A solar-powered attic fan assists with home cooling by pulling hot air out of the attic, either through a roof vent or a gable vent. A photovoltaic panel saves money by generating electricity for the fan.
ILLUSTRATION: KEITH WARD
Fans of various type are one of the simplest ways to achieve home cooling during the summer. In addition to promoting air flow, which makes us feel cooler, properly located fans can purge heat from a house and draw in cool outside air. Moreover, fans use less energy than central air conditioners and evaporative coolers, and are less expensive to install. By reducing or eliminating the need to use air conditioning, fans save money through dramatically lower utility bills.
Follow these links for information on specific fan types:
Use a Ceiling Fan for Simple, Efficient Cooling
Cooling Your Home With a Solar Attic Fan
Whole-house Fans: Easy, Low-cost Cooling
What Will You Save?
A regular attic fan uses electricity, but saves about 10 percent on air conditioning costs by keeping your attic (and, as a result, the living space below it) cooler. Solar-powered attic fans have a higher initial cost.
A ceiling or portable floor fan will cut your energy costs if you have central air conditioning — if you raise the thermostat setting. For every degree you turn it up, you will cut 7 to 10 percent from your cooling costs.
Using a whole-house fan — instead of air conditioning — when the temperature cools off in the evening and early morning hours can save significantly on energy costs. Not only does a whole-house fan cost less to run than air conditioning, but it can cool a house down in just a few minutes, after the outside air temperature has decreased.
What Will it Cost?
Ceiling and Attic Fans
Cost Estimate: Installation of two ceiling fans and two solar attic fans, controls and wiring.
Ceiling fans range from: $45 to $700
Attic fans start around: $90
Solar attic fans cost between: $300 and $700
Cost for materials only: $750
Contractor’s total, including materials, labor and markup: $1,500
The materials cost (whole-house fan and other supplies) can be anywhere from about $300 to more than $1,200
Cost Estimate: Installation of a whole-house fan, including a high-quality 36-inch-square, 6,500-cubic-feet-per-minute (cfm), two-speed fan with switch, wiring and new circuit breaker, as well as an allowance for framing and drywall repair materials.
Contractor’s total, including materials, labor and markup: $1,450
Costs are national averages and do not include sales tax. If you have a contractor do several small projects at once, you’ll save money overall.
This article is excerpted from Green Home Improvement by Dan Chiras. Dan teaches workshops on renewable energy and green building through the Evergreen Institute