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Q & A: Insulating Against Convection

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Most recent answer: 10/22/2007
Q:
How can you stop convection from happening? And why is trapped air a good insulator?
- nida khan
Walthamstow School For Girls
A:
Nida -

Convection happens when air moves around, carrying heat from one place to another. So in order to stop convection from happening, you just have to get the air to stay still. Warm air will rise relative to cold air even when nothing else is moving it, so keeping air still is not so easy to do. In double-paned glass windows, for example, air is trapped between two panes of glass. There is nothing in there to make the air move, so very little heat can be lost by convection. If we don't need to see through it, like a wall rather than a window, we can use fiberglass insulation to keep the air from moving.



-Tamara

(published on 10/22/2007)

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