A whole house fan is a simple and inexpensive method of cooling your living space while lowering the use of your air conditioner. On a hot day, heat builds up within your home, and the A/C kicks on. But what happens when the air outside grows cooler, say late afternoon and evening? Why not shorten the use of your A/C by drawing this cooler air inside? There may even be times when you don’t need your A/C at all.
This results in substantial savings. For example, the Office of Building Technology – U.S. Department of Energy, says:
A large 18,000 Btu/h window unit air conditioner with an energy efficiency ratio (EER) of 8.8 costs more than 17¢ to operate for one hour. By contrast, a whole house fan has a motor in the 1 / 4 to 1 / 2 hp range, uses 120 to 600 watts, and costs around 1¢ to 5¢ per hour of use.”
What is a Passive Cross-Breeze?
Sometimes when you get home and find there is a nice cool breeze outside, but the heat inside has built up, you throw open the windows. This is passive cross-breeze in HVAC speak. However, unless you open several windows and get a strong breeze, it could take all night to cool the internal thermal mass of air. Perhaps you’ve experienced this in the past, when you lived without an air conditioner, or say at a vacation cabin.
What Happens When you Aren’t Home During the Day?
Before, when you left your air-conditioner turned off and returned home in the early evening, it was 90 – 100 degrees inside. With the whole house fan running, and pulling out the accumulating hot air, your home temperature may be as low as 70 – 78 degrees during the same kind of weather.
Quiet Cool Manufacturing, Inc. is one of the makers of high quality and reliable whole house fans. Their suggested use is to start by cooling the area which you most occupy, such the kitchen and family areas during early evening. This is where you would want to start opening a window or two and turning on the whole house fan. As the cool air is drawn inside, the hot air is pulled out through the attic and roof. Next open windows a bit in your bedrooms. Quiet Cool recommends not opening too many windows, or too wide. After a few tries, you’ll get the desired balance.
Do I Need a Basement Ventilation Fan?
These are most useful in preventing stale, musty and humid air. High humidity can lead to foul odors and mold growth, and even cause damage to some things you may have stored in the basement area.
Whole House Fan vs. Attic Fan Misconceptions
In the 1970s people began referring to the old ‘helicopter’ whole house fan as an attic fan. But there is a big difference between an attic fan and a whole house fan.
A whole house fan exhausts or draws air from the home, into the attic, and out the attic vents.
An attic fan is a fan that exhausts air strictly out of the attic, and not the home living area. There are many types of attic fans such as attic gable fans, roof mount attic fans, and solar attic fans.
How do These Compare to a Gable Fan?
Rather than bringing fresh air in through your windows, a gable attic fan is designed to remove the hot, stale air from the attic of a home. You will feel the benefit of this fan mostly in your cooling bill. Since gable fans remove the hottest air in the home, your air conditioner will be more efficient, and you may be able to run it less while still effectively cooling your home.
Could you use a Garage Exhaust Fan?
Do you do a lot of work in your garage on vehicles, painting, wood crafts, or a million other home projects that produce particles or fumes? A garage exhaust fan pulls the polluted air outside, leaving fresh air indoors. When your garage is attached to the house, you don’t want this poor air quality entering the home, making your family sick. By venting out the hot air, the garage will feel cooler when you are using it as a workspace. Also, the fresher air will extend the life of your cleaning chemicals and gardening products.
Abel Heating and Cooling Can Help
In selecting the correct whole house fan to have installed in your home, Energy.gov http://energy.gov/energysaver/cooling-whole-house-fan advises: “Whole house fans should provide houses with 30 to 60 air changes per hour (varies with climate, floor plan, etc.—check with a professional to determine what is appropriate for your home). The air-change rate you will choose depends on your climate and how much you will depend on the whole house fan for cooling.”
In some climates, using a whole house fan can substitute for an air conditioner most of the year. Think of the savings!
Interested in learning more about having a whole house fan, garage exhaust fan, or attic fan installed? We’d be happy to help you make the best selection for the size and comfort of your home.
Call us at 952-472-2665 or Contact Us