Fresh air is pulled in from your soffits and/or roof vent, creating a draft through your attic. This will use more energy and make your air conditioner work harder, which will increase your summer utility bill. Is It Ever Helpful To Use A Powered Attic Ventilator - Energy Vanguard In addition to reducing the attic temperature attic fans also helps to remove moisture from the attic thus preventing the build up of molds. Do attic exhaust fans really work . Most fans cannot keep up. Solar attic fans work by pulling in the cold air from the soffits and pushing out the hot air that has accumulated at the top of the attic. Theory behind attic fans is they work on the principle of drawing hot air out of the attic and pushing it outside through the gable or roof levels. The use of an attic exhaust fan can reduce this energy loss to a great extent. Attic fans expel super hot air from the attic and suck in cooler outdoor air instead. They can also help cool the second floor, and in ...