For low-rise residential buildings, the roof is more than half the solution.

The sun heats up the roof structure through radiation, most of which penetrates the roof space due to high emissivity. This affects attic temperature which affects ceiling temperature, which in turn directly increases cooling load. This is called heat gain.

In tropical countries like Malaysia, up to 75% of heat gain is through the roof - and as much as 93% of the heat transmission is through radiation.

An energy efficient 'Green" roof is therefore critical to the overall green effort.

Roof design and ventilation as well as choice of material and insulation determine the overall energy efficiency of the roof.


Radiation: The flow of heat energy between two surfaces with no physical contact (IR Radiation). Resistance to radiation is measured by Emissivity (E).
Conduction: The direct flow of heat through a material, resulting from direct physical contact. Heat transferred through conduction is measured by Conductivity (K).
Convection: Heat transfer by movement of air where cool air is forced down and warmed by the heat source in a continuous cycle.
Reduce heat gain and half the battle is won. You can click on illustrations below to get a detailed explanation on heat transfer in tropical climate.

By reducing heat gain, less energy will be required to make room temperatures cool and comfortable.

During the day, it is heat from radiation which has to be reduced to ensure cooler temperatures and greater comfort.

CoolMax™ products are designed to block 97% of incoming radiation heat.

This should therefore be the first priority for reducing the need for air-conditioning or for making it work more efficiently.

After sunset, radiation ceases to be an issue and convection currents are now needed to more efficiently dissipate heat to the outside.

Mineral rock wool or glass wool store heat and create heatlags.



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