Submitted by: Carla Nemecek, Southwind Extension District Agriculture Agent
With summer temperatures on the rise, now is the time to look for alternatives to save a few dollars while trying to cool the home. K-State Research and Extension offers the following advice:
Can ceiling fans effectively reduce air-conditioning costs?
Any type of fan can be effective in reducing air-conditioning costs if the air movement helps occupants feel comfortable and results in increasing the thermostat temperature setting. If the air conditioning thermostat setting is not increased, there are no savings. The cooling effect of moving air can compensate for as much as a four-degree rise in temperature. Keep in mind, that during the heating season, the air movement caused by the fan will still have the same cooling effect.
How can I keep my home cooler in the summer without air conditioning?
The simplest, least expensive method to keep a home cool is shading walls, windows, and the roof. Interior shades are inexpensive and easy to install. Use pull-down or Venetian blinds in addition to regular window coverings. Window coverings should be light colored (white or beige). There are several ways to keep a home cool without overusing the air conditioner. Of these options, install shades first. Compare utility bills before and after the installation of shades. If satisfied with the savings, stop there, but if savings are not significant, look into other options. One option to consider is exterior awnings. They are more expensive than interior shades, but would be a great way to shade south windows. Natural shading is another way to block heat gain in summer. For example, plant broad-leafed trees on the south and west sides of the home. They shade a home in summer months and will let in sunlight during winter months when they have shed their leaves. Certain steps will help keep a home warm in winter and will help cool it during the summer. Insulated walls and roof reduce heat gain, just as they lower heat loss in winter. As a general rule, ceiling insulation should have an R-value of 35 to 45, and walls from 19 to 27. A light-colored roof also decreases heat gain. Use the above suggestions, coupled with circulating fans inside the home, and utility bills will be less than if air conditioning was the only cooling source.
Is it better to leave the fan running continuously with the air conditioner or to place it in the automatic position?
It is more efficient to leave the thermostat in the automatic position. The fan consumes only one-tenth the energy of the compressor, but when it runs continuously, the fan can cost up to $30 a month. This amount can be reduced by cycling the fan only when it’s needed. Additionally, the air conditioner will dehumidify the air only when the compressor is running. However, if the fan remains on after the compressor cycles off, some moisture on the coil will re-evaporate. This moisture must be removed during the next compressor cycle, which increases the energy consumption.
If air distribution is poor within the home or business and hot spots or very cold areas result, the fan can be run to even out the temperatures. However, the fan should be set to the auto position when the building is unoccupied. Even better, shut the air conditioner off or raise the thermostat setting when leaving the building.
Will I save energy by turning off my air conditioner when I leave home, or am I better off just letting it run?
If gone for four hours or more, more energy will be saved by turning off the air conditioner or turning up the thermostat. During the day, keep windows shut and close curtains or blinds on any windows that will be exposed to sunlight. The thermal mass of the house will probably keep the indoor temperature well below the outdoor temperature, and the house should cool quickly when the air conditioner is restarted. Use a programmable thermostat or timer to turn on the air conditioner 30 to 45 minutes before the expected arrival home. If the home is still warm upon arrival, turn on a fan to create air movement. Moving air can make the air feel about four degrees cooler than it really is.
For more information about energy savings, visit K-State Research and Extension on the web, www.ksre.ksu.edu