Comfort Level Survey

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Planning Department: Urban Climatic Map and Standards for Wind Environment Feasibility Study

TECHNICAL INPUT REPORT No. 1

Urban Climatic Map and Standards forWind Environment - Feasibility Study

Technical Input Report No.1:

Methodologies and Findings of Users

Wind Comfort Level Survey

Nov 2008

C U H K


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VERSIONS

3 Dec 2007 First circulated version (v2) to PlanD and SG.

Comments received on 27 Feb 08. Responds to

Comments made on 17 Mar 08.

30 Jun 2008 Revised version (v9) submitted to PlanD.

17 Sept 2008 Revised version 11d. HKOs comments have been

incorporated.

4 Nov 2008 Revised and submitted to PlanD with comments

responded on 4 Nov 08.

File name: User_survey_v13_04Nov08.doc printed 13/01/2009 17:24:00

Department of Architecture, CUHK Page 1 of 150


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EXECUTIVE SUMMARY

1) Urban outdoor thermal comfort is important for people using outdoor spaces. The main objectives of the

Users Wind Comfort Level Survey are i) to understand the outdoor thermal comfort requirements of Hong

Kong people and ii) to find out the range of comfortable wind environment required by them.

2) The methodology of the Users Wind Comfort Level Survey include: i) micro-meteorological measurement

and ii) user questionnaire survey. The data were collected throughout 2006-2007 to capture a wide range

of weather conditions of Hong Kong. 2702 interviews have been completed.

3) In line with international practice, the Physiological Equivalent Temperature (PET) comfort model is used to

analysis the results. The model allows a synergetic understanding of human thermal comfort based on

various environmental and physiological inputs, like air temperature, radiation, humidity, clothing, and so on.The PET value that one expresses a neutral (neither cool nor warm) thermal sensation (nTS) is known as

the neutral PET (nPET).

4) The summer months are considered more critical for urban thermal comfort in Hong Kong, the summer

dataset is a key focus of analysis. The Hong Kong Observatory (HKO) long-term air temperature data

have been used to establish the nPET under typical HK summer condition. Based on the survey, it is

established that the summer mean nPET is 28.1, and about 50% of the surveyed subjects would

express nTS when PET is in the range of 27-29

; 32% will express thermal sensation of too warm, 13%hot and 4% very hot. For the summer nPET = 28.1, for example, under an air temperature of

27.9, relative humidity of 80%, and a person standing or walking under shade on streets or in urban

spaces, in the summer months, a light breeze of 0.53-1.30 m/s would be thermally comfortable .

5) Due to thermal adaptation, the winter nPET is lower, at 14.6 under HK typical winter conditions. About

70% of the surveyed subjects would express nTS when PET is in the range of 14-16 . Even at PET of

13 or lower, only 42% of the surveyed subjects express TS=-1 or lower. For Hong Kongs typical

mean winter air temperature of 16.3, assume mean radiant temperature (Tmrt) of 17 (in shade), wind

speed needs to exceed 3 m/s to result in PET of 13 or lower. Except forexposed conditions, in very

windy days, thermal discomfort due to wind in the winter months is unlikely to be an issue.

6) For urban air ventilation, the survey results suggest that providing a light breeze in summer is important

and beneficial for the hot summer months of Hong Kong. It is important that the city is planned to optimise

air ventilation. Apart from air ventilation, to further improve urban thermal comfort, it is useful: i) to

provide more shaded areas in the city and ii) to provide greeneries, such as planting more trees.

They help to reduce solar radiation gain and lower air temperature.



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CONTENTS

EXECUTIVE SUMMARY 2

1 INTRODUCTION 5

2 BACKGROUND 6

3 METHODOLOGY 7

3.1 Micro-meteorological Measurement 8

3.2 User Questionnaire Survey 10

3.2.1 Site Selection 10

3.2.2 Sample Size 10

3.2.3 Survey Sampling 11

3.2.4 Survey Subject 11

3.2.5 Survey Questionnaire 12

3.2.6 Survey Procedure 15

3.2.7 Programme of Survey 17

3.3 Data Analysis 20

3.3.1 Data Organization 203.3.2 Methods of Analysis 21

4 SURVEY FINDINGS 23

4.1 Results Based on Summer Data, Summer Non-A/C Data, and

Winter Data 23

4.2 Further Analysis of Typical Summer and Winter Conditions

in Hong Kong Based on HKO Data 24

4.3 Establishment of Wind Requirement Using Neutral PET Value

for the Summer 25

4.4 Wind and Thermal Comfort in the Winter Months 26

4.5 Various Environmental Conditions for Summer nPET=28.1 27

5 CONCLUSION 27

6 POSTSCRIPT 29

7 REFERENCES 29



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8 APPENDICES 33

Appendix 1 Details of Measuring Equipment 33

Appendix 2 Questionnaire for Users Wind Comfort Level Study 35

Appendix 3 Charts Showing Relationships between PET and TS 39

Appendix 4 Frequency Charts Showing Relationships between

Air Temp, Wind Speed and TS 45

Appendix 5 Maps of Summer User Survey Locations in Chronological

Order 46

Appendix 6 HKO Long-Term Monthly Air Temperature

Data 119

Appendix 7 Look-up Table Showing % of Subjects with nTS and

Corresponding nPET Range 120

Appendix 8 PET Look-up Table 121

Appendix 9 TS-PET Relationship under Typical Hong Kong Summer and

Winter Conditions 127

Appendix 10 Various Environmental Conditions for Summer

nPET=28.1 degree C 128

Appendix 11 Physiologically Equivalent Temperature as Indicator for

Impacts of Climate Change on Thermal Comfort of

Humans 129Appendix 12 PET Programme Code in Fortran 132

Appendix 13 Further Statistical Understanding 146

Appendix 14 Further Understanding of the Logistic Regression

Simulation 147

Appendix 15 Climatic requirements when neutral PET=28.5 150

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1 INTRODUCTION

Outdoor climatic conditions have great influences on thermal comfort sensation of people

outdoors and may therefore affect people using outdoor urban spaces such as streets, plazas,

playgrounds, urban parks and so on. For instance, thermal discomfort may be resulted

when people are exposed to the sun and high temperature in the hot summer time and the

uncomfortable feeling may discourage them from using open area like urban park. Thus, the

provision of comfortable outdoor conditions is crucial in promoting the use of outdoor

urban spaces.

The outdoor thermal comfort sensation of people depends on the particular combination of

air temperature, wind speed, solar radiation and relative humidity. Concerning wind, in

accordance with a thermal comfort study conducted under a hot and humid summer in

Thailand, the provision of air flow can effectively improve the thermal comfort sensation of

people. It indicated that an appropriate wind environment can help to alleviate the heat

stress in the hot summer time (Givoni et al., 2004, Khedari et al., 2000).

Stage A of Feasibility Study for Establishment of Air Ventilation Assessment System

(AVAS Study) in 2005 opined that a mean wind speed of 1.5 m/s 50% of the time can

provide a desirable and comfortable environment during summer months in Hong Kong

when pedestrians are walking under shade. This understanding is an approximation, and isbased on researches conducted in similar tropical environments elsewhere with theoretical

calculations (Cheng and Ng, 2006). In order to establish an eventual benchmark and

standard for Hong Kong, it is necessary to confirm the information obtained based on

observations of local people and climate.

The Users Wind Comfort Level Survey will address this issue. In the assignment brief,

the details of the survey, including the survey coverage, methodology, questionnaire, survey

findings and thermal comfort requirements for Hong Kong people, will be elaborated in this

report. The primary objectives of the user survey are: i) to understand the outdoor thermal

comfort requirements of Hong Kong people and ii) to find out the range of comfortable

wind environment required by them. The findings of the survey will serve as a basis for

setting the eventual air ventilation assessment standard, so that the expectation and

aspiration of Hong Kong people on wind environment could be reasonably addressed.



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2 BACKGROUND

The issue of outdoor thermal comfort has attracted wide attention in recent years; a large

amount of research has been conducted to understand the thermal sensation of people in

different outdoor spaces; under different climatic conditions; and with different adaptive

behaviours. A couple of research reviews have been done in the field of outdoor thermal

comfort. This section highlighted a comprehensive outdoor comfort study known as

RUROS (Rediscovering the Urban Realm and Open Spaces) conducted in Europe as a

funded project under the European Unions Fifth Framework Programme for Research (Key

Action 4: City of Tomorrow and Cultural Heritage) (Nikolopoulou and Lykoudis, 2006).

The methodology set out in the RUROS project serves as a basis for the current users wind

comfort study and thus, its sample size and methodology are consistent with the

international standard of other thermal comfort surveys carried out around the world, such

as the RUROS project.

According to the preceding outdoor thermal comfort researches conducted in different

places, air temperature, wind speed and relative humidity have been identified as the most

crucial factors which affect the thermal sensation of people indoor. Based on ASHRAE

Standard 55-2004: Thermal Environmental Conditions for Human Occupancy, these

environmental factors are essential and must be addressed when defining conditions for

thermal comfort (ASHRAE, 2004). Solar radiation intensity, which is not included inindoor thermal comfort prediction, has been found extremely influential in outdoor thermal

comfort issue (Givoni et al., 2003, Nagara, 1996).

Apart from the subjective questionnaire survey, the immediate microclimatic conditions in

which the interviewees exposed to were also monitored during the survey. The

microclimatic factors measured include air temperature, solar radiation, wind speed and

relative humidity. The measurements were conducted using a portable mini weather

station as shown in Figure 1.

Figure 1: Portable mini weather station used in RUROS project



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The physical environmental conditions obtained through the objective measurements were

later correlated with the subjective thermal comfort evaluation provided by the interviewees.

This analysis enabled the understanding of peoples subjective feeling towards different

outdoor climatic conditions. The readers may refer to further details of the thermal

comfort study under the context of the RUROS project by visiting its project website

http://alpha.cres.gr/ruros/.

The RUROS project serves as an exemplar for succeeding outdoor comfort studies. The

ASCCUE (Adaptation Strategies for Climate Change in the Urban Environment) project

funded by the UK Engineering and Physical Sciences Research Council has adopted the

RUROS methodology for studying the outdoor comfort conditions in Manchester and

Lewes, UK (Nicol et al., 2006). Besides, several other outdoor comfort studies conducted

in different parts of the world have also applied similar methodology in acquiring thermal

comfort data (Ahmed, 2003, Spagnolo and de Dear, 2003, Stathopoulos et al., 2004,

Thorsson et al., 2004). The current users wind comfort study largely adopts the RUROS

methodology but the questionnaire is modified in order to suit the unique context of urban

Hong Kong. The next section presents the details of the methodology employed in the

current users wind comfort study.

3 METHODOLOGY

The methodology employed in the current users wind comfort survey has an international

standing in the field of thermal comfort study; it has been widely adopted in outdoor

thermal comfort researches all over the world, e.g. the RUROS project (Nikolopoulou and

Lykoudis, 2006, Ramos and Steemers, 2003). Richard de Dear, a thermal comfort expert

who was one of the major contributors to the adaptive thermal comfort model set out in

ASHRAE Standard 55-2004: Thermal Environmental Conditions for Human Occupancy,

has applied this methodology in a study of outdoor thermal comfort in Sydney (Spagnolo

and de Dear, 2003). Besides, the methodology has also been applied in many other

outdoor thermal comfort studies conducted in different parts of the world (Ahmed, 2003,

Nicol et al., 2006, Spagnolo and de Dear, 2003, Stathopoulos et al., 1999, Stathopoulos et

al., 2004, Thorsson et al., 2004).

The methodology can basically be divided into two parts: i) micro-meteorological

measurement and ii) user questionnaire survey. The former includes physical measurement

of the microclimatic conditions at the immediate surrounding of the subjects. The latter

consists of questionnaire survey addressing the subjective thermal comfort data including

the subjects thermal sensation, comfort vote, record of subjects demographic background,



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and clothing and activities during the survey. Subjects thermal sensation and comfort

vote will be recorded by face-to-face interview while subjects demographic background,

clothing and activities will be recorded by observation. Eventually, the results of the

questionnaire survey will be correlated with the micro-meteorological data; this analysis

will provide understanding of peoples subjective feeling towards different outdoor climatic

conditions.

3.1 Micro-meteorological Measurement

Measurements of outdoor microclimatic conditions are made with mobile meteorological

station mounted on a camera tripod with spirit level as shown in Figure 2. All equipment

set-ups have been calibrated by the technicians before the survey. The design of this

mobile meteorological station has made reference to the meteorological devices used in

several preceding studies (Katzschner, 2003, Lindberg, 2004, Nicol et al., 2006, Ramos and

Steemers, 2003, Spagnolo and de Dear, 2003).

The meteorological station includes sensors for the measurement of air temperature (),

globe temperature (), wind speed (m/s), relative humidity (%) and solar radiation (W/m2).

These environmental factors have been identified to be the most influential in peoples

outdoor thermal comfort sensation (Givoni et al., 2003, Lindberg, 2004, Nagara, 1996,

Penwarden, 1973, Sasaki et al., 2000, Tacken, 1989).

Wind speed, air temperature and relative humidity are measured using TESTO 3-function

probe. A circular white disc made with polystyrene is placed above the opening on the

measurement probe where air temperature and relative humidity sensors are located; the

disc shaded these sensors from direct sun exposure.

Globe temperature is the temperature measured by a globe thermometer. In this study, the

globe thermometer used was tailor-made with reference to preceding studies to improve its

response time (Humphreys, 1977, Nikolopoulou et al., 1999). The thermometer basically

consists of a thermocouple wire held at the middle of a 38mm diameter black table tennis

ball. The temperature assumed by the globe at equilibrium results from a balance between

heat gain and lost by radiation and convection. The globe temperature is a component for

calculating the mean radiant temperature (Tmrt), which is one of the microclimatic elements

to predict the thermal comfort of people. Tmrt is calculated from the globe temperature via

the following equation (ASHRAE, 2004):



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( ) ( ) 273*

*10*10.1273

41

4.0

6.084

++= aggmrt tt

D

VtT

Where is emissivity (0.95 for a black globe),

D is globe diameter,

Vis ai speed in m s-1

,

Ta is air temperature in deg Celsius and tg is glove thermometers temperature in

deg Celsius.

TESTO flexible Teflon Type K thermocouple is used for the globe temperature

measurement. The air temperature, globe temperature, relative humidity and wind speed

sensors are connected to a TESTO 400 data logger with 5 seconds sampling and logging

time.

In addition to the TESTO sensors, another set of air temperature and relative humidity

sensors with a tailor-made sun shade are also installed for the purpose of cross checking.

This set of measurement includes a HOBO high-accuracy temperature sensor connected to a

HOBO H8 data logger with built in relative humidity sensor. The sampling and logging

time are set to 5 seconds and 1 minute respectively.

Solar radiation is measured using LICOR LI-200SA pyranometer connected to a LICOR

1400 data logger with 5 seconds sampling time. Figure 2 shows the setup of the mobile

meteorological station. Details of the sensors used in the measurement are listed in

Appendix 1. The timing systems inside the equipment are regularly synchronized with the

Hong Kong Observatorys timing system.

Figure 2: The mobile meteorological station



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3.2 User Questionnaire Survey

3.2.1 Site Selection

The primary objective of the user questionnaire survey is to obtain the subjective outdoor

thermal comfort sensation of local people in the urban environment of Hong Kong. The

site selection process aims to capture a wide range of environmental conditions. Under

this context, the survey sites are carefully selected based on parameters related to the

regional climatic conditions, topographic characteristics and urban morphology. The

parameters applied in this study include wind environment, ground coverage, street pattern,

building height and building density. Within a survey site, areas with different

microclimatic conditions (say shaded, unshaded, windy, wind-stagnant areas and so on) will

be chosen as study areas in the survey. Thus, the data obtained from the survey will

include a wide range of microclimatic conditions which people might encounter in urban

Hong Kong.

Apart from the microclimatic consideration, the survey locations are selected based on

different kinds of land uses and activities. Three types of site, i.e. street, estate and park,

have been selected. For the estate, private and public housing estates are included. Prior

permissions from the property management companies and Housing Authority will be

obtained before the survey is carried out in the selected estates. These categories take intoaccount the differences in nature of activities in the survey sites and the psychological

expectation of the people.

3.2.2 Sample Size

The assignment brief requires 1000 completed interviews to be obtained from the survey.

Similar survey design has been applied in many thermal comfort surveys. In the RUROS

project, the sample size for the surveys carried out in four out of seven cities was about

1000. These surveys were conducted in four seasons (Nikolopoulou and Lykoudis, 2006).

The survey conducted in Sydney by thermal comfort expert Richard de Dear had a sample

size of 1018, in which 585 and 433 interviews were conducted in summer and winter

respectively (Spagnolo and de Dear, 2003). The total sample size of Ahmeds study in

Bangladesh was about 1500 and all data were obtained in summer (Ahmed, 2003).

Therefore, the 1000 target sample size is in line with the international practice.



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3.2.3 Survey Sampling

Probability sampling is not adopted in this survey because the results are not inferred from

the whole population of Hong Kong. Also, there is no preceding thermal comfort study

conducted anywhere in the world that adopts probability sampling because it is known that

the population cannot be defined in this kind of survey. There are also several practical

reasons which make probability sampling not practically feasible to be carried out in this

study1. Instead, the study follows the general practice of urban thermal comfort study of

the research community to establish a physio-psychological relationship between thermal

sensation (TS) based on the Physiological Equivalent Temperature (PET) model.

3.2.4 Survey Subject

According to the guidelines for survey and behavioural research ethics of The Chinese

University of Hong Kong (The Chinese University of Hong Kong, 2000), in the case of

using normal secondary school children (i.e. form 1 and above) as research subjects, school

consent is deemed sufficient but parental consent is strongly recommended. Moreover, the

guidelines state that children (i.e. age below 18) should not be asked to serve as research

subjects if the required data could be obtained from adults. In view of this, the subject

targets of the survey are the outdoor general public at the age of 18 or above. Special

attention is paid on the gender and age composition so that gender and age biases could bereduced as far as possible.

1 First, it is not practically feasible to define the population of the survey and major predictor variables are controllable.

For example, the interviewers could know the gender and age of the interviewees. However, the probability of being

selected is unknown because the interviewers cannot predict or even count the exact number of passers-by who would pass

by the study site during the survey unless the site area is entirely sealed by the interviewers in advance. During the

survey, the interviewers would stop the passers-by haphazardly and ask them to answer the questionnaire. It is difficult

to establish a complete sampling list and randomly selecting sampling units could hardly be possible. Thus, respondents

are eventually selected with unknown probability. Apart from this, selecting respondents with a known probability from

passers-by at specific site could be laborious and costly. When taking these considerations into account, it is not necessary

to attempt probability sampling. Even though probability sampling is not attempted, the objective of the survey as

mentioned above could still be attained and the results could be inferred to the intended scope of the survey.

Second, in terms of resources, probability sampling could be achieved provided that extra resources could be reached, say

more provision of interviewers and funding. This is because probability selection of areas and individuals are very

expensive, and extra costs in terms of time, money, human resources and so on would be required.

At last, as mentioned above, time would be one of the extra costs if random sampling was attempted. Usually, survey with

probability sample needs longer time to be finished. Therefore, if the survey sample was random, the Study would not befinished on time and within three years. In that situation, longer completion time, together with extra funding and human

resources, would be needed.



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3.2.5 Survey Questionnaire

Subjective thermal comfort data is recorded using a questionnaire adapted from several

preceding studies (de Dear et al., 1997, Stathopoulos et al., 2004) with special reference to

the one used in the RUROS project (Nikolopoulou and Lykoudis, 2006) and the ASHRAE

standard questionnaire for indoor thermal comfort study (ASHRAE, 2004). These

questionnaires have been developed through a series of pilot investigation.

The questionnaire being used in the current wind comfort survey is attached in Appendix 2.

The questionnaire is divided into two parts. Part A addresses the immediately past thermal

experience of the subjects and their subjective sensation of the corresponding microclimatic

conditions. Most of the questions were adapted from the preceding studies although the

options for the answers might be slightly different. The questions in Part A are as follows:

1. Question Have you done this questionnaire before?

Answer Yes/ No (If the answer is Yes, the interview will be terminated.)

Reason Ensure the subject is not repeat sampled

2. Question Have you been staying in Hong Kong in the past 6 months?

Answer Yes/ No

Reason To understand the subjects long-term acclimatization

3. Question In the past 15 minutes, have you been to (or stayed in) indoor spaces with

air-conditioning or heating system (including bus, taxi, minibus, etc)?

Answer Yes / No

Reason To understand the subjects short-term acclimatization

4. Question What were you doing in the past 15 minutes?

Answer Waiting for people or cars / resting / standing / sitting / working /

grocery shopping / shopping / doing exercises/ others

Reason To understand the subjects immediately past experience

5. Question Why do you choose to sit/stand at this particular place?

(can choose more than one item)

Answer In shade / under tree-cover / under sunshine / breezy / fresh air/

views / have an appointment / no particular reason / going to

school or work/ close to home or office or school or station/

others



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Reason The reason for being in the place of interview

6. Question How do you feel in terms of thermal perception?

Answer Very Hot / Hot / Too warm / Neutral / Too cool / Cold / Very Cold

(7-point scale from +3 to -3 according to the ASHRAE thermal sensation scale)

Reason To understand the subjects thermal sensation

7. Question Is the interviewees head/ body exposed to the direct sunlight?

(observation by interviewer)

Answer Yes / No

Reason To understand if the subject is exposed to direct sun

8. Question How do you feel about the exposure to the sun?

Answer Sun makes me uncomfortable / Just right / Not enough, Id like to get more sun

(3-point scale from +1 to -1)

Reason To understand the subjects perception of the solar condition

9. Question How do you feel about the wind?

Answer Stagnant / Too still / Slightly still / Just right / Slightly windy /

Too windy / Much too windy (7-point scale from +3 to -3)

Reason To understand the subjects perception of the wind condition

10. Question How do you feel about the air, in terms of humidity?

Answer Too humid / Just right / Too dry (3-point scale from +1 to -1)

Reason To understand the subjects perception of air humidity

11. Question How is your skin, in terms of wetness?

Answer Drops of sweat / Moist / Just right/ Dry / Very dry

(5-point scale from +2 to -2)

Reason To understand the subjects skin condition

12. Question Overall, what would you say about this place?

Answer Very comfortable / Comfortable / Uncomfortable / Very uncomfortable

(4-point scale: 2 / 1 /- 1 /- 2)

Reason To understand the subjects perception of overall comfort

Part B of the questionnaire contains information obtained by pure observation. It includes

i) time of interview, ii) location of interview, iii) the immediate weather conditions during



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the survey, iv) the subjects clothing and activities during the interview and v) the subjects

demographic background (gender and age composition).

The time of the interview is recorded by the interviewer with his or her watch synchronized

with the Hong Kong Observatorys timing system. The location of the interview is

marked on the map provided in the questionnaire. The exact location of the survey is

shown in Appendix 5. The immediate weather conditions are observed by the interviewer

during the survey.

The clothing of the subjects is recorded by the interviewer using the garment checklist

provided in the questionnaire. The checklist was extracted from ASHRAE Standard

55-2004 and ISO Standard 7730 (ASHRAE, 2004, ISO, 1994). Figure 3 shows the

garment checklist included in the questionnaire and the clothing insulation value of each

item. Clothing insulation is defined as the resistance to sensible heat transfer provided by

a clothing ensemble; it is expressed in unit clo. The ensemble clothing insulation value is

the sum of individual garment clothing value. Underwear is assumed to be standard values

and different for males (0.03 clo) and females (0.04 clo); it will be added to the total

clothing value. The total clothing value of each subject will be coded into an excel

spreadsheet after the survey.

Figure 3: Garment checklist

The activity of the subject is recorded by the interviewer using an activity checklist

provided in the questionnaire. Activity level is expressed in unit met. 1 met equals to the

energy generated inside the body due to metabolic activity of 58.2 W/m2, which is equal to

the energy produced per unit surface area of an average person of surface area 1.8 m2,



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seated at rest. The activity checklist used was extracted from ASHRAE Standard 55-2004

and ISO Standard 7730 (ASHRAE, 2004, ISO, 1994); it contains three options,

i.e. sitting (1 met), standing (1.2 met) and walking (2 met).

The gender of the subject is observed by the interviewer and the age group (i.e. youth/

middle-aged/ elderly) of the subject is estimated by the interviewer. The design of the

questionnaire has been approved by Professor Baruch Givoni, a renowned expert in thermal

comfort issues (Givoni et al., 2004, Givoni et al., 2006, Givoni et al., 2003). The

questionnaire was eventually translated into Cantonese. In the real survey, the

interviewers are asked to read out the questions word by word in accordance with the

questionnaire. This ensures that the questioning technique used by all interviewers could

remain consistent.

3.2.6 Survey Procedure

University students were employed to conduct the survey. These students are mostly

undergraduates taking social science subjects such as Architecture, Anthropology,

Psychology and Sociology. Therefore, most of them already have some basic knowledge

of conducting survey. Before the real survey was conducted, these student interviewers

were briefed on the purpose of the study; they were taught how to handle the mobile

meteorological station and also practical techniques on conducting questionnaire survey.

Total 8 students were needed in each survey session. The students were divided into 4

survey teams and each team was given a designated place for conducting the survey. Each

team was given a mobile meteorological station; the students had to carry out the

micro-meteorological measurement at the same time while they conducted the questionnaire

survey as shown in Figure 4. As the questionnaire is divided into two parts (Part A and

Part B), each team member was responsible for one part of the questionnaire. In other

words, one member of the team would approach the subjects and ask them the subjective

questions in Part A of the questionnaire. The other member of the team would take care of

the meteorological measurement and make the observation in Part B of the questionnaire.

This splitting of tasks allows simultaneous filling of Part A and Part B of the questionnaire

and thus shortens the time of the survey process; the whole survey process would take about

2 minutes to complete.



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Figure 4: Interviewers are conducting the pilot survey on street

In accordance with the procedure described in preceding studies, subjects within 3 metres of

the mobile meteorological station are appropriate for doing the questionnaire survey

(Spagnolo and de Dear, 2003) because the climatic data recorded by the portable equipment

will be consistent with the climatic conditions experienced by the subjects during the survey.

Each interview lasts about 2 minutes. The interviewers were instructed to invite people

who had been staying at the survey area for some time as well as those who were just

passing by to do the interview. This could avoid the bias of excluding those dislike the

microclimatic environment (e.g. sunlight, wind, etc.) of the survey area and just pass by

very quickly.

In order to eliminate any repeated interview, interviewers had to make sure that each

interviewee was interviewed once only. The first question of the questionnaire tackles this

problems it asks the interviewees if they have done the interview before. If the answer is

yes, the survey will be terminated. Then, the interviewers would look for other

interviewees who had not done the interview before.

To account for the daily changing climatic conditions, the survey was conducted in three

different sessions a day. In summer, the first session started in the early morning 7-9am;

the afternoon session 12-2pm and the evening session 5-7pm. Since the winter time is

shorter, the morning session started at 7-9am; afternoon session 11am-1pm and evening

session 3-5pm.

The survey is coordinated by a survey supervisor who is a researcher employed for this

project. The survey supervisor is responsible for the following tasks:

Arranging time for the survey



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Coordinating student interviewers

Arranging equipment

Seeking permission from Government departments and private companies for

conducting survey in their properties

Monitoring the interview process during the survey

Downloading data from the equipment

The survey supervisor worked closely with the project investigators, student interviewers

and the technical support staff to ensure the survey was carried out professionally and the

data collected were of high standard and quality suitable for the use in this study.

3.2.7 Programme of Survey

A pilot survey was carried out from 18th

-30th

August 2006. A total of 8 undergraduate

students from The Chinese University of Hong Kong were employed for the study and a

total of 937 interviews were completed. The survey was conducted in accordance with the

procedures set out in Section 3.2.6. These 8 students were divided into 4 teams carrying

out the survey in different locations ranging from high-density urban areas to rural new

towns (details are shown in Table 1). The purposes of the pilot survey include:

Test and calibrate the measuring equipment in real conditions

Test and calibrate the questionnaire

Familiar the survey supervisor with the actual processes

Train the student interviewers to improve their practical skills on handling the

equipment and conducting the interview

In a single day of the survey, each survey team was able to complete about 40questionnaires. Based on the results, the original questionnaire has been modified to better

suit the local context. The major modifications to the questions were concerning the

immediately past experiences of the subjects. In the revised version, more options for the

answers were provided. For instance, in Question 4, items such as standing, sitting and

shopping were not included in the original questionnaire but were added after the pilot

survey. Although the data collected in this pilot survey were not used in the actual study, an

initial analysis of the pilot data confirmed that the study was on the right track.



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After the pilot survey, the survey continued from November 2006 to August 2007 and had

been completed on 30th

August 2007. In order to ensure a wide range of environmental

conditions to be captured in the study, the user survey was deliberately conducted in

different microclimatic conditions and types of site. Therefore, the data collected would

allow us to understand how different microclimatic parameters and places affect peoples

outdoor thermal sensation. The details of the user survey such as date, time, location, type

of site, number of completed interviews and team number are summarized in Tables1 and 2.

Table 1 shows the locations of the survey. In summary, the number of interviews

completed on streets, in estates and in parks during a year are 1490, 801 and 411

respectively. More interviews were completed on streets and in estates due to the

localized thermal load difference at the pedestrian level. Figures A3.4-A3.6 in Appendix 3

show the relationship between PET and subjects thermal sensation (TS) recorded at

different site types. These figures are for reference only and detailed analysis will not be

covered in this report. Obviously, the mean air temperature measured on streets and in

estates are normally higher than that measured in parks.

In Table 2, excluding the pilot data obtained in summer 2006, the total number of

completed interviews is 2702. The target subjects are Hong Kong residents, i.e. people

who have been staying in Hong Kong for 6 months prior to the survey. As the primary

objective of the study is to address the comfort requirement of Hong Kong people, for thosewho are not defined as Hong Kong residents, their data are excluded in the analysis.

These cases, however, only account for about 3% of the entire sample size. Among the

2702 completed interviews, 1135 interviews, i.e. 42%, were completed in autumn and

winter of 2006. 1567 interviews, i.e. 58%, were completed in spring and summer of 2007.



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* Site type: P=park, PR=private housing estate, PU=public housing estate, S=street

Table 1: Details of the users wind comfort level survey



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Table 2: Summary of the sample size

3.3 Data Analysis

3.3.1 Data Organization

The microclimatic data collected by the mobile meteorological station and the subjective

data obtained from the user survey are input to a single spreadsheet for analysis; the

spreadsheet contains 7 sections which store different data.

Section 1 contains 4 columns i.e. subject number, date of interview, start time of interview

and end time of interview. Subject number is the number given to each questionnaire for

the purpose of identification. The start and end time of the interview are used for

averaging of the climatic data.

Section 2 contains 10 columns correspond to the Part A of the questionnaire which address

the subjects immediately past experience; their sensation towards various environmental

factors and their overall comfort perception.

Section 3 contains 3 columns containing the clothing and activity data. The clothing

values of the items checked in the garment checklists on the questionnaire are added up and

the sums are entered in the clothing column. The types of activities checked in the activity

checklists are entered in the activity column and the last column translates the types of

activity entered to metabolic rates in met.

Section 4 addresses the demographic information i.e. gender and age of the subjects.



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Section 5 contains 6 columns. The first five columns contain the climatic data i.e. air

temperature, relative humidity, wind speed, globe temperature and solar radiation measured

by the meteorological station. The data entered in these columns are the average values

for the duration of the interview; it is calculated according to the start and end time of the

interview. The last column is mean radiant temperature (Tmrt)2.

During the survey, HKO climatic data such as air temperature, relative humidity, solar

radiation, wind speed and wind direction were downloaded from the Hong Kong

Observatory (HKO) website (http://www.weather.gov.hk/contente.htm)3

for cross reference.

Section 6 has 4 columns containing the measured data from the Meteorological Station of

HKO. Quarter-hourly data are obtained from the daily profiles and the average of any two

succeeding values represents the conditions of the quarter time in between. For example,

if the interview was taken place at 8:22 - 8:24 am, the HKO columns will show the average

values of 8:15 am and 8:30 am.

Section 7 contains the value of Physiological Equivalent Temperature (PET).

3.3.2 Methods of Analysis

Since peoples thermal sensation is subjective, it is therefore difficult to make use of

thermal sensation alone to establish an objective wind requirement for Hong Kong people.Due to this reason, only using PET as a medium could establish the objective wind

requirement directly. Typically, according to international practice, e.g. RUROS project,

the survey environmental data are firstly input into a physiologically developed index, i.e.

PET, which has taken into account the human biological characteristics. Once the neutral

PET is calculated, then the various environmental parameters can be computed based on the

PET calculation. The relationship between thermal sensation (TS), PET and wind is

shown as below.

2Tmrt is defined as the uniform temperature of an imaginary black enclosure in which an occupant

would exchange the same amount of radiant heat as in the actual non-uniform enclosure.Theoretically, it can be calculated from the measured surface temperatures and the correspondingangle factors between person and the surfaces. However, since the theoretical calculation is rathercomplicated, practically Tmrt is determined by measurement of air and globe temperature and windspeed.

3HKO data of air temperature and relative humidity are obtained from Hong Kong Observatory

station, wind speed and wind direction data are from Waglan Island station and solar radiation dataare from Kings Park station.



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In recent years, energy balance based thermal indices are being increasingly applied to

assess human thermal comfort. The Predicted Mean Vote (PMV) is the first and still

popular thermal comfort index, defined by Fanger (1972). However, PMV has deficiencies

in assessing the outdoor human thermal comfort and was then replaced by the more

universally applicable model: Physiological Equivalent Temperature (PET) model,

introduced by Hoppe (1993, 1999). The PET is based on the Munich Energy Balance

Model for Individual (MEMI) and has taken into account of both the environmental

climatic parameters (including air temperature, wind speed, relative humidity etc) and the

human factors (clothing index, activities etc). Although PET cannot be explicitly presented

as linear summation of the climatic parameters, detailed calculation of PET has been

published by Andreas Matzarakis and Bas Amelung, 2008. (Appendix 11). Standard

programme codes in many popular programming languages are also available. The PET

programme coded by the PET original author, Prof. H. Hoppe, is attached at Appendix 12.

All in all, the reasons for using PET as the thermal comfort index for this study are:

PET, based on human physiological modeling and heat balance is the most

comprehensive OUTDOOR thermal comfort index until now.

PET has been widely used for outdoor thermal study by researchers around theworld irrespective of climatic conditions i.e. in both temperate and tropical

climates. (E., Johansson, 2006, A., Matzarakis, 1999, J. Bouyer, 2007 and A.

Gulyas, 2006 etc)

PET is the thermal index used officially by the Germany Meteorological Office

and PETs methodology and parameters have been documented in the German

standard VDI 3787 part 2.

Based on PET, it is relatively straight forward to calculate, using the Fortran

programme, the relationship between wind and thermal comfort under

various environmental parameters. The need for wind is the main focus of the

study.

After collecting all data from the survey, the complete set of data is first sorted in

accordance with the microclimatic conditions during the survey. The whole set of data is

divided into two subsets, i.e. winter 2006 and summer 2007. The winter 2006 dataset

include data collected during autumn and winter while summer 2007 dataset includes data



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collected during spring and summer. More interviews were completed in summer 2007

because summer is the most critical season throughout a year. Therefore, summer 2007

dataset is more important in analysis. This dataset is divided into summer 2007 non-A/C

data and summer 2007 A/C data. The former is the main focus in analysis because

acclimatization effect of the subjects has been taken into account. This distinguishes

subjects who have and have not been to (or stayed in) air-conditioned indoor space within

15 minutes prior to the survey. It is assumed that the level of acclimatization would have

significant effects on the human heat-balance model, which is particularly influential on the

calculation of PET. The data in each subset is then broken down into groups according to

subjects TS vote ranging from -3 to 3 and the corresponding PET value. After that, the

mean neutral PET value of the subjects who have TS=0 (neither cool nor warm) is

calculated. Since PET is a function of climatic variables (Hoppe, 1999), the mean neutral

PET value can establish the wind requirement for Hong Kong people. The findings will be

shown in section 4 in detail. Using this data binning and aggregation approach could

reduce the variations due to individual differences.

4 SURVEY FINDINGS

4.1 Results Based on Summer Data, Summer Non-A/C Data, and Winter Data

In Appendix 3, Figures A3.1-A3.3show the relationship between PET and TS in summer

and winter, and different levels of acclimatization effect have been taken into account.

Based on the summer (Apr Aug) 2007 A/C and non-A/C data (see Figure A3.2 in

Appendix 3), the mean and median nPET are 28 and 29 respectively.

Taking into account the acclimatization effect, survey subjects not having been to an A/C

space are separated for further analysis. Based on the summer 2007 non-A/C data (see

Figure A3.1 in Appendix 3), the mean and median nPET are 27 and 29 respectively.

In Figure A3.3, it shows the PET-TS relationship based on the winter (Nov Jan) 2006 AC

and non-A/C data. When TS=0, the mean and median neutral PET value are 19 and 20

respectively.

Difference in the neutral PET value in different seasons exists due to human adaptation of

different climatic conditions. nPET is usually lower in winter.



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4.2 Further Analysis of Typical Summer and Winter Conditions in Hong Kong Based

on HKO Data

The survey data is further analysed based on HKO typical summer (Jun to Aug) weather

conditions.

Based on HKO 1885-2004 mean air temperature (Ta) data, the mean Ta during Hong Kong

summer months, i.e. Jun to Aug, is 27.9. And based on HKO 1971-2000 monthly Ta

data, the mean daily minimum and mean daily maximum Ta during Hong Kong summer

months, i.e. Jun to Aug, are 26.4 and 30.9 respectively (see Table 3 and also Appendix

6). Furthermore, based on the user survey, taking into account thermal adaptation, the

mean neutral PET=1.1639*HKO-Ta - 4.3683 (with R=0.6777) (see Figure 5). Using thisformula, the mean nPET = 28.1.

The nPET range could be decided based on the above findings and the number of subjects

obtaining TS=0. When PET ranging from 27-29, the survey results show that about

50% of subjects express TS=0 (see Appendix 7), 32% express too warm, 13% express

hot, and 4% expressvery hot.

The winter data is further analysed based on HKO winter (Dec to Feb) typical weatherconditions.

Based on HKO 1885-2004 air temperature (Ta) data, the mean Ta during Hong Kong winter

months, i.e. Dec to Feb, is 16.3. And based on HKO 1971-2000 monthly Ta data, the

mean daily minimum and mean daily maximum Ta during Hong Kong winter months, i.e.

Dec to Feb, are 14.7 and 19.2 respectively (see Table 3 and also Appendix 6). Using

the formula of PET=1.1639*HKO-Ta - 4.3683 (with R=0.6777), the winter nPET is 14.6

(see Figure 5).

The neutral PET range could be decided based on the above findings and the number of

subjects obtaining TS=0. When PET ranging from 14-16, about 70% of subjects

express TS=0 (see Appendix 7). At this range, only 21% express too cool and 2%

expresscold. Nobody expressesvery cold.

A TS-PET relationship under typical Hong Kong summer and winter conditions is attached

in Appendix 9. The understanding suggests that given a typical weather conditions, the

survey subjects will report an increasing TS, i.e. from -1 to 3, when PET increases.



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Table 3: HKO 1971-2000 mean daily minimum and mean daily maximum air temperature

Figure 5: The adaptive neutral PET as related to HKO air temperature data

4.3 Establishment of Wind Requirement Using Neutral PET Value for the Summer

The wind requirement could be established using the neutral PET value. Under the

typical summer condition defined based on HKO long-term climatic data, the mean air

temperature is 27.9 and mean neutral PET value is 28.1.

The wind requirement could be established using these data. In Table 4, it is assumed that

the neutral PET is 28.1, air temperature 27.9, Tmrt ranging from 30-344

and relative

humidity 80%, a wind speed of 0.53-1.30m/s would be required.

Calculation of the nPET from the HKO 1971-2000 dataset has also been conducted. From

the HKO technical note No. 83, the mean summer temperature is 28.3. Using the formula,

the mean nPET is 28.5. Under this condition, a wind speed of 0.48-1.29 m/s can be

4In Figure 6, Tmrt 32-34 has high frequencies based on the summer 2007 non-A/C data.



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identified (Appendix 15). Hence there is insignificant difference in the recommended wind

speed for long-term and short-term climatic data set.

Figure 6: Tmrt of HK urban conditions based on summer 2007 non-A/C data

*Ta=air temperature, Tmrt=Mean Radiant Temperature, V=wind velocity

Table 4: Climatic requirements when neutral PET=28.1

4.4 Wind and Thermal Comfort in the Winter Months

The winter months in Hong Kong is mild. Based on Appendix 7, the survey results

indicate that even at PET of 13 or lower, only 42% of the surveyed subjects express

TS=-1 or lower. For Hong Kongs typical mean winter air temperature of 16.3 , assume

Tmrt of 17 (in shade), wind speed needs to exceed 3 m/s to result in PET of 13 or

lower. Hence, it is concluded that except for exposed conditions in very windy days,

thermal discomfort due to wind is unlikely to be an important issue.



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4.5 Various Environmental Conditions for Summer nPET=28.1

Figure 7: Various environmental conditions for summer nPET=28.1 (also see Appendix 10)

Referring to Figure 7, for example, when air temperature is 28, if one were to walk or sit

under shades (hence in condition of no solar radiation and low Tmrt of 30 ), a light breeze

of about 0.5 m/s over the body would likely to allow one to achieve thermal comfort.

Take another example of a cooler summer day of air temperature of 26 . If one were tobe under shades, it is possible to be thermally comfortable without wind.

Take yet another example of a hotter summer day of air temperature of 30. If one were

to be under shade, one needs wind of 2 m/s or more to cool down.

Note that in all the three examples, it is very important that shades are provided. If one

were to be under the direct sun in the summer in Hong Kong, it is unlikely to be thermally

comfortable.

5 CONCLUSION

The summer months are considered to be of concern for urban thermal comfort in Hong

Kong. HKO long-term air temperature data have been used to establish the nPET under

typical HK summer condition. Based on the survey, it is established that the summer

mean nPET is 28.1, and about 50% of the surveyed subjects express nTS when PET is in

the range of 27-29. 32% express thermal sensation of too warm, 13% hot and 4%

very hot. For the summer nPET = 28.1, for example, under a mean HKs summer air



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temperature of 27.9, relative humidity of 80%, and a person standing or walking under

shade on streets or in urban spaces of Tmrt of 30-34, a light breeze of 0.53-1.30m/s

would be thermally neutral.

Due to thermal adaptation, the winter nPET is lower, at 14.6 under HK typical winter

conditions. About 70% of the surveyed subjects would express nTS when PET is in the

range of 14-16 . Even at PET of 13 or lower, only 42% of the surveyed subjects

express TS=-1 or lower. For Hong Kongs typical mean winter air temperature of 16.3,

assume Tmrt of 17 (in shade), wind speed needs to exceed 3 m/s to result in PET of 13

or lower. Hence, it is concluded that save some exposed conditions in very windy days,

thermal discomfort due to wind is unlikely to be an important issue.

Moreover, based on the survey findings, when lower air temperature and higher wind speed

combine together, the chance of obtaining TS=0 would be greater. This is shown in

Appendix 4. In Figure A4.1, it shows that the percentage of the subjects getting TS=0

increases gradually with an increasing wind speed. Figure A4.2 shows that air temperature

decreases gradually with an increasing wind speed. When these findings combine together,

it could be concluded that lower air temperature together with a higher wind speed could

increase the probability of getting TS=0.

Hence, based on the survey findings, two ways are recommended to improve the windenvironment for Hong Kong and enhance peoples thermal comfort level, especially in

summer:

i) To improve Hong Kong wind environment by ensuring a conducive wind

environment with wind speed of0.53-1.30m/s in the city through better planning,

optimal development potentials and building coverage, layout and disposition.

ii) To reduce solar radiation gains on pedestrian on streets or in urban open spaces by

providing shades. Canopies covered building recesses and walkways, colonnades,

and so on are useful. Tmrt under shades is in the order of a few degrees higher

than air temperature. For a summer temperature of 27.9, Tmrt in shades is

about 30-34, whereas if one were under the sun, Tmrt can be as high as

50-60 and it is not realistic to achieve thermal comfort under such a high Tmrt.

In short, providing shading is very important.

iii)To reduce the localized thermal load with greening. Trees and their canopies,

shrubs, flower beds and grass areas are effective. The evapotranspiration of



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plants reduces sensible temperature [ie. Lower the air temperature (Ta)]. For a

small and green urban park of a size of say 100m x 100m, it can have the localized

thermal load of about 2-3 lower than nearby streets. An oasis like this in the

urban area can greatly enhance the probability of pedestrian thermal comfort

environment when traversing the city.

The above suggestions to reduce the air temperature (Ta) and mean radiant temperature

(Tmrt) due to solar radiation could further improve human thermal comfort by lowering the

environmental PET value.

The survey findings suggest a range of wind environment needs for Hong Kong, i.e. a light

breeze of 0.53-1.30m/s. Nonetheless, the process of establishing a standard is inevitably

related to the governments urban planning policy, the social and political environment, and

so on. Therefore, apart from the findings of this study, other social and political factors

should also be taken into account.

6 POSTSCRIPT

Further analysis using statistical simulation was carried out by PlanD statisticians. The

findings are for reference (see Appendices 14 and 15).

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8 APPENDICES

Appendix 1 Details of Measuring Equipment



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Appendix 2 Questionnaire for Users Wind Comfort Level Study



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Appendix 3 Charts Showing Relationships between PET and TS

Figure A3.1 PET vs. TS (Summer 2007 Non-A/C Data)



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Figure A3.2 PET vs. TS (Summer 2007 A/C + Non-A/C Data)



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Figure A3.3 PET vs. TS (Winter 2006 A/C + Non-A/C Data)



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Figure A3.4 PET vs. TS (Summer 2007 Non-A/C Data, Parks)



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Figure A3.5 PET vs. TS (Summer 2007 Non-A/C Data, Estates)



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Figure A3.6 PET vs. TS (Summer 2007 Non-A/C Data, Streets)



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Appendix 4 Frequency Charts Showing Relationships between Air Temp, Wind

Speed and TS

Figure A4.1 Frequency Chart Showing Wind Speed and % of Subjects Obtaining

TS=0 Based on Summer 2007 Non-A/C Data

Season Summer 2007

Adaptation No AC within 15 min prior survey

Place Park + Estate + Street

Percentage of Thermal Sensation = 0

(All Places, Summer 2007, non air conditioned subjects)

0

10

20

30

40

50

60

70

80

WS


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Appendix 5 Maps of Summer User Survey Locations in Chronological Order

Figure A5.1 Survey at Kwun Tong Road, Kwun Tong, at 7-9am on 12 April 2007



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Figure A5.2 Survey at Kwun Tong Road, Kwun Tong, at 11am-1pm on 12 April

2007



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Figure A5.3 Survey at Kwun Tong Road, Kwun Tong, at 3-5pm on 12 April 2007



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Figure A5.4 Survey at Yu Man Fong, Kwun Tong, at 7-9am on 12 April 2007



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Figure A5.5 Survey at Yu Man Fong, Kwun Tong, at 11am-1pm on 12 April 2007



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Figure A5.6 Survey at Yu Man Fong, Kwun Tong, at 3-5pm on 12 April 2007



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Figure A5.7 Survey at Yeung Uk Road, Tsuen Wan, at 7-9am on 12 April 2007



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Figure A5.8 Survey at Yeung Uk Road, Tsuen Wan, at 11am-1pm on 12 April 2007



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Figure A5.9 Survey at Yeung Uk Road, Tsuen Wan, at 3-5pm on 12 April 2007



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Figure A5.10 Survey at City One Shatin, Shatin, at 7-9am on 28 April 2007



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Figure A5.11 Survey at City One Shatin, Shatin, at 11am-1pm on 28 April 2007



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Figure A5.12 Survey at City One Shatin, Shatin, at 3-5pm on 28 April 2007



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Figure A5.13 Survey at Hong Kong Park, Admiralty, at 7-9am on 28 April 2007



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Figure A5.14 Survey at Hong Kong Park, Admiralty, at 11am-1pm on 28 April 2007



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Figure A5.15 Survey at Hong Kong Park, Admiralty, at 3-5pm on 28 April 2007



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Figure A5.16 Survey at Tin Shui Wai, at 7-9am on 28 April 2007



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Figure A5.17 Survey at Tin Shui Wai, at 11am-1pm on 28 April 2007



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Figure A5.18 Survey at Tin Shui Wai, at 3-5pm on 28 April 2007



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Figure A5.19 Survey at Tung Chung, at 7-9am on 28 April 2007



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Figure A5.20 Survey at Tung Chung, at 11am-1pm on 28 April 2007



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Figure A5.21 Survey at Tung Chung, at 3-5pm on 28 April 2007



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Figure A5.22 Survey at Vision City, Tsuen Wan, at 11am-1pm on 9 May 2007



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Figure A5.23 Survey at Vision City, Tsuen Wan, at 3-5pm on 9 May 2007



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Figure A5.24 Survey at Man Wa Lane, Sheung Wan, at 7-9am on 19 July 2007



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Figure A5.25 Survey at Man Wa Lane, Sheung Wan, at 12-2pm on 19 July 2007



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Figure A5.26 Survey at Man Wa Lane, Sheung Wan, at 5-7pm on 19 July 2007



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Figure A5.27 Survey at the Central, Central, at 7-9am on 19 July 2007



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Figure A5.28 Survey at the Central, Central, at 12-2pm on 19 July 2007



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Figure A5.29 Survey at the Central, Central, at 5-7pm on 19 July 2007



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Figure A5.30 Survey at Shun Tak Center, Sheung Wan, at 7-9am on 19 July 2007



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Figure A5.31 Survey at Shun Tak Centre, Sheung Wan, at 12-2pm on 19 July 2007



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Figure A5.32 Survey at Shun Tak Centre, Sheung Wan, at 5-7pm on 19 July 2007



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Figure A5.33 Survey at Gage Street, Sheung Wan, at 7-9am on 19 July 2007



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Figure A5.34 Survey at Gage Street, Sheung Wan, at 12-2pm on 19 July 2007



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Figure A5.35 Survey at Gage Street, Sheung Wan, at 5-7pm on 19 July 2007



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Figure A5.36 Survey at Seafront, Causeway Bay, at 7-9am on 26 July 2007



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Figure A5.37 Survey at Victoria Park (near Children Playground), Causeway Bay, at

12-2pm on 26 July 2007



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5-7pm on 26 July 2007



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7-9am on 26 July 2007



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Planning Department: Urban Climatic Map and Standards for Wind Environment Feasib

Date post:	05-Apr-2018
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Comfort Level Survey

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