Whole House Fans

Whole house fans work by pulling cool outdoor air into your house. They also push warm indoor air out of your house. They can replace the need for an air conditioner in milder climates. They can be used in conjunction with air conditioners in hotter climates. The use of whole house fans will cut your energy bill. Another benefit is that they cool very rapidly by taking in large amounts of air.

Whole house fans draw cool air in through windows and doors and pushes warm air out through attic vents. They are most efficient in the early hours of the day and the cooler evenings. A whole house fan can only cool your house to the outside temperature. They work best in climates that average 70 degrees.


The usefulness of whole house fans is limited in areas of high heat and humidity. They do not dehumidify the air. A dehumidifier is probably going to be necessary.

Another drawback is that they will pull in dust and pollen. This could be a serious problem for people with allergies or sensitivities to dust. Whole house fans tend to be noisy. The only way to avoid this is to invest in a high-quality model.


There are two traditional, well-known and trusted types of whole house fans. The first is called a direct-drive fan. On this type the fan blades are directly attached to the spinning shaft of the motor. These fans are the least expensive and can be found at just about any home-improvement store.

The second type is called a belt-driven fan. This type uses a pulley to turn the blades. This type is somewhat more expensive than direct-drive models. There are also modern models that are quite different and promise more efficiency but are also very expensive.

There are some other differences between belt-driven fans and direct-drive fans. A belt-driven fan will rotate more slowly but produce more air flow. They are more powerful. They are also more quiet, more durable and easier to maintain and repair if needed. The better models will have a well insulated housing, a higher quality motor and more balanced blades.

Modern models of whole house fans are easier to install, are sealed and more quiet. However they lack the proven reliability of traditional types.

Sizing and Options

Whole house fans typically come in 24, 30 or 36 in. models. The capacity is determined in cubic feet per minute (cfm) of airflow. To determine the right fan for your house consult a professional contractor for help.

There are other options to consider in determining the right model for you. Choose one that is well insulated and has a tight fitting seal cover; besides insulating, this will cut down on noise.

Pick a model that has multi-speeds. They will usually have at least a high and low speed setting. The high setting allows quick cooling. The low speed allows consistent circulation.

There are many other different control options. Pull cords, power switches, automatic shut off and timers are a few.


Installing a whole house fan requires detailed knowledge and advanced level electrical skills. You should hire a professional electrician. If you choose to install it yourself, be very careful and follow the manufacturer’s directions precisely.