Blowing away the ceiling fan myths
Jack Hayes
Ceiling fans aren’t much understood beyond their common purpose-to circulate air for cooling comfort. They’re bought in the wrong sizes and mounted improperly in the wrong places. After that, they’re run at the wrong times, the wrong speeds-and even in the wrong direction. A few facts can help homeowners benefit more from their ceiling fans.
For example, in winter a ceiling fan can push heated air down from the top of a room to mix with cooler air at thermostat level. Feeling warmer, you can then roll your thermostat back and give the furnace a break. Because a ceiling fan runs at its slowest speed–in reverse–in the winter, on the average you’re only spending a 25-watt light bulb’s worth of energy to save considerable energy.
The actual benefit you get from this “destratification” will depend, for starters, on the size of the fan you’re using, the size of your home and height of your ceilings, and the amount of insulation in your walls. Energy experts say you can shave as much as 10 percent off your winter heating bill by moving the thermostat from 70 to 65 degrees F.
But the biggest energy assist you’ll get from a ceiling fan will come in the warmer months, when you can save as much as 25 percent on air-conditioning costs by moving the thermostat from 70 to 75 degrees F. Then the fan, running at maximum speed, will consume roughly the same energy a 100-watt light bulb does.
Unfortunately, manufacturers of residential ceiling fans have no agreed-upon standards, so there’s no easy way for consumers to judge or to compare performance between brands. “Buying blindfolded,” the way one observer puts it, is becoming more common as imported ceiling fans become more popular. One California-based industry consultant estimates that 90 percent of the 9 million ceiling fans shipped in the United States this year will come from foreign manufacturers.
So how do you know what you’re buying? “We get daily inquiries on ceiling fans,” says Dale Rammien, the director of the Home Ventilating Institute of the Air Movement Control Association. “We can only recommend dealing with companies that have a reputation.” Buying from dealers willing to back up their products is also wise. Three American-made brands dealers mentioned are Casablanca, Hunter, and Homestead.
But don’t expect dealers to know everything. Some will recommend the 42-inch ceiling fan for most applications. Others will recommend the 52-inch size. In fact, a fan’s job is to move air-and its ability to do that depends on the speed, the length, and the pitch of the blades, as well as on the number of blades.
A safe rule says 42-inch fans will move air comfortably in rooms as large as 10 ‘ x 15 ‘. Larger rooms need a 52-inch fan. There’s also a 36-inch fan for tiny rooms, including small kitchens. Dr. Fred Rohles, a former director of the Institute for Environmental Research at Kansas State University, recommends two fans when room size is larger than 10′ x 20’.
But for home application, the distance of the fan blades from the ceiling is the major concern. Because safety experts want fan blades at least seven feet above the floor, and because ceilings in most homes are only eight feet high, the industry introduced “hugger” ceiling fans. Experts wonder about the effectiveness of hugger fans. Byron Jones, an associate professor of mechanical engineering who studied ceiling fans with Rohles in the Kansas State “Comfort Lab,” says a 52-inch fan won’t do its job if the blades are less than a foot from the ceiling. A 42-inch fan can be squeezed within 8 inches of the ceiling-but no closer, Jones says. Thus, ceiling fans are of questionable use on low ceilings. Indeed, they do their best circulating in tall rooms, where expensive heated air gets trapped in the winter.
Today’s ceiling fan-whose blades attach directly to a motor shaft-was developed 100 years ago by Philipp Diehl, a New Jersey engineer who also designed a motor to fit the Singer commercial sewing machine. It was Diehl who engineered the Electrolier, an electric light chandelier with built-in fan.
Since then, not much has changed in the ceiling fan, except for solid-state technology, which allows more variation in lighting, speed, and on-off control. The most desirable fan feature, aside from appearance, is quiet operation. You can listen in the store, where dealers hang their fans in overhead assortments. To benefit you in winter use, your fan must be reversible, with variable speeds.
“I’ve seen people look with more scrutiny at a $15 toaster than a $150 ceiling fan,” says Ray Bishop, a salesman with Dan’s Fan City, a 125-unit specialty chain. About two-thirds of the ceiling fans shipped this year will sell for less than $100. Only 10 percent will sell for more than $150. Like most dealers, Bishop says you have to spend at least $65 for a fan that will run problem free for five years.
You should mount a ceiling fan where it’s going to do the most good. Above the dining room table where ceilings are low is a good fan location. “If you don’t feel the breeze, then there’s not going to be much creature comfort,” reasons Jerry Bogage, the president of Leading Edge, a Florida-based maker of commercial ceiling fans. Kansas State’s Byron Jones says you won’t feel much cooling beyond four diameters of the fan blade. Maximum cooling comes directly beneath the middle of the blade. If your budget has room for only one ceiling fan, then hang it in the room you use most.
Not that you’ll break an arm in the ceiling fan, but also consider safety when hanging it. One engineer for the Hunter line of ceiling fans accidentally threw his hands into the blades of a ceiling fan at home once. “It scared me more than anything else,” he jokes.
Finally, it’s not advisable to hang a fan over the head of your bed. Perhaps it’s just superstition, but a New York electrical contractor says he sleeps better with the ceiling fan over his feet instead.
COPYRIGHT 1987 Saturday Evening Post Society
COPYRIGHT 2004 Gale Group
