Properly sized and placed louvers and roof vents help prevent moisture buildup and overheating in your attic. Because most of the energy that incandescent lamps use is given off as heat, use them only when necessary. Take advantage of daylight to illuminate your house. And consider switching to compact fluorescent lamps. These use about 75 percent less energy than incandescent lamps and emit 90 percent less heat for the same amount of light.
Many household appliances generate a lot of heat.
When possible, use them in the morning or late evening when you can better tolerate the extra heat. Consider cooking outside on a barbecue grill or use a microwave oven, which does not generate as much heat and uses less energy than a gas or electric range. Washers, dryers, dishwashers, and water heaters also generate large amounts of heat and humidity. To gain the most benefit, seal off your laundry room and water heater from the rest of the house. New, energy-efficient appliances give off less heat and use less energy.