How to Save Energy and Lower Your Summer Air Conditioning Bill
I’m not suggesting you sit around in the heat and swelter, but there are things you can do to keep your house cooler during the summer. Using these tips, our family usually doesn’t need the air conditioning until late August. This is when nighttime temperatures are consistently in the high 90s and the house can’t be cooled down.
Shade the windows
According to the California Energy Commission, 40% of the unwanted heat in your house comes in through the windows.
The effects of this solar energy can be reduced by covering south and west facing windows during the day. You do this by keeping the curtains shut or arranging blinds so that the light reflects back out the window. In areas of intense exposure, consider hanging a bamboo shade on the outside of the house. A bamboo shade on the outside of a west facing window can lower an interior room temperature by as much as 20 degrees.
If you don’t like the look of a bamboo shade or closed curtains, consider installing some reflective window films. These films reflect light and heat back outside where they belong.
Awnings are another alternative. Fabric or metal awning block the sunlight that reaches your windows, and can reduce heat gain by up to 77% on western windows and 65% on southern windows. (source:CEC)
Cool down the exterior
Trees are a terrific way of cooling down the house and surrounding yard. Trees and large shrubs can reduce air temperatures up to 20 degree, while providing shade and reducing water evaporation from your lawn. Hybrid poplar, Tulip poplar, and Weeping Willow are three varieties that grow nearly 8 feet a year.
Consider painting the exterior of your home a lighter color. This helps reflect heat away from the house.
Cooling the interior the old fashioned way
Back in the days before air conditioning, people had other ways to cool down their homes quickly and effectively.
During the day, summer heat builds up in the attic space of your home, reaching temperatures as high as 130 degrees. In the evening, this heat can radiate back down into your home. To pull the heat out of your home and attic, consider installing a whole house fan. House fans work by pulling in fresh air through the open windows of your home, and exhausting it out the ceiling and into the attic. From there, it’s pushed out of the attic through the roof or gable vents. We run our house fan at 7:00 in the morning to pull the cool morning air into the house before buttoning it up for the day. The fan is turned on again at 9:30 pm to remove warm air from the ceilings and attic. These fans can empty a house of unwanted hot air in less than 20 minutes and use a fraction of the electricity of an air conditioning unit.
If a whole house fan isn’t in your budget, box fans are also effective in removing warm air from your house. Place the box fan in an exterior window so it vents outside. For a large or two story house, you will need two or three fans. Open up the windows in your home, and let the fans pull the heat through the house and into the outdoors.
Ceiling fans are another great way to cool the house. Warm air rises and build up in the second story or along the ceiling. When operated in a counter clockwise direction, the fan blades push the air downwards where it can be cooled more effectively. The circulating air can also make you feel about 8 degrees cooler. Open the windows and let the fans push the hot air outdoors.
Use those heat producing appliances earlier in the day when the temperatures are cooler. Nothing heats up the kitchen more than the oven, and in the summer, I move my baking times to early in the morning and cook dinner outside on the grill. A small fan in the kitchen also helps to reduce the air temperature.
How to be energy efficient when using air conditioning
When the outside temperatures are so hot that the house can’t be cooled with fans, it’s time to turn on the air conditioning.
For a window mount air conditioning unit, be sure it is set up in window that is out of the direct light. To keep your air conditioning unit running at maximum efficiency, have it serviced in the late spring, before the summer warms up and service shops are busy.
If you own a central air conditioning system, regular service is also important to keep it running as efficiently as possible. Also consider keeping the thermostat set at 78 degrees and use floor fans to circulate the air. Replacing air filters regularly will improve efficiency between 1-2%.
When it comes time to replace the air conditioning unit, think about upgrading to one that is energy star rated for a 10% energy savings.
For more information about reducing your energy use in the summer, visit the web site of the California Energy Council at: www.consumerenergycenter.org/tips/summer.html
