Suggested date of release:
after October 10, 1999
Claudia Chandler (916) 654-4989
Media and Public Communications Office
(Second article in a 3-part series for October)
Keep Your Cool With Whole House and Ceiling Fans
California's summer of 1996 was one of the warmest on record. The Sacramento Bee on September 4, 1996, reported, "June, July, and August collectively marked the hottest summer in the capital city's history, and last month was the most sizzling August of all time in Sacramento."
It was also the summer that Sacramento resident Judy Grau's air conditioning bills went down.
"I attribute the savings to a whole-house fan I had installed early in 1996," Grau explained. "At the end of the summer, I compared that season's electric bills against those for the much milder summer of `95. I was pleasantly surprised with the results."
Grau, a mechanical engineer for the California Energy Commission, was meticulous in making her energy comparisons. "For the four-month period of June through September, I calculated the number of kilowatt/hours used each day. Despite much higher temperatures in `96, I actually used 318 kilowatt hours less electricity over those months. That's a savings of about $25, thanks I'm sure to the fan. "
Whole house fans are designed to operate in the early morning and after sundown, when the outside temperature drops below 80 degrees. The idea is to turn off the air conditioning and to turn on the whole house fan. With your windows open, fresh, cool air is drawn into your home, forcing out the hot air. Your entire house is then cooled by outside air, without the needed help of your air conditioner.
Because whole house fans use far less energy than air conditioners, they cut cooling costs. In fact, whole house fans typically use about one-tenth of the electricity of comparably sized air conditioners, and they are relatively inexpensive to install.
While whole house fans may be placed in a number of locations, the most frequently used spot is the hallway ceiling. Louvers normally close off the fan when not in use so that conditioned air doesn't escape through it. When the fan is operating, however, these louvers open, allowing air to be blown into your attic.
Attics can be brutally hot on a summer's day. When heat is absorbed by your walls and ceilings, attic temperatures can climb to over 150 degrees. Even if your ceilings are well insulated and your home is air conditioned, this heat can seep from your attic down into your home. A whole house fan, however, draws cooler outside air through your open windows and forces it through the attic and out through the roof vents. Your house and your attic are all cooled.
Whole house fans are very powerful and need sufficient attic ventilation to be effective. Your contractor can help you determine the correct fan size, capacity, and number of attic vents needed for your home.
Remember not to run your air conditioner at the same time you use the whole house fan, and to keep most of your windows open when it's operating. Opening windows not only helps the air circulation, but it also prevents fumes or flames from your gas appliances and fireplace from being drawn back into your home.
And for Judy Grau, those open windows offered another benefit from her whole house fan. She planted some star jasmine just outside her patio door. "Running the whole house fan with the patio door open brings in the wonderful fragrance when the jasmine are in bloom," she explained.
Ceiling fans - those twirling paddles that date from pre-air conditioning days - are also experiencing new popularity. Like whole house fans, they're inexpensive to operate and install, and they provide substantial savings on energy.
Used by themselves in mild weather, ceiling fans offer a low-cost alternative to modern air conditioning. Used in conjunction with air conditioning in hot weather, ceiling fans combine old and new technology to keep your family comfortable and your utility bills low.
When it's warm, the blades of a turning ceiling fan normally push air downward, causing cool air near the floor to travel outward and mix with air at the edges of the room. The process makes for more even cooling, and just the air movement in the room alone can make it feel cooler by four degrees or more! That means if you're using air conditioning along with your fan, you can set the thermostat at a higher than normal setting to save on energy.
The average ceiling fan uses about the same electricity as a 100-watt light bulb, so you can run one for just pennies a day. If you use it in the summer, however, keep in mind that it does little good to run it when you're not around. The fan really isn't cooling the room. Like a breeze on a hot summer day, it's the blowing air moving across your body that makes you feel cooler.
That same cooling effect caused by blowing air currents keeps many people from using their ceiling fans in winter. But most fans have a switch that changes the direction in which the blades turn. Instead of forcing air downward, the blades will push air up toward the ceiling, where hot air normally rises, and drive it back down around the edges of the room. That can result in more even heating. And better heat circulation will help to combat the problem of sweating windows that some homes experience in the wintertime because of condensation on the glass.
Ceiling fans can help solve other cold weather problems as well. "We have a two-story house with a big open stairway in the middle," said homeowner Robert Grow. "In winter, with the furnace on, the upstairs would get hot, while the downstairs - where the thermostat is - would stay cold. The furnace would run all the time."
His solution was to mount a ceiling fan at the top of his stairway to help mix the air more evenly. "It evens out the heat and gives the furnace more rest," said Grow. "It makes the house much more comfortable."
It's another example of how - in summer and in winter - fans can help you increase the comfort of your home while you decrease your monthly energy bills.
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This article is based on the California Energy Commission's Home Energy Guide, to be published early in 2000.
You can find additional information about energy in California on the Energy Commission's Web Site at www.energy.ca.gov.
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