Attic fans are often confused with whole house fans. They really are very different devices, and have different goals. It’s important to understand what each does as well as their differences, so you can choose the right device for your home.
An attic fans is typically installed in the roof of a house or building to remove hot air from the attic. An attic fan only removed hot air from the attic, rather than the entire living space. Because heat rises, on a hot day, the temperature in the attic can top 100 degrees. The attic air may be 20 degrees or higher than the temperature outside or within other parts of the home. Most experts tell us that attic fans help to reduce energy costs, while also improving ventilation. Attic fans may also be beneficial in extending the life of other major house components, including insulation, roof framing, electrical wiring, venting to name a few. An attic fan can draw less than 300 watts, making it a true energy efficient device. On hot days, an attic fan can reduce the temperature on the upper floors of your home by as much as 10 degrees. Adding a humidistat to your adding fan helps to reduce moisture to keep your attic dry in the colder months.
There are two main types of attic fans: electrical and solar powered. Electric attic fans are less expensive and are more forceful. Solar powered attic fans are not as cheap, but they are environmentally friendly. High quality attic fans have waterproof integral flashing that integrates with roofing materials.
Whole House Fans
Like an attic fan, whole house fans remove hot air from a home or building. However, instead of simply removing hot air from the attic, a whole house fan removes hot air from the entire house. A whole house fan is an inexpensive and simple way to cool an entire home, often without the need of a central air conditioner. With a whole house fan, cooler air is drawn inside throughout open windows. Warmer air is then forced up into the attic, then out of the house. Whole house fans provide ventilation, improved evaporation and lower interior temperatures. Whole house fans are energy efficient and reduce your energy costs, with estimates of costing only one-tenth as much as running air conditioning. Combining a whole house fan with a ceiling fan keeps homes adequately cool in many climates.