Free Tips Replacing weather stripping and seals on windows and doors: You will save between 5 and 10 percent on your annual heating and cooling costs. Install ceiling fans: During the summer months, have the fan set to go counterclockwise, creating a downdraft and making the room feel 8 degrees cooler. During winter months, set them to go clockwise, re-circulating hot air at the ceiling. Keep attics well ventilated: Ventilated attics are about 30 degrees cooler than unventilated attics. Properly sized and placed louvers and roof vents help prevent moisture build-up and overheating in your attic.