Not to be confused with smaller attic fans, these large fans are mounted in the ceiling of the uppermost floor of your home. They work by drawing air from open windows in the house into the attic, where it is released through enlarged vents to the exterior. The air flow in the house can be controlled by the number and location of open windows, as well as the speed of the fan, which usually has several settings. Also, by using a time switch, you can set the fan to run for an hour or so while you're falling asleep, then automatically switches off at night, the fan then automatically switches off and won't run all night when the temperature drops. Well insulated homes should have a minimum of 8 inches of ceiling insulation.
Insulation is easy to install with just a few precautions.
Make sure to cover exposed skin, especially when using fiberglass. Also, be sure to wear a dust mask to prevent breathing in fiberglass particles and wear safety glasses to protect your eyes. If doing the job in the summer, start early in the morning and quit well before the sun heats the attic to uncomfortable temperatures. Attic Fans Attic fans, mounted on the roof, keep the home cooler by reducing the temperature of trapped warm air in the attic. If the attic is cooler, the house temperature will be lower and air conditioners will not have to work nearly as hard to keep the home at a comfortable temperature.