ROANOKE TIMES
Copyright (c) 1996, Roanoke Times
DATE: Sunday, July 7, 1996 TAG: 9607090002
SECTION: HOMES PAGE: D-1 EDITION: METRO
COLUMN: Hints for Homeowners
SOURCE: STEVE ELDER
``Sick building syndrome'' has been a familiar phrase in commercial real estate for a number of years.
What it specifically refers to is the buildup of indoor air pollutants emitted by such sources as carpeting, formaldehyde outgassing from commercial plywood and particleboard furnishings, industrial strength cleaners, office equipment, etc. Other major contributors include poorly maintained air conditioning systems, poor design (such as locating the building air intake over the dumpster in the alley - don't laugh, it has happened) and inadequately sized ventilation equipment or over-populated offices.
Now that rising energy costs have led to greatly tightened construction of new homes, it is possible to have poor indoor air quality in your home as well. The problem can be caused in homes by emissions from furnishings, poor system maintenance (not changing furnace filters), pets, smoking, cooking and poor housekeeping. ``Wet'' lifestyles can also contribute: whirlpool tubs and having lots of plants can make the indoor humidity excessively high, thus promoting the growth of molds and other allergens. Damp basements can have a similar effect. In the days of looser construction, a certain amount of air seepage usually kept the indoor air supply fresh enough; but with the tightness of recent home construction, infiltration ventilation may no longer be sufficient.
So what is a poor soul to do? First you're told to tighten up your home to save energy, and now you're told that your health could possibly suffer as a result. Fortunately, solutions to this apparent dilemma do exist. Which one is right for you depends on the size and siting of your home, your lifestyle requirements and the climate in your area. Assuming that you have a new home or have tightened up your house and assuming that you have made proper provision for combustion air intake to your furnace and water heater, there is some new technology that can help.
The experts generally agree that homes should be weatherized as much as possible. Sealing your home along the guidelines suggested in my last article will not only save energy but will also enable you to control the influx of fresh air. There are two methods for providing your home with fresh air. The less complicated and less expensive method involves installing the new breed of super quiet, energy efficient bathroom exhaust fans in conjunction with fresh air inlets.
The Panasonic FV series is highly regarded by ventilation experts for its quietness and efficiency. The Panasonic FV-08VQ model will move 90 cubic feet of air per minute with a power draw of only 17 watts and a very low sound rating of one sone (about the loudness of a modern quiet refrigerator). Running eight hours a day at eight cents per kilowatt hour, this fan costs less than $4 a year to operate. Fresh air to replace the exhausted air can be provided by installing a duct directly from the outside to the return plenum of your heating system. Thus the make-up air can be heated or cooled before it enters the supply duct. The fan should be wired to turn on in two ways: either by a manual wall switch, when the bathroom is being used, or by an automatic switch triggered when the furnace blower comes on. Heating or cooling the make-up air in this manner costs less than trying to manage air infiltration, plus giving the extremely important health benefit of exhausting stale air and providing fresh air.
An HVAC specialist may suggest variants on this system, depending on your particular home.
The bath fan system is reasonable in cost and effective for homes up to 1,800 square feet of living space. Larger homes may benefit more by installing a heat recovery ventilation system.
This system is best installed at construction but can be retrofitted. The good heat recovery ventilators are very quiet and recover 70 percent to 80 percent of the heat exhausted. They consist of supply and return ducts (separate from your heating system), a heat exchanger core and a fan. They cost several thousand dollars and should be designed and installed by professionals.
Although the initial cost is significant, consumer satisfaction with these units is high. Consult the Home Ventilating Institute (30 W. University Dr., Arlington Heights, Ill. 60004; (708) 394-0150 for details on the various models and their installation, and make sure that the heating contractor you choose is familiar with heat recovery systems.
LENGTH: Medium: 79 linesby CNB