Options for powered attic vents include the traditional store-type fan that can require extensive maintenance, the solar-powered vent and the electric vent. The vents are designed to exchange the often hot attic air with cooler air drawn into the attic through the eaves. Another type of powered attic vent is a wind-powered type that operates virtually free of cost. The wind-powered attic vents use wind to turn a small fan inside the vent to draw stale air out of the attic.
The air in an attic should be replaced at least once every six minutes during summer months to prevent moisture, condensation and mold. One method of doing this is to install powered attic vents into the roof of the building. While a gable vent appears to be a good method of venting an attic, the flow of fresh air is limited to the area of the gable, so there is typically insufficient air circulation through the attic. There are four types of powered attic vents that actually draw fresh air from the soffit and force it out of the roof.
The store type of powered attic vents consists of an electric motor that spins an exhaust fan via a rubber belt and pulley system. The fan motor can be wired to a thermostat switch programed to come on at a certain temperature. This type of vent is typically noisy and requires a lot of maintenance. The drive belt requires frequent replacement and the fan requires a hole to be placed in the structure to be used as an exhaust vent. This opening allows cold air to enter the building in winter months as well as the warm, heated air from the furnace to escape.
Each type of powered attic vent has its pros and cons. Solar-powered attic vents may often save money on utility bills, however, the vent can often stop running as the sun sets, leaving an attic that has not sufficiently cooled down. Electric roof vents are typically wired to a thermostat switch and do a good job of circulating the air while remaining fairly quiet. Wind-powered attic vents work well while the wind is blowing, however, on some of the hottest days, the wind does not blow. This leaves the attic very hot and can cause an air conditioning unit to work overtime, and in many instances, it could eliminate any potential energy savings from using wind-powered vents rather than electric vents.
