During the summer, your house is too hot. What’s the solution?
The simplest thing to do, of course, is to get a bigger air conditioner. That crude solution certainly works: if you blast enough cold air into a building — even a leaky, poorly insulated building — you can lower the indoor air temperature. (Of course, adopting this approach is no guarantee of success, since central air conditioning systems are often poorly designed and haphazardly installed.)
If you care about efficiency (or your pocketbook), and your house is too hot, you’ll probably prefer a more intelligent and nuanced approach than “I need a bigger air conditioner.”
How do homes get hot?
So before you install a powerful new air conditioner, you should first investigate whether you can address the factors that are making your house hot in the first place.
There are five basic ways that homes get hot:
Deciding which mechanism is responsible for your hot-house problem takes judgment. In most hot homes, the three biggest factors are solar heat gain through windows, thin ceiling insulation, and ducts located in an unconditioned attic.
Solar heat gain through windows
In general, the first line of attack should probably be to address any unshaded windows — especially east-facing windows and west-facing windows. Solutions include:
What about interior shades or blinds? They can help a little bit — but nowhere near as much as exterior shades or blinds. Interior blinds don’t stop solar heat from entering your house. The radiating heat enters through the glass and hits the blinds. The blinds heat up, and then the blinds radiate that heat into the room. So the heat ends up indoors.
For more information on solar-control measures for windows, see these three articles:
Thin ceiling insulation