After a comeback lasting nearly two decades, ceiling fans appear to have lost little of their appeal, despite some controversy over performance.
Fan styles available at most home centers and other fan dealers range from highly ornate Victorian models to contemporary designs with sleek, space-age lines.
Electric ceiling fans go back to the late 19th century, but their popularity tapered off with the wide use of air conditioning in the 1950s. The comeback began in the mid-1970s, when the Arab-led oil embargo made saving energy practical and chic. Fans are much cheaper to buy and operate than air conditioners.
Although many fan owners want them basically for decoration, energy performance is still a factor, and the fans often are touted as highly effective for summer cooling and an aid to heating in winter.
There is no question that air movement created by a ceiling fan can improve comfort in a warm room, but the cooling effectiveness depends largely on correct installation. A fan placed less than about 10 inches from a ceiling -- sometimes done to give extra head room -- loses much of its cooling effectiveness because there is not enough air above it for good circulation.
Also, ceiling fans should never be installed with the blades less than 7 feet from the floor, for both performance and safety reasons, so 8 feet is the minimum practical ceiling height to accommodate a fan installation.
Some experts say a fan gives its best cooling performance if the blades are 8 feet above the floor. Since 8 feet is the standard ceiling height in most homes, top performance is often impossible, if these experts are correct.
My experience has convinced me that ceiling fans are much less effective as coolers than whole-house fans, sometimes called attic fans (they are generally installed in attics), or high-powered window fans. These fans can be used to pull cool outside air into a home through partially open windows, while expelling warm inside air.
However, ceiling fans can be operated at the same time as air conditioners. Some fan users say they are able to set air-conditioner thermostats higher, and save money, because of the extra cooling action of the fan.
Air conditioners should never be used at the same time as whole-house or window-exhaust fans -- except in a room sealed off from the fan action -- since the expensively cooled air can be expelled outside.
There also is some controversy over the real value of ceiling fans in winter. Theoretically, if the fan's rotation is reversed in winter, it will recirculate warmed air from the heating system and help prevent collection of warm air at the ceiling.
Some experts say this works well only if the room's ceiling is at least 10 feet high and there is a well-insulated attic above. The ceiling fan in winter also should have a very low speed setting so it does not create a cooling breeze. Winter fans are said to work best in rooms where there is a great deal of heat buildup, such as in sun rooms or rooms heated with a stove.
Buying a correct fan for a room requires careful shopping. Here are some important points to remember:
* Measure the room's width, length and ceiling height. The measurements will help determine the correct fan size.
* Check the proposed location of the fan to determine if a safe installation is possible. Ideally, the fan should be secured to a solid, rigid framing member such as a ceiling joist. Special brackets also are available to mount fans between joists; a bracket can be installed through a small hole in the ceiling covering.
* An electric supply for the fan will obviously be needed. An existing junction box in the ceiling, such as that for a light, often can be used. If new wiring is needed, professional installation usually can be arranged when you buy the fan.Readers' questions and comments should be sent to Gene Austin, c/o The Features Department, The Baltimore Sun, Box 8263, Philadelphia, Pa. 19101