University of Wisconsin - Extension

Many of us think of energy conservation as a winter issue, but energy costs can be high in summer, says a University of Wisconsin-Extension housing specialist.

"With news reports about the rolling blackouts in California and questions about supplies elsewhere, it makes sense to plan ways to stay cool and minimize energy now before the summer heat arrives," says John Merrill.

Space cooling is usually the biggest summer energy user. An increasing umber of Wisconsin homes re equipped with either window or central air conditioning, despite the fact that most state residents use air conditioning only 15 days a year.

Merrill suggests these ideas, regardless of whether you have air conditioning:

1. Start by keeping out as much heat as possible. This means making sure your house is well insulated. The attic should have a minimum r value of 38, which is roughly equivalent to 12 inches. Walls should have an r value of 19. In addition, you should keep windows and doors closed and window coverings closed during the heat of the day. It is particularly important to cover windows during periods when direct sunlight comes in.

2. When the sun sets and outside air is cooler than inside air, open windows and turn on exhaust fans to move the hot air out. This is particularly effective when the temperature differences between day and night are substantial. Some home owners install whole house fans to exhaust the warm air more quickly. One problem with whole house fans in northern climates is that they require careful sealing for the heating season or they can act as an unwanted chimney, sucking out expensive heat in the winter.

3. Manage your household activities to minimize heat and moisture production during periods when you are trying to cool the house. Be sure your clothes dryer vents outside. Better yet, dry your clothes on a line outdoors. Run dish washers at night and use exhaust fans after showering and while cooking. Use only the lights you need and consider using compact fluorescent bulbs, which produce much less heat.

4. Use fans to create air movement in rooms you are occupying. This won't lower the temperature, but it will increase comfort.

5. Use strategic ventilation at night for sleeping rooms. This means running a large window fan or high powered kitchen fan to exhaust in the evening and opening windows only in bedrooms where family members sleep. This creates gentle breezes in these rooms and makes sleeping more comfortable.

6. Another long-term way to make your home cooler is to plant shade trees on the south and west side of your home. Consider trees that drop their leaves in the fall so you can enjoy the winter sun.

If you have air conditioning, here are some additional ideas.

7. When you are using air conditioning, it is worth closing your house up even more by closing storm windows.

8. Check filters to be sure they are clean. For central air, the filters are the same ones you check in the winter and are part of the furnace. For window units, they are behind the grill. Dirty filters limit air flow and force equipment to work harder and use more energy.

9. Use your set back thermostat so that the house is warmer when you aren't home during the day but cooler when you come home. In general, keep the thermostat set as high as you can tolerate. Using portable fans to create air movement can help you tolerate higher settings.

10. When you are running air conditioning, turn off dehumidifiers. The air conditioner is operating as a dehumidifier and may be lowering the temperature to the point that a conventional dehumidifier won't operate efficiently.

11. Close off rooms that you aren't using and the cooling ducts to them to focus the cool on the rooms that you are using.