Asian Architecture| ARC 60403 / ARC 2234 0321577 Foo Wei Min Tutor: Ms. Alia

The Implementation of sun shading strategies

to achieve thermal comfort in 8D House, Bukit Damansara.

Asian Architecture| ARC 60403 / ARC 2234

Research Question

• How does the idea of sun shading from vernacular architecture innovatively adopted in 8D house?

• How does each sun shading strategies act as solution to address heat gain issue in 8D house?

• How does the material of sun shading devices contribute in achieving thermal comfort?

• How does the critical external factors influence the effectiveness of method employed?

• Does the strategies employed help to achieve thermal comfort and what are the impact on living condition?

Introduction

Thermal Comfort

Thermal comfort is the condition of mind that expresses satisfaction with the thermal environment and isassessed by subjective evaluation (ANSI/ASHRAE Standard 55). Satisfaction with the thermal environmentis important because it influences productivity and health.

Passive Design

Sun Shading strategies to resist heat gain in a building.

Ventilation to promote heat loss

*Shading and ventilation work collectively to improve efficiency.*

Shading Devices

Watson and Labs (1983) categorized shading devices into three categories namely solar transmittance of glazing materials, interiorshading and exterior window shades. Solar transmittance is defined as the heat admitting or rejecting characteristic of the glazingmaterials. (As cited in Thamina. A., 2009)

Shading Device

Interior Shading

Solar Transmittance of Glazing material

Exterior Shading

Measures to resist heat gain in tropical climate

• Minimise exposed surface area

• Maximise shading

• Use material with good insulation or heat reflective

• Use material with low U value (thermal transmittance)

• Provide buffer space between exterior and interior

Climate in Bukit Damansara, Malaysia

• Average temperature during hot day: -

min: 31.5 degree Celsius

max: 33.0 degree Celsius

• High relative humidity • High amount of precipitation (rain fall)

Idea From Vernacular Architecture

• Eaves • Envelope • Shading Device

Deep eaves for shading

Allow cooler air for ventilation

Highly insulated and reflective roof to

minimize heat transferred into building

Windows to allow ventilation and to block solar radiation

Innovative Idea

• Deep eaves/overhangs forsufficient shelter

• Reflective and highly insulatedmetal roofing

• Vertical sun screen asshading devices

• Eaves • Envelope • Shading Device

Contextual Respond in shading

• Orientation to minimise heatgain

• Vegetation provide shading

• Gymnasium at lower ground wellshaded from evening sun

• Massing and structure itself asshading device

Solution to Address Heat Gain in 8D House

1) Canopy Roof

Eaves

The large insulated overhanging canopy roof covers the entire building providing shelter and shade.

Material

constructed of lightweight metal deck in a light grey

0.52mm Total coated thickness (TCT)

reflect solar radiation and minimize heat absorption.

Full sunPartial Sun

No sun infiltration

Solar radiation reflected away

Diagram explains relationship between overhang and sun infiltration

2m

7.5m

Section drawing

North-east elevation

External

External

Metal deck 0.52mm TCT

200mm rock wool of 50kg/m3

Parsec reflective foil

Steel Rafter

Air gap 300mmfurther improves heat insulation

Solution to Address Heat Gain in 8D House

Insulationacts as a barrier to heat flow, resist heat gain

Solution to Address Heat Gain in 8D House

2) Sun screen

offset heat radiation, aesthetically pleasure.

2inch by 4 inch vertical metal louvres

Solution to Address Heat Gain in 8D House

3) Surrounding vegetation

Solar radiationCooler air for ventilation

Vegetation shades North-west facadeUse of plantings instead of paving to reduce groundtemperature and the amount of reflected heat.

Solution to Address Heat Gain in 8D House

4) Orientation and Built Form

Properly oriented buildings take advantage of solar radiation and prevailing wind

Lower ground floor and ground floor shaded by the land reclaimed for long stretch of verandah

Evening sun

Shadow casted,Lower Ground Floor Well Shaded

Morning sun

Longer Stretch along North South to reduce heat gain.

noon afternoon evening

Solution to Address Heat Gain in 8D House

5) Internal shading device

Curtain used for interior shading.

Reduce solar radiation from south-east fenestration that serve to catch prevailing wind

To compensate the open plan design for better ventilation

Lam et al (2005) conducted a study to estimate cooling loads and energy use for conditioning due to the heat gain through building envelopes. They investigate the impact of internal shading devices such as venetian blinds on cooling loads and electrical use. Their study shows that use of venetian blinds can bring about an energy reduction of 14%. (As cited in Thamina. A., 2009)

External factors

Factors that influence effectiveness of shading method employed:

• South East fenestration for prevailing wind account high amounts of heat entering the building

(Deep verandah as a solution to this: provide shade and catch cooler air)

• Views: Overlooking KLCC Twin Towers

• Aesthetic Value: Painted black to make the vertical louvres look more prominent.

OverlookingKLCC Twin Tower

Sheltered thus air is relatively cooler

Q5: How does the critical external factors influence the effectiveness of method employed?

Improvements• Longer sun screen to provide sufficient shade

• Avoid façade in dark colour

• trees can act complementary to window overhangs, as they are better for blocking low morning and afternoon sun

proposed for future designs

References

• Chris. R., Paul.D., 2013. Your Home: Design For Climate. Retrieved from http://www.yourhome.gov.au/passive-design/design-climate

• Caitlin. M., 2013. Your Home: Shading. Retrieved from http://www.yourhome.gov.au/passive-design/shading

• Housing for health, 2013. Passive design in tropical zone. Retrieved from http://www.housingforhealth.com/housing-guide/passive-design-in-tropical-zones/

• JTC, 2013. Roofing Contractors: The benefit of zinc roofing. Retrieved from http://www.jtcroofing.co.uk/news/benefits-zinc-roofing/

• Don. P., Donald, P., 2014. Whole Building Design Guide: Sun Control and Shading Device https://www.wbdg.org/resources/suncontrol.php

• Ho, 2015. 8D House.