Whole House Fan Information

What is a Whole House Fan?

A whole house fan is a simple and inexpensive method of cooling a house. The fan draws cool outdoor air inside through open windows and exhausts hot room air through the attic to the outside. The result is excellent ventilation, lower indoor temperatures, and improved evaporative cooling.

Why use a Whole House Fan?

Before there was air conditioning, homes were cooled by relying on Mother Nature. Such things as shade trees, roof overhangs, and the orientation of the home itself all played an important role in maintaining a home’s livability during hot summer months. Whole house fans were often used to replace hot, stale inside air with cooler outside evening air drawn through open windows and doors. But with the advent of air conditioning systems, these low cost cooling methods, including the use of whole house fans, were gradually reduced to secondary strategies.
Now, with energy costs becoming increasingly important, people are taking a second look at these and other methods to reduce energy costs. Hence there is renewed interest in whole house fans.

What are the benefits of a Whole House Fan?

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.

Cooling Strategies

  • Morning pre-cool. Run a whole house fan in early morning to pre-cool furnishings and interior surfaces. Then before the temperature rises, turn off the whole house fan and close all windows and doors to trap the cool air in your home. This will delay the operation of your cooling system.

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.

Whole house fans are effective only when outside temperatures are lower than inside temperatures. They yield best results when outside temperatures fall below 80 degrees. In Sacramento, where the air is dry and delta breezes dramatically lower evening temperatures, whole house fans are an effective home cooling solution. Depending upon your specific circumstances, you may discover that a whole house fan can serve as your primary home cooling solution, letting you save your air conditioner for the very hottest days when outside air temperatures remain high.