Solar attic fans use power from a solar panel to exhaust air from the attic and reduce the temperature. By increasing the ventilation in this normally hot area, they pull cooler outside air into the space while exhausting hot air from inside it.
Reducing the attic temperature helps to reduce the cost of air conditioning a home. The exact amount of savings depends on several factors, including the cost of electricity in the area, the volume of the attic and the amount of ceiling insulation. However, most homeowners recover the cost of insulation within two to four years, according to Everything Solar.
Many homes have existing vents near the ridge or in the gables of the roof. However, these vents operate using passive ventilation. Since hot air rises, it escapes using the chimney effect. However, adding a solar attic fan increases the speed at which the air exchange takes place and keeps the attic cooler. Because the units are solar powered, there is no need to add additional wiring to power them.
As of 2015, a Federal tax rebate is available for homeowners who install solar attic fans. The rebate covers 30 percent of the purchase price and installation fee for solar fans. In order to claim the rebate, consumers file IRS Form 5695 with their annual tax return.