Updated: Jun 14
Attic ventilation plays a key role in keeping you, your loved ones, and your home as happy and healthy as can be. Superheated air, indoor air pollutants and moisture build up are a constant threat to your home and health, causing undue strain on your home cooling systems (and wallet!), respiratory issues, and expensive structural damage to your home — yikes! Attic fans and vents are specifically designed to expel hot air, pathogens, and moisture buildup from your attic automatically, improving indoor air quality and comfort in a matter of minutes and saving you tons of money in costly repairs. All residential home builds are required to include a certain amount of attic ventilation (measured in Cubic Feet per Minute of airflow, or CFM). But while your home has some attic ventilation, is it really enough?
Unfortunately, the answer is probably not — especially if you are or planning on using a whole house fan, air conditioner, swamp cooler, or other HVAC system on a regular basis.
Some whole house fan installers will try to convince you that you don't need additional attic ventilation to use a whole house fan — this is simply not true. According to the U.S. Department of Energy, you'll need as much as 2 to 4 times the normal area of attic vents (or about one square foot of net free area for every 750 cubic feet per minute of fan capacity. The air in Colorado's high altitude climate is about 75% less dense than it is a sea-level, so fans here need about 1 SqFt for every 1,000 CFM of airflow to operate ) for your whole house fan to operate as efficiently as possible.