Su-Garden

1. Asian Architecture [ARC60403/ARC2234]
PROJECT 1: Case Study Paper
Design features for courtyard as an approach
as passive cooling system In Su- Garden
NAME : YAP WEI TYNG
STUDENT ID : 0314058
LECTURER : MR KOH JING HAO
SUBMISSION DATE : 24th
NOVEMBER 2015

2. CONTENTS
1. Abstract
2. Introduction
2.1. Overview of Su-Garden, Beijing
2.2 Research Questions
3. Passive Cooling System
3.1 What is passive cooling system?
3.2 How courtyard works in a building?
4. Factors of courtyard as passive cooling system For Su-Garden, Beijing
4.1 Su-Garden’s building orientation
4.2 Building structure that was being applied in Su-Garden
4.3 Types of materials in Su-Garden
4.4 Vegetations that was surrounding Su-Garden.
5. Conclusion
6. References

3. Abstract
The purpose of doing the informative study of the use of courtyard as architectural passive
cooling system for a building is to identify whether courtyard acts fully as a passive cooling
system and provide the user of the building a cooling environment. With the courtyard
feature applying in the building, there are many minor details and designs need to be
considerate when applying a courtyard to a building so that it will be fully used as a cooling
system and provide cooling environment in the building. In assisting the validation of
research, literature reviews based on various source regarding courtyards were being applied
to enhance the cooling environment in a building. In order to provide a wider variation of
research, it is important to do some research about existing building that applied courtyard
and fully used as a passive cooling system and that is Su-Garden in Beijing. Su-Garden was a
classical design house that was based on Jiangnan style architecture and adopted the SuZhou
garden as their design concept as in the past until now, Chinese people love to have a
courtyard at their house as it was mainly for poetic purpose design and enjoyable
environment to stay. There are several factors that influence the passive cooling system.
Building structure and the orientation of the building should be considerate so that it is able
response to the climate and sun path. Material and vegetation also important for a courtyard
design as it will influence the heat gain of the building and ventilation of the area. As Su-
Garden also do apply all these factors to fulfil the site context. Hence, it has come to a
conclusion that courtyard is able to provide and act as a good passive cooling system for a
building after fulfils those factors and details that should be considerate when design a
building with courtyard.

4. 2.0 Introduction
2.1 Overview of the Su-Garden Beijing
Su-Garden in Beijing is a magnificent residential bungalow that was designed by applying
the concept of SuZhou Garden and mainly applied the Jiangnan style dwelling. Su-Garden
residential area occupied a total of 810000 square meters and has 54 percent of greening ratio
in the area. For each bungalow size, the building individually has 540 square meters and total
area for each bungalow area owns is 700 square meter. For the spaces in the building, this
building has 3 floors that came with 5 rooms, 2 study room and 4 toilets.
Figure 1. Su-Garden, Beijing. Source from: http://bj.house.sina.com.cn/scan/2010-04-
22/1930342866.html?id=img_s_2#picTop

5. 2.2 Research questions
This case study paper mainly is to research the passive cooling systems, courtyard that was
applied into the building design and how the courtyard works and response to the building.
By responding to the following questions, a thorough analysis has been done throughout the
research and the questions are listed below:
Question 1: What is passive cooling system?
Question 2: How the orientation of Su-Garden acts as a passive cooling system?
Question 3: How the building structure of Su-Garden acts as a passive cooling system?
Question 4: What kind of materials Su-Garden used to build that performs a passive cooling?
Question 5: How does the vegetations of Su-Garden acts as a passive cooling system?

6. 3.0 Passive Cooling System
3.1 What is passive cooling system?
Passive cooling system was a design approach that uses natural elements in concern such as
sunlight, heat, cool or light a building. Through this approach of design, it takes the
advantage of solar energy to either maximise the heating or provide cooling based on a
building design to avoid sun exposure to the interior. By employing this design on a building,
it only required very little maintenance fee which is cheap in terms of fee, it also reduce a
building’s energy consumption by minimizing or taking off the mechanical system that was
used to regulate indoor temperature such as air conditioning system. Besides that, passive
design also more environmental friendly and also provide more green elements into the
building instead of apply mechanical system that only regulate indoor temperature without
considering the health of the environment and will only produce more bad air to the
environment.
There are many kinds of passive design that can be applied to a building such as roof pond
cooling, courtyard or ventilation. Among all these passive cooling system, this study paper
mainly to discuss about courtyard. Courtyard is passive design system that interlocks the
indoor and the outdoor spaces to enhance the building environment and provide cooling
effect to the building. In order to produce the highest level of thermal comfort to the building,
the courtyard geometry and the material used for the courtyard should be considerate during
the design stage. Courtyard can be list to act as a climate responsive design, because it can be
utilized as a suitable place to provide natural and mentally healing environment for the users.
With the courtyard environment, a cooler private area will be provide to the users as it
moderates the climatic extremes, the cool air of the summer night will be kept for a long
period without interruption by the hot and dusty winds. The surrounding building draws out

7. the daylight and cool air from the courtyard. By using running water such as pond during the
dry and dusty climates, it is essential to cool the environment by evaporation.

8. 3.2 How courtyard works in a building?
The courtyard in a building acts as an air shaft, bringing air movement and natural light from
the exterior around the courtyard to the interior spaces. There are three cycles in term of
courtyard’s function.
During the first cycle which is happening in the night time, the cool air from the surrounding
descends into the courtyard and spreads the cool air to the surrounding rooms or buildings.
During the night, most of the building features are cooled such as roof, ceiling, walls, floors,
columns and furniture and preserve the temperature until the late afternoon. The courtyard
releases the interior heat through irradiation to the sky and also may be used during the
summer for sleeping purpose to provide a warm environment to fall asleep.
Figure 3.2.1 First Cycle, source from:
http://www.researchgate.net/publication/258344679_Ecological_Aspects_of_the_Courtyard_House_
As_a_Passive_Cooling_System

9. During around noon time when the sun rise high up to the middle of the sky, second cycle for
the courtyard occurred while the sun rays and radiation directly strikes the courtyard floor.
Cool air that was preserve during the first cycle in the night time started to rise and leaking
from the interior space to the exterior space. Convection currents from the room will be set
up that may afford further comfort. During this hour, courtyard will be as hot as chimney; the
ambient temperature will be very high for the exterior space. However thick walls for the
courtyard will be very useful at this timing as they do not permit the external heat to penetrate
into the building includes the interior spaces. The walls were excellent insulators and time-lag
that caused by the wall of the average thickness may reach as high as 12 hours. Through
these features applied to afford the noon time extreme climate, the house still remains
enclosed during the day and is insulated from heat gain excellently during the day.
Figure 3.2.2 Second Cycle, source from:
http://www.researchgate.net/publication/258344679_Ecological_Aspects_of_the_Courtyard_House_
As_a_Passive_Cooling_System

10. When the time reaches to late afternoon, the third cycle is happening as the courtyard floor
and the interior spaces are getting warmer as further convection currents are being set up
during that time. Cool air that was trapped within the interior spaces will spread out by the
sunset. During that late afternoon period, all the spaces from the exterior until the interior
spaces are protected by shadows in the interior spaces that were enclosed with high walls.
While the sun set, the temperature of the surrounding will then slowly decrease and cooler air
will start to descends to the interior through the courtyard once again. The new cycle for the
courtyard begin.
Figure 3.2.3 Third Cycle, source from:
http://www.researchgate.net/publication/258344679_Ecological_Aspects_of_the_Courtyard_House_
As_a_Passive_Cooling_System

11. 4. Factors ofcourtyard as passive cooling systemfor Su-Garden, Beijing
4.1 Su-Garden’s building orientation
Building orientation in the design stage for the courtyard was very important as it
significantly affects the climate and the comfort of the exterior space and the interior spaces.
By considering the orientation of the courtyard and the building, it can positively influence
the microclimate condition within the courtyard such as sun path, wind direction and shading
performance which are important to provide certain comfort and cooling environment to the
interior spaces through the courtyard. Instead of just affecting the sun strikes through the sun
path to the courtyard, orientation of the building also has a direct effect with the ventilation or
wind speed. For instance, with the suitable orientation of the courtyard can significantly
improve the thermal comfort of the interior space, but in the other hand, without considering
and orientating the building and courtyard in the improper way will cause irrespective of
solar angles and wind direction which would create thermal discomfort.
Figure 4.1.1 Shading area, source from: www.dr.eju.cn
Shadingshows
orientation.

12. Through the figure that was shown above, Su-Garden was well orientated as the shading that
was created by the wall has greatly interrupted the sun ray strikes directly into the courtyard
and provides a cooling environment. With the participants of the thick wall as the insulator,
the environment in the space reaches thermal comfort and cooling environment.

13. 4.2 Building structure that was being applied in Su-Garden
Courtyard are also a good ventilation design when it was designed in a proper way as in the
multi- story building, courtyard acts as a ventilation shaft which is a passageway that serves
as ventilation purpose. With this ventilation shaft, the cross ventilation for the interior spaces
will then activated and provide a cooling environment without mechanical system. However,
dimension of the courtyard must be carefully considerate as it has a strong relationship in
terms of its width and depth to trigger the cross ventilation in the building. If the courtyard is
narrow and deep, courtyard may only be just a shaft that not bringing cool air to the
surrounding rooms which became a useless design and fail to reach the passive cooling
system requirement. Besides that, the loggia that are covered patios should be open to the
courtyard and it usually face north so that it was able to reach the maximum cooling effect.
Figure 4.2.1 Air feature in Su-Garden, source from www.dr.eju.cn
Through the figure above shown that wide courtyard was the basic requirement to reach the
cooling effect as it will trigger the cross ventilation happens in the building and provide a
cooling environment.

14. Figure 4.2.2 Ventilation shaft, source from:
http://www.researchgate.net/publication/258344679_Ecological_Aspects_of_the_Courtyard_House_As_a_Passive_Cooling
_System
The figure above shows how the courtyard activates the cross ventilation of the building
through the ventilation shaft. With the narrow and deep courtyard, the cross ventilation will
not occurred and the building will not have a cooling environment.

15. 4.3 Types of materials in Su-Garden
Using the right material is important for a building’s design for sustainability and fulfils the
passive cooling system. There are two main materials that were being used in the Su-Garden,
Beijing.
First of all is concrete for walls, columns, beams and structures of the building. This building
was mainly built with concrete as concrete has excellent thermal mass. As concrete is a dense
materials, it was able to store huge amount of heat from the exterior before it was transfer
into the interior. By storing the heat, the heat transfer from the exterior will be then slowed
down and maintain the cooling environment for the interior spaces. Therefore, it has been
lower the usage of the air conditioning. Besides that, considering the nature and preserve the
nature environment also a way to ensure the environment clean and less CO2 that increase
heat to the environment. Producing concrete actually required less energy than producing
other building material such as aluminium, stainless steel or glass. According to a study quote
by the NRMCA, they have concluded that 1.4GJ/t of energy required producing a ton of
concrete; however it required 30 GJ/t of energy to produce steel and 90 GJ/t of energy to
produce stainless steel. With less energy required, CO2 emission will be relatively lower and
environmental friendly because it will cause less pollution to the environment.
Next material that was mainly applied to the whole building was timber. Timber is one of the
few natural building materials that were mainly being used as it was environmental friendly
and it was durable. With similar eco-friendly properties with concrete, timber just required
2GJ/t of energy to produce one ton of timber, which is low CO2 emission compared to others
materials. Wood is also a good and natural insulator due to the air pocket within their cellular
structure. It was able to reduce the amount of energy used to heat and operate a building.
Besides that, as an effective insulator, it also can store large amount of heat and ensure the

16. interior space is cooling and always in thermal comfort. Su-Garden applied timber as the
timber flooring to improve the ventilation from the ground to the top of the building. It also
enhance the cross ventilation that occurred in the building to maintain the interior spaces’
cooling environment.
Figure 4.3.1 Interior space, source from: www.dr.eju.cn
Concrete
TimberFlooring

17. 4.4 Vegetations that was surrounding Su-Garden
Courtyard will never exists without natural elements surrounding the building, thus
vegetations planted surrounding the buildings are very important as it also act an important
role in passive cooling system. Trees, shrubs and flower pot plants that was planted in the
courtyard are able to affect the thermal comfort of the surrounding environment significantly
as they provide shaded area as the high wall of the courtyard does. However choosing plants
are important as some of the plants required high maintenance fee or required more time to
take care will be troublesome, choosing plants that are easy to take care and required less
caring with long lifetime and for trees should be moderately tall and able to provide sufficient
shaded area. With certain amounts of green elements, the environment of the building will be
cooling. To enhance the cooling environment, using water body such as pond or water spray
within the courtyard also provide a good thermal performance. With the pond, it will increase
the humidity of the area during sunny and hot day, thus it will be comfortable instead of hot
environment. With some design idea implanted to the courtyard will also enhance the overall
view of the courtyard and provide a mentally healing environment that will also release stress.
Figure 4.4.1 Courtyard in Su-Garden with plantations, source from: www.dr.eju.cn

18. 5.0 Conclusion
After finish my research about courtyard, I have to agree that Su-Garden from Beijing is the
best example to show the quality and the requirements that a courtyard should have in terms
of passive cooling system. Su-Garden in Beijing also fully showed the importance and
benefits of using courtyard as passive cooling system.
By adopting all those important courtyard elements that I had listed through my research
paper, it has achieved the passive cooling system that most of the building lack of and
required in the future. By some adjustment of the building orientation creates a big different
of environment for a building experiences and reaches the thermal comfort which is a
brilliant idea as it was using same materials and locations to build but provide a totally
different experience from the exterior to the interior of the building. As passive cooling
system not only save energy to provide a cool and wonderful environment, it also provides
more nature elements to the environment which this planet was currently suddenly lack of.
Furthermore, the energy and operational cost has significantly lowered by selecting material
wisely for the building. With more plantation of nature elements in the courtyard will
somehow emerge the building with the nature and restore the nature of the planet from what
it used to be.
Through this research paper, I have realized that to own a cooling environment, not just
installing a mechanical system to provide the interior cooling but worsen the exterior of the
environment but can be achieve while compromising with the nature. With wise planning and
clever decision in selecting materials that responds to the surrounding, we are able to have a
better and more sustainable design for the sake of the human races’ health and the benefits of
the nature.

19. 6.0 References
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