Wind and Water Cafe

1. Asian Architecture
[ARC60403/ARC2234]
PROJECT 1: CASE STUDY
Name: Koh Kar Yi
Student ID: 0320567
Lecturer: Ms. Nurul Alia Ahamad
Submission Date: 28 Jun 2016
The passive cooling design strategies used in the Wind and Water Café
in South Vietnam to create a ‘natural air conditioned environment’

2. CONTENTS
Abstract
1. Introduction
2. Building Overview
3. Passive Cooling Design in Tropical Climate
3.1 Solar Control
3.1.1 Spatial Arrangement
3.1.2 Shading Systems
3.1.3 Limitation (Roof Design)
3.2 Evaporative Cooling
3.2.1 Artificial Lake (Evaporation)
3.2.2 Bamboo Forest (Evapotranspiration)
3.2.3 Limitation (humidity)
3.3 Air Ventilation
3.3.1 Computational Fluid Dynamic (CFD) analysis
3.3.2 Building By Block
4. Conclusion
5. References and Bibliography

3. Abstract
The research study involves the analysis of passive cooling design strategies used in
the Wind and Water Café in South Vietnam to create a ‘natural air conditioned environment,’
the term is used by the architect, Vo Trong Nghia to describe a comfortable environment
created by the use of various natural systems. The paper will first discuss about the two main
challenges of the application of passive cooling design in tropical climate which are high
humidity and excessive heat load, followed by the design strategies used by the architect in
Wind and Water Café. The building has adopted both traditional Vietnamese architectural
features and contemporary building technologies to improve users’ thermal comfort and
increase energy efficiency. For example, the artificial lake surrounding the café helps to cool
the wind by evaporative cooling; the use of landscape for sun shading; space distribution to
reduce heat gain; as well as the building form and orientation generated and determined by
Computational Fluid Dynamic (CFD) analysis. A series of literature review will be conducted
to evaluate the effectiveness of passive cooling design used in the building. Besides, relevant
suggestions of possible improvements will be discussed.
Keywords: passive cooling, tropical climate, solar control, air ventilation, evaporative cooling.
1. INTRODUCTION
Similar to many other countries in the world, traditional architecture in Vietnam has lost its
identity and is replaced by globalized homogenous housing language to accommodate the
needs of the modern society for growing population. Limited land left after housing the people
has retrained the use of open spaces for greenery and public areas, threatening human well-
being especially in physical, cultural and social aspects.

4. The term ‘natural air conditioned’ is used by the architect, Vo Trong Nghia, one of pioneers
of green architectural design in Vietnam, to describe a comfortable environment created by the
use of various natural systems such as tree shading, the play with sunlight and air ventilation
in order to replace mechanical air conditioning. According to the architect, the area of greenery
per person in Vietnam is relatively low which is only 0.7m2 per person comparing to an average
of 66.2m2 per person in East Asia. (in:situ 2015 - Vo Trong Nghia, 2015) Therefore, in response
to rapid industrialization that causes frequent power shortages, increasing temperatures, high
levels of pollution and reduced green spaces, the architect has employed a number of passive
design strategies in order to provide thermal comfort to the users and to simultaneously address
the demand of local society for low cost housing.
This paper will investigate on the workability of design strategies used in Wind and Water
Café in response to the tropical climate of South Vietnam to create a ‘natural air conditioned
environment’ by responding to the following question:
1. What are the challenges of the application of passive cooling design in tropical climate?
2. How does the spatial distribution respond to its context in order to reduce solar heat gain?
3. Is the application of evaporative cooling effective in hot and humid climate and why?
4. Is the consideration of building feature sufficient for effective cooling and why?
5. How does the building form respond to the context in order to improve air ventilation?
2. BUILDING OVERVIEW
Located in an industrial area of Binh Duong, next to Ho Chi Minh City, the green-oriented
café was built in the year of 2006 by a local architect, Vo Trong Nghia. The café consists of
one-floor semi-open spaces with an intention to promote ventilation. It is surrounded by an
artificial lake and bamboo forest, utilized by the architect as a means for evaporative cooling

5. and natural sun shading. One of the most distinctive features of this building is the expression
of locally available bamboo. This traditional building material of Vietnam is an excellent
carbon dioxide absorbent and has very high growth rate in comparison with other natural
building materials such as timber.
3. PASSIVE COOLING DESIGN IN TROPICAL CLIMATE
In a year-round warm and moist climate, cooling becomes one of the major concerns
in tropical houses. To apply passive cooling system in such climate, there are two main
issues to be revolved, namely high humidity and excessive heat load. In Wind and Water
Café, the architect has used several strategies to achieve cooling effect, including solar
control, evaporative cooling and air ventilation.
3.1 Solar Control
3.1.1 Spatial Arrangement
In Vietnam, sun is in the South.(Lyl, Birkelandl, & Demirbilekl, 2010) Proper
arrangement of spaces can prevent overheating to the building. Spaces where heat is useful
are normally allocated at the South such as laundry space. In Wind and Water Café, spaces
are categorized into served and servant spaces where served spaces are dominant spaces
Figure 1: Photograph showing exterior of Wind and Water
Cafe, surrounded by bamboo forest. (Source: Vo Trong
Nghia Architect Vtn, n.d.)
Figure 2: Photograph showing artificial lake, viewed
from the interior. (Source: Vo Trong Nghia Architect
Vtn, n.d.)

6. such as the bar, stage and VIP room while servant spaces are those that connect and enable
the served spaces to perform its programmatic functions like the kitchen, cashier and toilet.
Served spaces are mostly allocated at the north which remains shady all year round. Served
and service servant space are strategically placed to create self-shading effect for important
served spaces such as the dining area.
Figure 1: Floor Plan showing distribution of spaces in Wind and Water Cafe.
3.1.2 Shading Systems
Shading overhang is a typical Vietnamese vernacular architectural feature. In Wind and
Water Café, both natural means and building design are used as shading techniques. The main
spaces are made fully open with intention to maximize air ventilation. Therefore, large roof
overhangs are designed as a counterbalance to limitation in the use of vertical shading device.
10M
TOILET
KITCHEN
CASHIER
VIP ROOM
BAR
STAGE

7. Being one of the design approaches by the architect, which is to promote integration of
nature with building, greeneries are used not only for the connection with nature but is also
intelligently used by the architect to serve as natural shading systems.
3.1.3 Limitation (Roof Design)
Considering the fact that heat gain of the roof contributes to 70% of the total heat gain of a
building (M. Al-Obaidi, Ismail, & Abdul Rahman, 2014), features of the roof need to be
thoroughly looked into in order to effectively reduce solar heat gain. The roof of Wind and
Water Café is made by a combination of bamboo and steel tensile members to provide
voluminous space with no special consideration to attend to this issue. The contextual and
sustainable aspects of the roof design seem to be overlooked by the architect.
The roof of a building, is fundamentally considered to be the most crucial component in
helping the structure to maintain its cool environment, especially in tropical nations such as
Vietnam. There are a few aspects of the roof which can greatly affect its capability in reducing
Figure 2: Photographs showing roof overhangs of Wind and Water Cafe. (Source: Vo Trong
Nghia Architect Vtn, n.d.)

8. solar gain. As examples, the application of materials with low thermal capacity; roof pitch
value which has an impact on the air flow and heating load; roof orientation and configuration.
Figure 3: Photograph showing roof of Wind and Water Cafe. (Source: Vo Trong Nghia Architect Vtn, n.d.)
3.2 Evaporative Cooling
3.1.1 Artificial Lake (Evaporation)
The café is surrounded by a large body of water. Evaporation of the lake water results
in a reduction in temperature, removing latent heat from the surface from which evaporation
occurs. This in return makes the wind cooler before entering the spaces.
3.1.2 Bamboo forest (Evapotranspiration)
Transpiration is the process of water loss from plants through stomata. Stomata are little
openings found on the underside of leaves that are associated with vascular plant tissues. It is
a passive process greatly affected by the humidity of environment and the moisture of soil.
During the process of water loss (evaporation), latent heat can be removed, achieving similar
effect as evaporative cooling taking place on water surface. This is process is also called
evapotranspiration.

9. Figure 4: Photograph showing surrounding bamboo forest viewed from theexterior of Wind and
Water Cafe. (Source: Vo Trong Nghia Architect Vtn, n.d.)
3.1.3 Limitation (Humidity)
In hot and humid climates, cooling becomes a problem especially in Wind and Water
Café where mechanical cooling system is not used. When humidity increases, the rate of
evaporation becomes lower. In Binh Duong where Wind and Water Café is located, the
humidity level is between 76% and 80% (Binh Duong Province, n.d.) which is so high that
evaporative cooling becomes infeasible. Not only unable to achieve its original intention to
improve thermal comfort, the application of evaporative cooling will increase the humidity
which can in turn cause discomfort to the users. According to Malaysian Standard 1525: 2007,
the relative humidity for comfort cooling is between 55 % and 70 % indicating the exceeded
humidity of the natural atmosphere of Bin Duong. Instead of introducing water body to the
building, building should be designed in order to dehumidify the air to further improve the
environment.

10. Desiccant cooling is effective in hot and humid climates as it helps to reduce the
humidity of air. In high humidity environment, sweating if human body does not occur hence
making the tolerance to high temperature becomes reduced, calling for the need to dehumidify
the air. In the desiccant cooling method, desiccant salts such as silica gel, alumina gel and
activated alumina are used to reduce humidity in the atmosphere. The outside air enters
desiccants cooling system and is dried and then, entering the living spaces. Sometimes,
desiccant cooling is employed in conjunction with evaporative cooling, which the temperature
of air can be adjusted to desired comfort level. (Arif Kamal, 2012)
3.3 Air Ventilation
3.3.1 Computational Fluid Dynamic (CFD) analysis
The V-shape of the roof was generated according to CFD analysis that uses numerical
analysis to analyze problems that involve fluid flows, in this case, wind flow. This aims at
maximizing the wind flowing under the roof of the semi-open building.
3.3.2 Building by Block
As one of the vernacular architectural design in Vietnam, houses are divided into a few
parts and oriented according to its function. In Wind and Water Café, spaces are also divided
into parts. This creates more open spaces and enhances air ventilation between and in each
building block, releases the heat trapped in dining spaces.

11. 4. CONCLUSION
Below shows the effectiveness of passive cooling design strategies used in Wind and
Water Café in hot and humid climate of South Vietnam:
DesignStrategy Effectiveness
Evaporative cooling (water and plants) Less effective
Solar control (Shading and Spatial planning) Moderately effective
Air ventilation (building form and orientation) Effective
Evaporative cooling is not practical in the context of South Vietnam. Instead, it
should be paired with other design to manage the humidity level for more effective cooling.
Although the roof design is not sufficiently contextual-responsive, it has demonstrated some
excellent considerations in reducing solar heat gain in many other aspects such as the space
distribution and orientation. Lastly, the building has shown clear understanding of the
architect in improving air ventilation, making it a counterbalance to other design deficiency.
In comparison with an air-conditioned café, the Wind and Water Café has saved 90%
of the electricity (Vo Trong Nghia Architect Vtn, n.d.) becoming a successful demonstration
of a sustainable architectural design in relation to its context. Wind and Water Café is a
thoughtful incorporation of both traditional architectural features and contemporary building
technologies which successfully enabled it to be a functional building without the equipment
of air conditioner.

12. 5. REFERENCE AND BIBLIOGRAPHY
1. Arif Kamal, M. (2012). An Overview of Passive Cooling Techniques in Buildings:
Design Concepts and Architectural Interventions (1st ed.). Aligarh: Department of
Architecture, Aligarh Muslim University. Retrieved from
http://constructii.utcluj.ro/ActaCivilEng/download/atn/ATN2012(1)_8.pdf
2. Binh Duong Province,. Natural Conditions. Binh Duong: Binh Duong E-
Government Information Center.
3. in:situ 2015 - Vo Trong Nghia. (2015). The 2015 New Zealand Institute of
Architects Conference.
4. Lyl, P., Birkelandl, J., & Demirbilekl, N. (2010). Applying Environmentally
Responsive Characteristics of Vernacular Architecture to Sustainable Housing in
Vietnam (1st ed., p. 9). Brisbane: Queensland University ofTechnology. Retrieved
from https://www.irbnet.de/daten/iconda/CIB_DC22717.pdf
5. M. Al-Obaidi, K., Ismail, M., & Abdul Rahman, A. (2014). Passive cooling
techniques through reflective and radiative roofs in tropical houses in Southeast
Asia: A literature review (1st ed.). Penang. Retrieved from
http://www.sciencedirect.com/science/article/pii/S2095263514000399
6. Vo Trong Nghia Architects Vtn,. Wind and Water Café. Retrieved from
http://votrongnghia.com/projects/wnw-cafe/