Homeowners and building developers can save on their energy bills by employing passive cooling strategies in their designs. At the same time, they are helping the country become greener.
In warmer climates like Malaysia, air conditioning accounts for an enormous percentage of energy consumption. While energy-saving technologies have helped cut consumption to its minimum, passive cooling solutions can help you live and work comfortably without relying heavily on air conditioning, meaning less money is spent on temperature moderation, and CO2 emissions go down as well.
How passive cooling helps moderate temperature
Active cooling devices include air conditioning systems and other mechanical devices. On the other hand 'passive' cooling devices and strategies work without relying heavily on mechanical assistance.
Architects and engineers who want to employ passive technology in their designs usually look at cooling from three angles - insulation, ventilation and shade. Insulation provides a barrier between outdoor heat and a building's interior. Shade helps prevent transfer of solar heat into an interior or exterior space, and passive ventilation systems draw cool air into a space and expel hot air.
Passive cooling in a warm climate
David Thorpe, Special Consultant of the Sustainable Cities Collective, offers his expertise and extensive strategies on passive cooling techniques that can be used in countries with a warm climate such as Malaysia.
According to Thorpe, buildings must first be well insulated or 'airtight' in order to strategically locate passively cooling ventilation systems. Other recommendations include installing a radiant heat barrier beneath the roof deck, and having highly reflective or green (roof garden) roofs.
Thorpe also suggests taking advantage of prevailing winds by facing the building towards the summer breezes to allow for natural cooling when the outside temperatures rise. To create ventilation, air must also be allowed to exit the building, therefore Thorpe recommends a system that maximises control of air flow - windows in basements can draw cooler air in when needed and adjustable skylights and/or louvres allow occupants to remove or contain rising hot air.
'Shade' is another important aspect of passive cooling. For example, planting a tree outside your window provides shade when the sun is high, and blocks out some heat. Another shading technique includes using greenery to covering rooves and courtyards with deciduous vegetation such as creepers or grapevines. This permits evaporation from the leaf surfaces to further lower the temperature.
Malaysia's lush tropical foliage makes it ideal for taking advantage of natural vegetation to provide passive cooling. A good example of this is Hijauan House in Kuala Lumpur, built by architects at 29 Design whose goal was to "avoid cutting a single tree on site." The house has been carved out all around with courtyards that bring in light, air and green, making for tropical spaces that breathe. At the same time, two fifty-year-old mango trees take centre stage at Hijauan House and provide money-saving passive cooling by directly blocking out the sun on hot days.
By combining natural features (such as trees and other plants) and incorporating passive cooling features directly into the design of a home, homeowners and builders can look forward to saving money and the environment all at once.