My family likes to be cool during the summer, but I worry about the electric bill. Are there ways to use ventilation to stay comfortable without running the air conditioner as much?—Michael A.
Proper ventilation can keep you feeling cooler and reduce electric bills for air conditioning. The actual air temperature in your home is not as important as how you feel. Human nature being what it is, people often perceive their comfort level by the temperature setting. Tell them it is lower and they think they feel cooler.
Setting your central-air conditioner thermostat just 2 degrees higher can reduce your cooling costs by up to 5 percent. Moving air can feel many degrees cooler than still air at the same temperature. This is partially due to the fact that more heat is transferred from your skin to moving air. Also, as air flows over your skin, moisture evaporates even if you are not noticeably sweating, and this feels cooler.
There are two types of ventilation.
One is moving indoor air with the windows closed. In addition to making you feel cooler, it can balance room temperatures in your house, and actually lower the temperature in some rooms and raise it in others.
The other type of ventilation is bringing in outdoor air at times and shutting off the central air conditioning. Both have their places and can be effective.
Installing a ceiling paddle fan is what is commonly thought of as indoor ventilation and does work well. Run the ceiling fan on medium or high speed with the air blowing down to create a direct breeze on your skin. In winter, reverse the blade rotation and run it on low speed. This will gently circulate the air around the room without creating a breeze.
Although running an electric fan can make you feel cooler, it will not cool the room. On the contrary, it actually heats the room air because all the electricity it uses ends up as heat energy. When no one is in a room to take advantage of the comfort effect of the breeze, always switch off any electric fan, including ceiling fans. Each kilowatt-hour of electricity used by a fan produces 3,414 Btu of heat that your central air conditioner has to remove.
Small personal fans can be effective at creating a breeze directly on you while you sit in a chair or work at one location.
New small personal fans are available that do not have a protective cage over the blades. The blade material is soft and will not harm your skin if you bump it while it is running. By not having a cage that creates resistance, the airflow is more efficient. The blades are also easy to clean. Clean blades flow more air and use less electricity.
Setting your central air conditioner blower to “on” can help balance room temperatures, but it will not create much of a cooling breeze. Standard blower motors are very powerful and running one continuously will heat up the air.
Natural outdoor ventilation is effective and free. When you open double-hung windows or an entry door with a storm/screen door, open both the top and bottom sashes a little. This creates a natural vertical airflow, even on a still day.
Sit by a window on the windward side and on the first floor if you have a two-story home. Open the window just a little. Open the windows much wider on the other side or on the second floor. This will create a higher velocity of the incoming air for a stronger breeze.
The following companies offer air ventilation products: Holmes Products, (800) 284-3267, www.holmesproducts.com; Hunter, (888) 830-1326, www.hunterfan.com; Kaz, (800) 332-1110, www.kaz.com; Vornado, (800) 234-0604, www.vornado.com; and Windchaser Products, (800) 405-2943, www.windchaserproducts.com.
Mail requests and questions to James Dulley, Kentucky Living, 6906 Royalgreen Drive, Cincinnati, OH 45244, or visit www.dulley.com.