BUILDING SCIENCE BLD60803 | CASE STUDY: ANALYSING PASSIVE DESIGN STRATEGIES | TUTOR: DR. SUJATAVANI GUNASAGARAN AZEERAH ALI 0328906 | CHONG XIAN JUN 0332605 | LOI CHI WUN 0328652 | HAFIZ MASRI 0334944 | NG JING YUAN 0331472 | NG ZIEN LOON 0328565 | NICHOLAS WONG 0328559 | ONG HUEY CHYI 0326649 | RAEMI SAFRI 0328385 | YEW JEY YEE 0327708
Suasana PjH, Putrajaya Suasana Putrajaya is a 14-storey mixed-commercial development in the city of Putrajaya. Comprising of two tower blocks with two basement levels, with a gross floor area of 77,837 square metres. In reflectance of the city and its Malay cultural identity, the building has two skins; external glass facade (Malay ‘Songket’ pattern fritted to provide necessary shading and cut out direct solar penetration into the internal spaces through windows), and internal building envelope (low-e glass with flux sensor).
SUN PATH CHART
The double-skin facade has vegetative balconies that enhances sun shading through the use of hanging plants. However, the office spaces in Suasana PjH are not naturally ventilated, hence this study aims to focus on the facade and effectiveness of its sun shading device. The building also does not use a typical shading device, thus we conducted an experiment to test the effectiveness of the sun shading device on North-East and North-West facade at Block A, through temperature recordings and interior sun shading simulations.
SOLAR EXPOSURE LEVEL
PASSIVE DESIGN: SUN SHADING DEVICE Based on the sun path chart and solar exposure level diagram, all facades of the building are exposed to the sun at different time.
CLIMBERS
North-East South-East
North-West facade and South-East facade receive direct sunlight from West and East respectively. Facade as the sun shading device can filter direct sunlight to the interior space North-West
However, sun shading facades at North-East and South-West are tilted to block the direct sunlight perpendicularly. Source: andrewmarsh.com
Green Balcony
Section of Green Balcony
South-West GLASS SUN SHADING FACADE TILTED GLASS SUN SHADING FACADE CLIMBERS
Source: SketchUp SunHours
“Green balconies” with hanging plants at the planter box act as sun-shading device. Climbers draping over to the levels below provide partial shading for the interior space, thus reducing solar radiant heat gain.
SUN SHADOW PATTERN GLASS SUN SHADING FACADE 9AM
12PM
3PM
21 MAR
The outer sun shading glass is made of glazed heat strengthened glass that has high resistance to thermal load. Glazing gives additional strength to wind load and thermal stress.
22 JUNE
Section of Double Facade
Double Facade Gap
The double facade prevents solar radiation from directly entering the interior office spaces by using air between the 2 facades acts as an insulator. The cavity between the external and internal glass facades is naturally ventilated and acts to cut down direct solar heat transfer.
22 DEC ‘Songket’
The eastern sun shines on the South-East and North-East facade. The adjacent building does not shade the building as it is situated further. North-East glass facade is tilted to avoid direct eastern sunlight to penetrate the interior.
The sun is situated right above the building, does not get much of daylight from the sides. The skylight in the middle of each blocks of building allows daylight to penetrate the interior.
South-West glass facade are tilted towards the western sun which reflect the sunlight. North-West of the building receives direct western sun. The facade at South-East and North-East help reduced the heat gain and glare.
Fritted Ceramic Glass
Exterior glass facade fritted with the ceramic Malay ‘Songket’ pattern provides the necessary shading to the building. The fritting takes 50% of the surface area, cutting out 50% of solar penetration into the internal spaces through window. The tilted facade is used to block the sun from East and West.
The space between the the sun-shading fritted glass and the internal building envelope is open to the sky, creating a chimney stack ventilation effect that will naturally evacuate hot air away from the lower level. The air between double wall gets heated by solar radiation and rises up through the gap between the floors, constantly moving, reducing the heat movement to the interior spaces, dropping air pressure. Low air pressure draws cooler air into space though gap on facade.