaires were very integrative yet there were some significant
findings by analyzing the data. More conducive results from the questionnaire would
have given a better picture of the satisfaction levels of people; Learning more about how
a user-friendly questionnaire can be prepared might help to strengthen the survey and
obtain more optimum results from the survey participants.

186

• Continuous measurement of Temperature data through data loggers might have helped
the research in Oder to draw better conclusions. Hence, learning how to use such data
loggers like the HOBO will help conducts the data collection process to be in a more
organized manner.

• The EBOT that was used in the research as an experimental attempt, This study helped to
identify the errors and modify the design of the environmental cart, hence more such
experimentation with the cart would provide a platform to modify the cart to produce
accurate/better measurements.

• Keeping the significant findings in mind, recommending few design changes in the
buildings where measurement and questionnaires were given might help to provide the
building users with a better work environment.

187

Bibliography

J. Heerwagen Healthy Buildings: A Proposal for a Research Initiative on Health and
Indoor Environments, University of Washington, Seattle (2010)

Singh J. Review: health, comfort, and productivity in the indoor environment.Indoor Built
Environ. 1996;5(1):22–33

How IEQ Affects Health, Productivity T By William J. Fisk, P.E., Member ASHRAE 2002

V. Loftness, V. Hartkopf, L.K. Poh, J. Choi, M. Snyder, Sustainability health are integrated goals
for the built environment, in: Proceedings of Healthy Buildings, vol. 1, Lisbon, Portugal, 2006,
pp. 1–17

Workspace satisfaction: The privacy-communication trade-off in open-plan offices Jungsoo
Kim*, Richard de Dearournal of Environmental Psychology 36 (2013)

Learning from Our Buildings: A State-of-the-Practice Summary of Post-Occupancy
Evaluation .2 The Evolution of Post-Occupancy Evaluation: Toward Building Performance and
Universal Design Evaluation by Wolfgang F.E. Preiser, Ph.D. 1999

Organisation for Economic Co-operation and Development 1997 The OECD Report on
Regulatory Reform: Synthesis, Paris.

Preiser, W. F. E. (1995) ‘Post-occupancy evaluation: How to make buildings work better’,
Facilities

Vischer, J. (2005), Revaluing Construction: Building Users’ Perspective. Montreal,
Quebec,Canada: School of Industrial Design, Univ. of Montreal

Wener, R. (1989). Advances in evaluation of the built environment.In E. Zube & G. Moore
(Eds.). Advances inenvironment, behavior and design. Vol. 2. pp. 287-313.New York: Plenum.

postoccupancyevaluation.com/results.shtml 2011

CABE. 2011. "Post-occupancy evaluation | Sustainable Places" Accessed March 22 2011
http://webarchive.nationalarchives.gov.uk/20110118095356/http:/www.cabe.org.uk/sustainable-
places/advice/post-occupancy-evaluation

Gossauer,E A W(2005) user satisfaction at workspaces: A study in 12 office Buildings in
Germany , CISBAT,Lausanne Switzerland

The Efficient Windows Collaborative Tools for Schools 2011 Regents of the University of
Minnesota, Twin Cities Campus, Center or Sustainable Building Research, efficientwindows.org
188

The impact of façade designs: orientations, window to wall ratios and shading devices on indoor
environment for naturally ventilated residential buildings in Singapore by Wang Liping and
Wong Nyuk Hien, Department of Building, National University of Singapore, Singapore.
PLEA2006 - The 23rd Conference on Passive and Low Energy Architecture, Geneva,
Switzerland, 6-8 September 2006

The Centre for Sustainable Buildings and Construction, Building and Construction Authority.
2010 Building and Construction Authority,
Singapore.,http://www.bca.gov.sg/GreenMark/others/bldgplanningmassing.pdf

The development of the New Jersey Green Building Manual 2011
2AWWRhttps://static.squarespace.com/static/5386a690e4b017042145f34e/t/53a5ff90e4b0075a5
9f4b448/1403387792746/architecture-at-zero_window-to-wall_updated.pdf

Bioclimatic Principles in Architectural Design: a Way to Better Buildings by prof. habil.
dr. Jurgis VanagasThe Vol. 5 , http://ar.vgtu.lt/fakultetai/padaliniai/urbanistikos-katedra/kita-
informacija/52098

Air Movement and Control Association International, Inc 2015 http://www.amca.org/
Novieto D.T. and Zhang Y. 2010. Therm. Comf. Impl. of the Aging Eff. on Metabol., Card. Out.
and Body Weight. Proc.: Adapt. to Change: New Thinking on Comf., Windsor (UK)

Seppänen OA, Fisk WJ, Mendell MJ. (1999) Association of ventilation rates and CO -
concentrations with health and other responses in commercial and institutional buildings. Indoor
Air J, 9, 252-274

Wargocki P, Wyon DP, Sundell J. (2000) The effects of outdoor air supply rate in an office on
perceived air quality, sick building syndrome (SBS): symptoms and productivity. Indoor Air
J,10, 222-236.

Wargocki P, Wyon DP, Fanger PO. (2004) The performance and subjective responses of
callcenter operators with new and used supply air filters at two outdoor air supply rates. Indoor
Air J, 14, Suplement 8, 7-16.

Milton, D.K.., Glencross, P.M., et al. (2000), “Risk of sick Leave Associated with Outdoor Air
Supply Rate, Humidification and Occupant Complaints”, Journal of Indoor Air , Vol. 10 No. 4,
pp. 212-221

View through a window may influence recovery from surgery. by Roger S. Ulrich April 27, 1984
American Association for the Advancement of Science. Due to publisher request, Science cannot
be reproduced until 360 days after the original publication date

USArmr Corps Engineers, Design Guide for Interiors 1997
189

ASHRAE Standard 55, Thermal Environmental Conditions for Human Occupancy, American
Society of Heating, Refrigerating, and Air-conditioning, Inc., Atlanta, 2010.

Developing an adaptive model of thermal comfort and preference e Dear, R.J., and G.S. Brager,
1998. Towards an adaptive model of thermal comfort and preference. ASHRAE Transactions,
Vol 104 (1), pp. 145-167.

Fanger, P. O. (1970). Thermal Comfort. Copenhagen: Danish Technical Press.

Sun, R. (1986). Evaluating the Use of a 1:12 ScaleModel in Predicting Daylight Distribution in a
Room,Master Thesis, University of Florida.

Attia, S., Gratia, E., De Herde, A (2011) Achieving informed decision-making for net zero
energy buildings design using building performance simulation tools, International Journal of
Building Simulation, Tsinghua-Springer Press, Vol 6-1, P 3-21, 10.1007/s12273-013-0105-z.

GLOSSARY DEFINITION FOR DATA-ACQUISITION-SYSTEM Glossary Term: Data-
Acquisition-System
http://www.maximintegrated.com/en/glossary/definitions.mvp/term/Data-Acquisition-
System/gpk/74

Sundstrom E., Town JP., Rice RW., Osborn DP. and Brill M. Office noise, satisfaction and
performance,
Environment and Behavior, Vol 26, No. 2, 195-222, March 1994

L. Zagreus, C. Huizenga, E. Arens, and D. Lehrer. Listening to the Occupants: A Web-based
Indoor Environmental Quality Survey. Indoor Air 2004. 14 (Suppl 8) (December 2004) 65–74.

Asset Metadata

Creator Raman, Varshini (author)

Core Title Impacts of indoor environmental quality on occupants environmental comfort: a post occupancy evaluation study

Contributor Electronically uploaded by the author (provenance)

School School of Architecture

Degree Master of Building Science

Degree Program Building Science

Publication Date 07/31/2015

Defense Date 05/01/2015

Publisher University of Southern California (original), University of Southern California. Libraries (digital)

Tag Building design,environmental comfort,environmental quality standards,indoor environmental quality,OAI-PMH Harvest,occupant comfort,post-occupancy evaluation,Sustainable Design

Format application/pdf (imt)

Language English

Advisor Choi, Joon-Ho (committee chair), Konis, Kyle (committee member), Noble, Douglas (committee member)

Creator Email varshiniraman@gmail.com,varshinr@usc.edu

Permanent Link (DOI) https://doi.org/10.25549/usctheses-c3-621700

Unique identifier UC11303844

Identifier etd-RamanVarsh-3764.pdf (filename),usctheses-c3-621700 (legacy record id)

Legacy Identifier etd-RamanVarsh-3764.pdf

Dmrecord 621700

Document Type Thesis

Format application/pdf (imt)

Rights Raman, Varshini

Type texts

Source University of Southern California (contributing entity), University of Southern California Dissertations and Theses (collection)

Access Conditions The author retains rights to his/her dissertation, thesis or other graduate work according to U.S. copyright law. Electronic access is being provided by the USC Libraries in agreement with the a...

Repository Name University of Southern California Digital Library

Repository Location USC Digital Library, University of Southern California, University Park Campus MC 2810, 3434 South Grand Avenue, 2nd Floor, Los Angeles, California 90089-2810, USA

Abstract (if available)

Abstract A research methodology applying Post Occupancy Evaluation (POE) as a platform that systematically studies and focuses on indoor environmental quality of an occupied building may help understand and provide lessons to improve their current conditions and also provide guidance to future building designs. In spite of significant design efforts for enhancing building indoor environmental quality (IEQ) conditions, there have been many complaints reported from modern work environments, such as thermal discomfort, glare, and poor air/acoustic condition perceived in a workplace. It may be because of current guidelines developed without much knowledge about modern technology-intensive work environment, which may be different from the condition assumed in the current standards or guidelines. A comprehensive post-occupancy evaluation studies can help understand the current changes that are required in order to improve occupant environmental satisfactions and IEQ conditions by investigating the relationships between building design/ system features, occupants’ physiological characteristics, and their ambient IEQ conditions. ❧ New buildings are required to meet increasingly demanding standards with respect to occupant comfort, cost effectiveness and sustainability, while still allowing the designer to aesthetic and design freedom. And this could be achieved through understanding historical and futuristic approaches of building design and user satisfaction. Keeping in mind sustainability is not only restricted to energy conservation and also extends itself occupant comfort, IEQ conditions and user feedbacks on IEQ becomes most important criteria in a buildings sustainable design, one has to implement POE in building process and maintenance.