Whole House Fans


We’ve all enjoyed the Delta breeze and of course you know that most Sacramento mornings are pleasant and cool. It’s the middle of the day when temperatures soar! With a whole house fan you can cool your home with about 10% of the energy used to run your air conditioner.

A whole house fan is an easy and inexpensive method of cooling your home. The fan draws cool outdoor air inside through open windows and exhausts hot air through the attic, resulting is outstanding ventilation, cooler indoor temperatures, and improved evaporative cooling.


Before the advent of air conditioning, homes were kept cool by nature. Why does Sacramento have so many trees? Shade! Why is a roof overhang so valuable? Shade! Back before air conditioning fans were used to replace hot, stale inside air with cooler outside evening air drawn through open windows and doors.


A whole house fan can be used to reduce the need for air conditioning. Outside air temperature and humidity dictate times when the whole house fan would be favorable over air conditioning. If both methods of cooling are present, a seasonal use of the whole house fan (during spring and fall) may yield the optimum combination of comfort and cost.


The morning pre-cool. Use the whole house fan in early morning to pre-cool furnishings and interior surfaces. Before the temperature rises, turn the fan off and shut all windows and doors to keep the cool air in your home. This also delays the operation of your home’s air conditioning system.

The evening cool-down. Operating your whole house fan when the outside temperature drops below the indoor temperature will cause cooling. This will reduce your air conditioner’s run time, saving energy and money.

Depending upon your specific circumstances, you might find that a whole house fan can serve as the primary home cooling solution, letting you save your air conditioner for only the very hottest Northern California days.


Whole house fans are measured most often according to the volume of air they replace in cubic feet per minute (CFM), and by the drive mechanism—belt drive or direct drive. A fan that is properly sized for your home should make a complete air exchange in around two to three minutes. Five to ten air exchanges will cool not just the air, but the walls and furnishings as well. Interior surfaces contribute to heat buildup by absorbing heat throughout the day, and releasing it at night. Running a whole house fan for about twenty minutes will cool these areas sufficiently to make the house comfortable. Choosing the whole house fan that’s right for you will depend upon your needs, and the features you prefer.


  • Wall-mounted controls
  • Two speed/variable speeds
  • Belt or direct drive
  • Horizontal or vertical mount
  • Insulated louver covers (during winter when fan is not in use)

Whole house fans are inexpensive and usually pay for themselves in just a few seasons. For cost-effective cooling, they’re hard to beat. Ask your Huft Heating & Air professional if a whole house fan makes sense for you!