What is a whole house attic fan and how does it work?
A. A whole house attic 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 white shutter is placed in the hole and this shutter opens and closes automatically when the fan turns on and off. The shutter allows air to flow from the house into the attic when the fan is running and keeps the attic air from entering the house when the fan is off. The fan draws air into the house from the open doors and windows, creating a breeze to the fan, removes 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 blades of these fans can be as small as 24″ diameter to as large as 48″.
