Sustainable Living: 3M FuturewiseTown PlanIntroductionGo BackGo Next3M

Secondary glazing

Back to front of school building

Big windows can let a lot of heat energy out of a room on a cold day. Less heat is lost if a second pane of glass is added behind the first pane. This is called secondary glazing. It works because it traps a layer of air between the glass layers.

Air is a very poor transmitter of heat because the particles in air are very far apart.

This makes air a good insulator of heat
and a bad conductor.