ROANOKE TIMES
Copyright (c) 1996, Roanoke Times
DATE: Sunday, September 15, 1996 TAG: 9609180007
SECTION: HOMES PAGE: D-1 EDITION: METRO
COLUMN: HINTS FOR HOMEOWNERS
SOURCE: STEVE ELDER
In the average home there are usually five different types of fans: kitchen range-hood fans or wall fans, bathroom fans, attic fans, whole-house fans and ceiling fans.
Due to improper installation or misunderstood purpose, many of the fans I see as a home inspector are ineffective or nonfunctional. However, they can be a big help to your comfort level if installed and used properly, so here is the proper fan usage.
Range-hood fans are the small fans in the metal hood over your stove that are supposed to remove the olfactory evidence of dinner perpetration. They will do just that if they vent to the outside like the wall or ceiling fans you see in older kitchens. If they are the ``ventless'' kind that are not ducted to the outside, then they simply pull the air through a mesh combined with a charcoal filter and blow it back into your face as you stand at the stove. Then why are so many houses built nowadays with ventless kitchen fans? Come on now, you already know the answer to that one.
Bathroom exhaust fans are required in bathrooms without an operable window, but are a good idea for all bathrooms. Their purpose is to exhaust excess moisture and stale air from bathrooms, and they are required by code to be ducted to the outside. I frequently see these fans ducted into the attic space, particularly if they have been installed by the homeowner as an afterthought.
Bathroom fans that exhaust into the attic can lead to condensation problems during cold weather, especially if the attic is poorly ventilated to begin with. You can get el cheapo bathroom fans for as little as $11. However, by spending a little more you can get a fan that is much quieter and can also be used as part of a house ventilation system. (Tip: If you get a good fan and control it with a separate switch, you won't be tempted to unplug it, as many people do because they can't stand the racket.)
Attic fans are the ones that are installed through the roof or over a gable vent. Their purpose is to remove the hot air from the attic only. Some experts believe that if the attic is properly ventilated with properly sized gable vents or a combination of soffit and ridge vents, then exhaust fans aren't necessary. However, from long experience I can personally attest that even properly ventilated attics may reach 130 degrees on a hot day; and poorly ventilated attics get even hotter. Exhausting this hot air with a fan will reduce the temperature in the attic to that of the ambient air, thus preventing attic heat build-up that radiates back into the house until well into the evening.
The typical cost of having an attic exhaust fan installed is around $150 to $175, but the costs of your central air-conditioning can be reduced by as much as $20 a month. Even if you don't have central air, attic fans will make the second floor much more habitable in the summertime. Make sure that they are controlled by an adjustable thermostat (set at 90 degrees) and that a cutoff switch is installed near the attic access hatch so you can turn them off for the winter.
Whole-house fans are typically installed in the top- floor ceiling and are designed to cool the whole house. These fans are to be used instead of air conditioners, not with them. There is little point in turning on a whole house fan if the air you're pulling into the house is also 90-plus degrees, so their use is actually limited. They are intended for situations where the day has been warm but the evening is considerably cooler, namely on fall and spring evenings.
Opening several windows and turning on a whole-house fan will exhaust the warm air that has built up during the day and replace it with cool evening air at a significantly lower cost than running central air conditioning all day long. Because they are large and noisy, whole-house fans are usually operated only for 10 or 15 minutes at a time, which is normally adequate.
They should be controlled by a timer switch mounted high on the wall out of reach of little fingers. Having a timer switch also prevents occupants from mistaking it for a light switch and turning the fan on inadvertently. The fan should be installed in the top-floor hall ceiling. Be sure to have a separate hole cut, so that the fan unit does not block your only access to the attic.
Finally, whole-house fan housings do not seal very tightly, so it is a good idea to place batts of insulation over them for the winter months to prevent heat loss into the attic. Also, have a separate cut-off switch installed in the attic and turn it to the ``off'' position to prevent accidental operation after the unit has been winterized.
Ceiling fans have been around for a long time and are the true ancestors of air conditioning. They cool by simply stirring up the air in a room. Contrary to popular belief, it doesn't make much practical difference in an average-sized room whether the fan pulls air up or pushes it down ; it's the air movement that is important. In a large room with a high ceiling, however, you should keep the fan off if you're running the central air during the summer. The warmer air is near the ceiling; why push it down where you are.
In the winter, turn the fan in a large room on at a low speed to circulate the warm air down to people level. If you don't have central air, then ceiling fans will raise your comfort index noticeably. Many people get by quite nicely with them and have done so for over a century.
If you're going to buy ceiling fans, do not scrimp by purchasing cheap units. The good quality fans cost more, but they're worth it because they're better balanced and quieter.
Steve Elder is a Roanoke home inspector. Questions and comments may be sent to him in care of The Roanoke Times, P.O. Box 2491, Roanoke, Va. 24010-2491.
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