Sustainable Living: 3M FuturewiseTown PlanIntroductionGo BackGo Next: Radiation3M

Front of school building

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3. Roof

Roof insulation Hot air rises so a lot of heat can be lost through the roof of a building. Convection currents are stopped by solid ceilings and draught–proofing as they stop hot air rising and escaping out of rooms.

Heat is also stopped from escaping by using a thick layer of insulation in the roof. The insulation reduces heat loss by conduction because it traps pockets of air and air is a poor conductor of heat. Small convection currents occur in the pockets of air, but if the pockets are small then the heat is trapped.

The thicker the insulation, the more air is trapped and the smaller the amount of heat that is lost. Thick roof insulation reduces conduction and convection but it does not stop heat loss through heat radiation.

Do you want to learn about heat radiation?