roof-fan

The attic is a great place for unwanted heat in the summertime. A poorly ventilated attic can
reach temperatures of up to 170 degrees causing your air conditioning system to work
overtime on order to cool your home! As the attic air heats up, it expands so rapidly that the
hot air cannot escape quickly enough through the ridge, sofit, or end vents. Even the
fiberglass insulation in the attic floor has little effect against this pressurized hot air.
Ultimately, the heat pushes through the ceiling to the living area below. The compressor in
your air conditioning unit is now working constantly to re-cool the hot air from your attic.
Imagine if you will trying to heat your home in the winter when you windows are open!

There are two types of attic fan: the whole house fan and the attic exhaust fan which comes in
a roof mounted version and a gable mounted version. The whole house fan is a large,
propeller fan that usually sits on the floor of the attic. The fan is framed in with lumber and a
hole is cut through the ceiling directly under the fan. A shutter is placed in the hole and this
shutter opens and closes automatically when the fan turns on and off. The fan draws air into
the house from the open doors and windows, creating a breeze to the fan, removing the hot
air in the path of that breeze and blows the air into the attic and then blows the very hot attic
air out of the attic through the vents, allowing the house to cool down naturally.The Gable
Fan mounts inside the attic behind the vent in the triangular end of the roof and the Roof
mounted version mounts on the out side of the house on the roof (kind of mushroom shaped
in appearance). Unlike a whole house fan the Exhaust Fans do not create a breeze through
the house, nor do they remove the hot air from inside the house. They also remove some
heat load from the air conditioning system and allow the house to cool off more rapidly,
especially at night.

Roof Fan

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