What is a whole house fan? A whole house fan is typically installed In the best location to suit your needs and it is designed to draw in cooler air from outside.  We’re fortunate to be located in California’s central valley, since it has a near-perfect climate for use of a whole house fan. Much like you figure an attic fan would operate, a whole house fan then pushes hot air out of the attic. Under ideal conditions, you can open your windows during cool mornings or evenings, turn on the whole house fan and cool your home without the use of air conditioning.