Updated: Mar 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.
You can only bring in as much air as you can discharge out of your attic vents... Air, like water, takes the path of least resistance. The air must go somewhere, and if there is not enough venting, the air will go back down the walls. — QuietCool Manufacturing
Bottom line: without enough airflow through your attic, your whole house fan will not operate properly and will likely malfunction — don't fall for misleading information from your whole house fan installer!
Different from whole house fans, air conditioners, evaporative coolers and furnaces work hard to recirculate treated air throughout your home to mimic comfortable temperatures, but they can only do so much. Regardless of the season, hot air rises the highest levels of your home throughout the day and gets trapped inside your attic, forcing your home cooling systems to work overtime and raising your utility bills. Adding additional attic fans and vents to your existing home cooling system removes that demand by as much as 90% by automatically pushing that trapped air our of your attic and dramatically reducing your home energy costs. During the winter months, attic fans and vents protect your attic and roof from ice damming and moisture buildup as snow and ice continuously melts and refreezes.
Attic fans and vents come in a variety of sizes, makes, and models, with everything from passive and hard-wired vents to solar powered fans. The size of your home as well as the amount of additional airflow needed will determine the best ventilation products to suit your needs — just remember, the more vent area you have in your attic the better, especially when installing a whole house fan or air conditioning system.
Need more attic ventilation in your home?
Contact Colorado Home Cooling & Daylighting — Colorado's top-rated attic fan installer. With no-contact free estimates, industry-leading products, and unmatched customer service since 2003! All attic fan sizes, makes and models in-stock and available for install in a little as one week!