How To Use Your Whole House Fan
Updated: Mar 24
Whole house fans are the most efficient and cost-effective way to create a healthy, comfortable environment in your home. Many are designed to be self-sustaining, run for pennies an hour, and require little to no maintenance. Nonetheless, knowing how your fan works — and how to use it — will ensure you're getting the most out of your whole house fan system, maximizing the benefits and prolonging the life of your fan.
How It Works
Your whole house fan is ready for action anytime the temperature is cooler outside than it is inside your home or attic space. Simply open a few windows 4-6 inches to let the cool air in, turn your WHF system on and enjoy the nice, cool breeze as fresh air travels through your home and out your attic. That's it! With proper ventilation, a whole house fan system can completely exchange the air in your home in as little as 3-4 minutes, replacing warm, stale indoor air with a cool and comfortable environment for hours — even during the hottest times of day!
How To Use It
Time Your System: Press the button on your timer to cycle time periods, or press and hold to run indefinitely.
Manage Air Intake: It is vitally important that you open enough doors and windows to support the airflow generated by the fan. Use the ceiling grate as a reference to open windows and doors.
For QuietCool fans: At least 1x the area of the grate on low and 2x on high for targeted cooling. For general cooling, double the open areas of fans.
For Triangle fans:
42" fans need 25 square feet of opening.
36" fans need 18 square feet of opening.
30" fans need 12 square feet of opening.
24" fans need 8 square feet of opening.
Direct Airflow: This can be achieved by opening specific doors and windows. If you want to direct a strong airflow through your bedroom, for example, open windows in that room only. It is important to ensure you have provided enough air intake with any combination of window openings, but keep in mind more openings will result in weaker breeze coming from each window.
Optimize Usage: For the best results, run your fan first thing in the morning for at least 10 minutes to bring a cool breeze through the house and into the attic, flushing out heat or stale air from the night before. Then, close the windows, doors and blinds on the sunny side of your home, and turn your fan off as the outside temperatures rise. (If you want to run the fan during the day to push air out of the attic, or in tandem with your A/C unit, we suggest directing airflow from either the basement or the shady side of the home for the best results.) Your fan may be used on milder days year-round to bring fresh air into the home, or to draw odors, smoke and other pollutants out of your living spaces.
In the evening, when outside temperatures begin to fall, open the windows on the shady side of your home and turn your fan system back on. You will get better cooling results for the next day if you run your fan longer into the night, but running the system while you sleep may cause you to become too cold, so set your fan timer accordingly. Experimenting with your fan and home openings will maximize both your comfort and your fan’s performance.
Maintain Your Fan: Your fan has sealed bearings and should not require any maintenance besides occasionally cleaning the dust from your ceiling shutter, but preventative maintenance by our technicians can help reduce the likelihood of your fan needing service during the high season. If you get a new roof installed on your home, make sure that the new roof provides the same amount of ventilation as before. Any reduction in ventilation will compromise the ability of your fan to move air, make the fan run louder, shorten the lifespan of the fan, and potentially void the manufacturer warranty. A new roof may be a good opportunity to install uniform vents on the roof or improve your fan’s ventilation, but don’t assume your roofer will know the right ventilation for your fan. Please contact us with any questions specific to your fan during a roof replacement.
With a little know-how and proper ventilation, your whole house fan system will at peak performance, reducing energy costs and maintaining a healthy, comfortable home for years to come.