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Journal of Middle East Applied Science and Technology (JMEAST)
ISSN (Online): 2305-0225
Issue 12(4) [Part II], August 2014, pp. 643-653

Studying the Effect of Architectural design in
modification of thermal comfort by using ecological
indicators of climate Digital
Field Study of Arab Zadeh's house in Yazd, Iran
First A. Sahar Khodabakhshi, Teacher, Department of Architecture, khomein Branch, Islamic
Azad University, Khomein, Iran. Email:Sahar.Khodabakhshi@hotmail.com
Second B. Amir Samiei, Faculty member, Department of Architecture, khomein Branch,
Islamic Azad University, Khomein, Iran. Email:Samiei@iaukhomein.ac.ir
Abstract—a lot of environmental and allocated factors explain
the thermal comfort and following that the environmental comfort.
Also designers mostly focus on factors which they can control to
improve the quality of comfort in designing process. Temperature,
humidity, solar radiation and wind speed, are environmental factors
that have a direct effect on comfort ranges. Temperature and
humidity don’t have enough impact on the design factors But the
wind and the sun and the ground under the radiant temperature can
The main purpose of this study which is "studying The Effect of
Architectural design in modification of thermal comfort by using
ecological indicators of climate Digital" is to show the impact of
design guidelines in controlling and adjustment of comfort
territories. According to this study, field study and hypothesis
testing is a good way to gather basic data and methodology of this
study is descriptive - analytical. These studies have taken place in
Yazd, A city which is residential only because of intelligent design
and great use of natural resources and modifying and compiling the
difficult weather conditions. Due to the diversity of urban areas in
Yazd we had to limit our studies to traditional places and homes
and we chose Arazb Zadeh'd house which is located in old quarter
of the city. Analyzing the results with simulation and measured
data by valid climatically indicators is Based on the balance of the
human body and the physiological equivalent temperature
predicted in the survey and standard effective temperature.
Comparing these results with data from Yazd synoptic stations
shows that the spatial structure has a great deal of impact on the
micro-climate. the results from this study implies that the designing
process has been very effective on modifying the climate
conditions for people to live in the hottest days of summer and
coolest days of winter.

Keywords— "Climatic Design" ,"TemperaturePhysiology indicator" , "micro-climate", "energy balance
model of the human body", "environmental comfort"
Comfort zones and climatic design have attracted the
attention of urban planners and architects long ago due to
natural forces and their use in improving the living spaces
designed under the headings climate and thermal comfort. In
the field of thermal comfort, environmental variables
combined together as the human physiological environment.
Many studies have been done in the area of thermal comfort
and urban forms which examines how spatial structure has


an impact on the urban aerodynamics and urban areas have
developed a complex structure at a micro scale.
These models include variables such as radiative and
thermal properties of surfaces and the amount of radiation
received by adjacent surfaces and shadows created by
objects [1]. This study expressed and examined the
environmental factors that are affecting thermal comfort
factors and also talks about the factors influenced and
controlled by designing process. The case study reviewing
the structure of the physical design tried to show that
manipulation of the designer in wind control and the amount
of radiation received are two very important variables
specially cause the mitigation of climate which has been
done on the houses in the area of Yazd. Our case study is
Arab Zadeh's house which counts as a historic place and is
located in the old tissue of Fahadan. The data was collected
on the coldest day of year which was 1th of DEY in year
1991 (21th ,December,2012) and at the time period of 9am
to 15pm. These results and the data from Yazd synoptic
Valid indicators of climate analysis is based on the energy
balance of the human body in the form of predicted surveys
(mean vote)1 , physiological equivalent temperature2 and
standard effective temperature3 were adopted. In order to a
fast and accurate simulation and calculation we used the
software Ray Man4, in this research and for final data to be
in clear direction
we used Excel Software.
from a very long ago the studies of thermal comfort were
done in two general ways, which were Laboratory studies
and field studies. The most pioneering research done in this
field was in England in 1833 and was about the Interactions
between climate and architecture [2]. In 1972 Otto
Königsberger and his and colleagues provide a criteria for
designing and construction of housing in a book entitled
"Manual of tropical housing and building". A basic
knowledge of local climate and practices that distinguishes
that from regional climate and human thermal comfort and
designing terms are the topics of this book [3].
Razjooyan analyzed the criteria of comfort, the radiation of
the sun and the wind and its control methods for modulating
the comfort zones in two volumes entitled "Comfort in

Journal of Middle East Applied Science and Technology (JMEAST)
ISSN (Online): 2305-0225
Issue 12(4) [Part II], August 2014, pp. 643-653
harmony with the architecture of the region" [4]. In 1378, in
a book entitled "Climate and Architecture", Kasmaei talked
about climatic factors, climate and structure, climate and
Betli Yen and colleagues offered a new style for the
interaction of city and climate and published it in a book
called " responsive environments" and also emphasized on
Radiation and wind as the most important environmental
factors affecting the operation of urban climates [5].
Modifications and adjustments caused by construction and
changes in the structure of a building in a radiation
condition, Heat, moisture and aerodynamic characteristics of
the surrounding environment were all discussed in a book
named "Microclimatology" [6]. Also various countries have
discussed this issue in different case studies. In a research
entitled "Improving the thermal comfort by environmental
design " , climate factors associated with urban
environments, buildings and human living conditions were
In Bangladesh, a study was done on the impact of climate
Physiologically, the thermal comfort is in a range of
temperature and humidity in which the body's heat
regulating mechanism is at its minimum. [9]. There are
many different interpretations of "thermal comfort".
ASHRAE (American Society of Heating, Refrigerating and
Air Conditioning Engineers) believes that thermal comfort is
a mental condition of an individual when he's satisfied in the
ambient temperature. The "mental condition" implied by
ASHRAE is a mixture of emotional, mental and
physiological conditions known as thermal comfort. There
are many variables in determining the impact of the comfort
zone .Environmental factors, personal factors, including
physical factors (clothes, activity rate, etc.) and
psychological (thermal expectations, length of stay,
experience, etc.) are some limited models for thermal
comfort. Olgiati had a specific definition of comfort zone
which was the lowest energy rate spent to create a favorable
environment. In addition to the definition and principles of
thermal comfort, another field of study has conducted based
on the digital indicators and till this day they have reached to
very important results and factors associated with the
physiology of the human body's energy balance are included
in the results and have very important role in today's
environmental studies. Physiological equivalent temperature
and the average predicted mean vote factors are mainly
known as (PET) and (PMV).[10].One of the most
comprehensive temperature index for a standard effective
temperature is known as SET which ASHRAE was able to
achieve a complete model of it in 1972.

These studies are done based on the relationship between
urban density, ratio of length to width and climatic variables.
The structural model indicates a significant role in the city's
climate situation. [11]. The mere existence of a town
influences climate and when the town changes the climate
changes with it [12]. Urban areas have built a complex
structure in a micro scale. These models include variables
such as radiative and thermal properties of the surface, the
amount of incoming radiation from adjacent surfaces and the
coefficient of sky view and shadows created by objects [1].
Air temperature, wind speed, humidity, radiation are
environmental factors and indicators which define the
comfort limits. Studies have shown that the air temperature
and humidity cannot be considered while designing a plan
but they may be important in some rare cases. But wind and
radiation from the sun and Earth's average temperature could
greatly affect the design process and result. [5].
Intervention of the designer in form, orientation, materials,
coefficient of sky view, and amount of shade can seriously
change wind and exposure indicators. Design solutions to
control humidity and temperature indicators are very limited
and subtle, the connection between climatic and design
factors are shown in figure (1) as two man-made and natural

IV. connection Between Design and Climatically Variables
Numerous studies have been conducted in urban areas,


Journal of Middle East Applied Science and Technology (JMEAST)
ISSN (Online): 2305-0225
Issue 12(4) [Part II], August 2014, pp. 643-653
The method used in this case study is based on observation
and quantitative measurement of environment variables.
This study has taken place in Arab Zadeh's house in Yazd on
the 30th of Azar in 1391(20th December, 2012). The tine
scope of study is 9 am to 15 pm with checking every 10
minutes. This specific time was chosen due to the visible
presence of radiation which is an important factor for
variable weather conditions in this climate. Data was
collected in 2 series, micro-climate data (case study) and the
Urban Climate (which was the data we collected every 10
minutes in the synoptic station on the day of the field study).
Digital environmental indicators were used due to data
comparison and studying the positive or negative effects of
architecture in general. At the end, thermal differences in the
expression of a micro-scale climatic conditions was

explained by the physical properties such as the proportions
Texture and architecture of the City, Yazd is one of the most
striking examples of a hot and dry climates. Location studied
in this research is Arab Zadeh's house and it belongs to a
collection of 13th century buildings that all of them have
special architectural spaces which resembles desert and a
very unique style of architecture. This house is composed of
two parts, an outer and an inner part. Inner part almost fills
most of the house. The courtyard is in the center and upper
parts of the emirate are surrounding the yard each for one
specific season. . The place for collecting data was within
the yard (big yard) at the same distance from each forehead.


Journal of Middle East Applied Science and Technology (JMEAST)
ISSN (Online): 2305-0225
Issue 12(4) [Part II], August 2014, pp. 643-653

In this research, for measuring temperature and humidity the
data logger and for the wind speed the thermal anemometer
was used. All units were installed on the ground and by a
height of 1.1 meters, except for the wind speed receiver
which was installed by the height of 2 meters to avoid the

effects of people and external factors. . Temperature, relative
humidity and wind speed were all recorded in period of each
10 minutes. Vents of thermal anemometer were adjusted to
the wind direction during the work to increase accuracy.
Table 3-3 shows the details of measurement tools used were
used in this st

Parameters of "Physiological Equivalent Temperature",
"Predicted Mean Vote" and the "Standard Effective
Temperature” are calculated through a variety of methods
Due to complexity and extent of relevant equations,
researchers in different areas of expertise, have presented

different models and computer software’s for calculating
mentioned indicators. To analyze the data collected in this
study, Raymn software was used. This model of Raymn was
created by Doctor Andreas Matzarakis to calculate the
radiation flux especially among urban buildings. This model
is one of the best methods for calculating the “Physiological
Equivalent Temperature", "Predicted Mean Vote" and the


Journal of Middle East Applied Science and Technology (JMEAST)
ISSN (Online): 2305-0225
Issue 12(4) [Part II], August 2014, pp. 643-653
"Standard Effective Temperature" [10]. Variables used in
into five
First category is time variables based on year, month, day
and timing based on hour and minute to access comfort
conditions. Second category holds geographical information
such as longitude, latitude and altitude, which provide the
ability to simulate environmental conditions.( but we chose
to relinquish these informations in our study.)
Meteorological variables are used to calculate temperature
indicators such as air temperature, relative humidity, airflow
and the mean radiant temperature. The fourth category
includes personal information that must be modeled as an
effective physiological characteristics such as height,

Fifth category of variables include the type of coverage and
activities. According to the model and the researcher’s
opinion we can recommend a few things to consider as mean
or standard, because physiological data, coverage and type
of activities are very different. For example, we can use the
average conventional for height, weight and age. Moderate
activities, such as driving with 80 W and coverage with 0.9
CLS are considered for both male and female. The
difference between male and female is so insignificant that
After declaring variables and entering data, values for each
of the temperature - physiological parameters are calculated.

"Physiological Equivalent Temperature", "Predicted Mean
Vote" and the "Standard Effective Temperature" and
synoptic station data in the mentioned timeframe for the site
studied and were all calculated by Ray Man software. The
data’s are presented in charts to provide clear and accurate

They used an emotional divide in the definition of this index
which is in the range of -3.5(cold) to +3.5 ( warm). Table 4
indicates the physiological equivalent temperature based on
physiological stress divided by 9 degree for people in
Europe and Southeast Asia. Due to the similarity of the
Asian region in terms of radiation measurement,
measurement is divided in this region.

X. Comparing

Physiological Equivalent Temperature in


Journal of Middle East Applied Science and Technology (JMEAST)
ISSN (Online): 2305-0225
Issue 12(4) [Part II], August 2014, pp. 643-653

As seen in the table above, the East Asian region is in the
same comfort range as a bit hot in Europe. In the present
study, the increased comfort of PET in Europe and
compatibility of people in this region with the extremely hot
weather caused us to use figures of warm areas.
Personal information given is based on a person with age of
35,80 W rate of metabolism and 9% in coefficient
conductivity . Image (3) shows a physiological equivalent
temperature ranged from 9 am to 15 pm in an urban and

micro-climates. As seen in the graph in Figure (3) a huge
difference is between the physiological characteristics of the
micro-climate and urban climate. Micro-climate's graph is
mostly in the time period of comfort zone. (Pale blue)
During the hours of 9 to 11 am it’s mostly in the small and
medium stress range or very much close to it. This weather
conditions continues while the urban climate control charts
often show a very cold climate, except for 12 pm which is


Journal of Middle East Applied Science and Technology (JMEAST)
ISSN (Online): 2305-0225
Issue 12(4) [Part II], August 2014, pp. 643-653

XI. Comparison of Predicted Mean Vote in urban and micro climate
Like other indicators, evaluation of predicted mean vote and appears. As we were told that due to the climate of this
classification of figures were based on physiological stress region and field studies conducted this amount is acceptable
by Matzarakis,in the range of (-3.5) to (+3.5) , which for
includes nine physiological state that is presented in the
table below. If the value of this index is between -0.5 and
Personal information use in the calculation of “Predicted
+0.5 based on defined thresholds, the comfort conditions Mean Vote" are similar to the other indices.


Journal of Middle East Applied Science and Technology (JMEAST)
ISSN (Online): 2305-0225
Issue 12(4) [Part II], August 2014, pp. 643-653
Figure 4 shows the average of predicted mean vote in microclimates (case study) and the urban climate (synoptic
station's data). This figures show a large difference between
two climates. The micro-climate is mostly in comfort zone

or in a low heat stress within hours of a day, unlike the urban
climate graphs which are constantly under cold stress except
hours near the noon which is in the non-stress area.

XII. Comparison of "Standard Effective Temperature" in
Threshold defined in the "Standard Effective Temperature"

Freezing thresholds in average of predicted mean vote are of
less than 14 and very hot with an average of predicted mean
vote of more than 42 a comfort zone between 26 and 30.


Journal of Middle East Applied Science and Technology (JMEAST)
ISSN (Online): 2305-0225
Issue 12(4) [Part II], August 2014, pp. 643-653

Diagram of Standard effective temperature in the locations
Comparing these two charts, just like previous charts shows
that the indicators and data’s in these 2 charts are very
different. As we can see in figure 5, micro-climate is mostly
in the comfort zone during a day. Sometimes between the
hours of 9 to 10 it has a mild cold stress.
Rest of the time chart is in a range of mild heat stress.
XIII. The influence of geometry and design on thermal

climatology studies is based on the connection between
urban densities, ratio of length to width and sky view.
The present study investigated the changing winds and
radiation biology in the form of digital indicators and shows
significant differences in weather conditions in both
That space is designed to weather conditions, to achieve
stress reduction. Arab Zadeh's house is designed based on
spatial proportions, length to width ratio of 1.55, ratios of
2.8 in south view and 3.4 in north view and the ratio of
width to height in the eastern and western fronts is 2.2

Research on urban structure and its impact on urban


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