In hot climates like Cambodia, roofs absorb a large amount of solar heat, which makes buildings warmer and forces air conditioners to work harder. Studies show that roofs with high reflectivity—meaning they stay cleaner and reflect more sunlight—can reduce cooling energy use by up to about 12–15 % in warm regions compared with darker, heat-absorbing roofs. (ScienceDirect)
When a roof is dirty with moss, dust, and organic buildup, its ability to reflect sunlight drops and more heat enters the building. Keeping the roof clean helps maintain its natural reflectivity, meaning less heat gets transferred inside. This can lower the demand on air conditioners and reduce energy costs—potentially saving homeowners and businesses a noticeable percentage on cooling bills, while improving comfort during hot days. (energy.sustainability-directory.com)
