Western Washington’s hot and harsh late summer weather is sometimes described as our annual mini-drought. In August and September, temperatures are often hotter than 85 degrees and can climb into the 100s, as they did last year. That makes it difficult to keep a house comfortable.
The good news is that cooling your house in summer is much less expensive than heating your house in winter. Running central air conditioning, including heat pumps, on hot summer days can mean a higher power bill, but utility experts say such a system can cool an average-size house for an additional $1 to $1.50 per day. The calculation comes from evaluating utility customers’ power bills and looking at the increase in electrical consumption in July and August, said DuWayne Dunham, Clark Public Utilities energy counselor team leader.
Using an 1,100-kilowatt air conditioner — large enough to cool a 10-foot-by 10-foot room — for five hours per day, will cost about $13 per month.
There are strategies for keeping a home cool without using a heat pump or air conditioner, Dunham said. Here are some summer cooling tips:
• Use awnings or shades on the outside of south- and west-facing windows.
• Close curtains on south- and west-facing windows.
• Use small fans to create cool drafts. A ceiling fan running six hours per day all month costs 88 cents.
• Run the central air system on the “fan” setting to create a draft that helps you feel cooler. An added bonus is that the indoor air is being filtered.
• Open certain windows in the morning and evening when temperatures outside are cooler than inside to create a free draft and keep you cooler.
• Shade your house from direct sunlight to cut down on how hard your air conditioner has to work. Put deciduous trees on the south and west sides of your home. The shade also will protect your furniture and carpets from fading.
Using central air
Utility experts suggest that homeowners use a qualified technician to tune up central air systems every couple of years. According to http://www.energystar.gov, if a central air conditioning unit is more than 12 years old, replacing it with an Energy Star-qualified model could cut cooling costs by 30 percent.
A tune-up should include checking refrigerant levels and recharging if needed; checking for leaks; cleaning, oiling and inspecting the motor; checking the cooling coils and changing or cleaning the air filter. Make sure the outside heat pump unit is clear of grass, leaves and shrubs. It needs four to five feet of space to properly draw air.
Insulation in the ceiling or attic can help keep cool air inside your house and hot air out. With good insulation (R-38 level or close to it), homeowners should be able to get by for a couple of consecutive hot days without running the air conditioner at all. Adding more insulation will help with both heating and cooling.
Upgrade a cooling system
Clark Public Utilities offers financial incentives to add or replace an existing heat pump, and to do other energy-related home improvements. There are incentives for insulation and weatherization measures. In addition, homeowners may qualify for a federal income tax credit. Check with a Clark Public Utilities energy counselor for the latest information.
Energy Adviser is written by Clark Public Utilities officials, drawing on the expertise of energy counselors who provide conservation and energy use information to utility customers. Send questions to firstname.lastname@example.org or to Energy Adviser, in care of Clark Public Utilities, P.O. Box 8900, Vancouver, WA, 98668. Past topics are available at http://www.clarkpublicutilities.com.