The government says that the primary causes of indoor air-quality problems are sources of pollution that release gas or particles into the air. Outdoor air must be brought into a house to dilute emissions and carry these pollutants outside, where they can dissipate. High temperatures and high levels of humidity also can increase the levels of pollutants.

Sources of indoor pollution include combustion sources such as oil, gas, kerosene, coal, wood, and tobacco. Since the 1950s, residential builders have used more manufactured products in construction and remodeling. Plywood, adhesives, and a host of home furnishings such as carpets and drapes are manufactured with thousands of chemicals.

Air from the outdoors needed to dilute indoor pollution can enter a house three ways: infiltration (through cracks in the walls and joints in floors), natural ventilation (open doors and windows), and mechan ical ventilation (outdoor-vented fans such as those in range hoods in kitchens and in bathrooms, as well as whole-house systems that remove indoor air and distribute filtered air through the house).

So, can central air-conditioning solve your moisture and ventilation problems? Most central air-conditioning systems are not sized properly for the house, and they do not run all the time, kicking in when they are needed. A better answer is to have a dehumidifier running from June to November. Be sure to clean the filter regularly and get rid of the water. Poorly maintained dehumidifiers can work against you.

Tagged: air, breath, caution, health, homeowner, house, pollution, ventilation