What You'll Learn
Ventilating the Area Your mom was right. Fresh air is good for you. Ventilation removes indoor air and adds outside air to dilute the overall level of allergens. Exhaust fans in the kitchen and bathrooms will help remove odors and moisture, but they must be vented to the outdoors to work properly. A clothes dryer, attic and crawl space should also be vented outdoors. HVAC help. Very tightly constructed homes—those with wall and ceiling insulation, continuous vapor barriers and weather-stripped insulated windows and doors—might need a whole-house ventilator. These can often be added to a forced-air heating system; leave this job to a heating and cooling contractor. Before you start using any heating or cooling appliances, have them inspected and cleaned by a professional. The service call should include cleaning coils, drain pans, fans and heat exchangers; adjusting heating products to meet operating specifications; inspecting any venting system and combustion air supply; and checking that fresh-air intakes are separated from appliance vents to prevent recirculation of combustion gases. If, as part of your forced-air system, return vents are located in hallways, be sure to keep doors open to rooms without return vents. Otherwise air pressure and humidity differences between rooms could increase the concentration of allergens. Lowering humidity. Dust allergens and mold and mildew thrive on humidity. While relative-humidity levels between 30 and 50 percent are generally recommended for most households, a level of 35 to 45 percent may be more comfortable for allergy or asthma sufferers. Michael Lamb, energy specialist with the U.S. Department of Energy Conservation and Renewable Energy Inquiry and Referral Service, says homeowners can pick up a relative-humidity gauge that's accurate within a few percent at electronic and hardware stores for $10 to $20. You can control room humidity with a humidifier or dehumidifier. However, says Dr. Cugell, "Room humidifiers are easily contaminated by mold and bacterial growth and are a known source of considerable respiratory problems." So check it frequently for mold and mildew, add fresh water every day to a room humidifier and clean it every three days. You should also check a dehumidifier on a regular basis.