Saving Energy With Fans

(HIT) - The way most people look at it, there's no trick to beating the heat in summer-as long as you're willing to pay the price. There is an alternative, however.

More and more homeowners are finding that fans can provide them with the cooling effects they seek, while saving energy at the same time. There are a wide variety of fans currently available to homeowners, and each offers unique energy saving benefits. Properly selected and installed, these energy saving fans can create an indoor environment that saves money while helping homeowners stay comfortable all summer long.

Energy Saving Whole-House Fans

Foremost among energy saving fans is the whole-house fan. Situated near the center of the home, a whole house fan can be used during the summer months to draw in cooler evening air through screened windows and doors, creating a pleasant and comfortable indoor environment. The fan also produces breezes that can make the temperature seem two to eight degrees cooler than it actually is.

An effective cooling device at temperatures well into the eighties, the whole-house fan can yield substantial energy savings as it takes much of the cooling burden off of the air-conditioning system, yet can be operated for as little as one-tenth of the cost of air-conditioner operation. Useful in all climates, the whole-house fan can replace the air-conditioner in some areas of the country.

The Home Ventilating Institute (HVI), a voluntary organization of manufacturers of static and powered home ventilating equipment, offers a simple method for proper selection of whole-house fans. HVI labels displayed on member's products, show the certified capacity of the fan as measured in cubic feet of air moved per minute (CFM). To determine the necessary CFM rating for a whole house fan, multiply the interior square footage of the home (excluding garage, attic or basement) by three. In warmer, more humid climates, a larger capacity is needed, and the square footage should be multiplied by four in those areas. The resulting number is the CFM rating for the fan needed for the home.

It is important for the homeowner to provide sufficient static vents for the whole-house fan to function properly. To determine the necessary vent area, the CFM rating should be divided by 750. The resulting number will be the square feet of static vent area which must be provided.

Energy Saving Ceiling Fans

Ceiling fans—which have been around since the turn of the century—have enjoyed a rebirth in popularity recently, largely because of their decorative appeal. However, ceiling fans also offer significant cooling and energy-saving benefits to homeowners.

Research has shown that ceiling fans have the ability to make room occupants feel comfortable at temperatures up to 85 degrees Fahrenheit. The ceiling fan's ability to provide cooling effects at temperatures into the mid-80s is of notable significance in terms of energy and cost savings. The fans are extremely economical to operate and can yield substantial savings when used to supplement air-conditioning.

Ceiling fans are available with short-stem assemblies, allowing them to fit easily into rooms with standard eight-foot ceilings, with seven feet of clearance. Ceiling fans range in size from 36 to 52 inches across. Smaller models are designed for use in tight quarters such as hallways, small offices, stairways, dining rooms, apartments and small houses where space is at a premium. The larger fans are suited to living rooms, play rooms, large porches, basements, dens, and, thanks to truly silent operation, bedrooms.

HVI cautions consumers to be very careful in selecting a ceiling fan. The organization notes that some fans are built strictly as decorative items and are of almost no value as air-circulating devices. Consumers are urged to determine that a ceiling fan has been sturdily constructed to withstand the rigors of continuous operation before they make their purchase.

Energy Saving Attic Fans

During the summer months, as the sun beats down on the roof of a house, air in the attic can become extremely hot. As the heat builds up, it can penetrate to the house below, causing discomfort or putting an added burden on a home's cooling system. Further, attic heat build-up poses a threat to insulation and to structural materials, causing serious deterioration of these items. The problem continues in the winter when water vapor produced throughout the house rises to the attic and collects there. It can penetrate insulation, seriously impairing its efficiency, and can also cause damage to other materials in the roof and attic.

The ideal way to combat both unwanted intruders is with a powered attic space ventilator. Mounted on the roof or gable wall, the ventilator removes hot or moist air, replacing it with clean, fresh air from the outside. Equipped with a thermostat, the attic fans automatically come on whenever the attic temperature exceeds safe levels. In the winter, attic fans equipped with a humidistat activate automatically when moisture in the attic air reaches an unacceptable level.

To determine the necessary CFM rating for an attic fan, HVI recommends multiplying attic floor area by 0.7 (add 15% for dark roofs). The resulting number is the correct CFM rating for the fan needed to properly ventilate the attic. As with whole-house fans, the powered attic ventilators manufactured by HVI members are independently tested and certified, and the CFM rating is shown on the HVI label.

The combination of whole-house fans, ceiling fans and attic fans can go a long way toward providing relief from the summer heat, without worrisome utility bills. For more information about proper home ventilation, contact the Home Ventilating Institute Division of the Air Movement and Control Association, 30 W. University Dr., Arlington Heights, IL 60004 or visit the Institute online at www.hvi.org.


Courtesy: Home Improvement News and Information Center