Today's homes are often built with energy efficiency in mind. They
are designed to "hold" air inside – thus avoiding heat loss during
cold winter months and and heat gain during the hot summer months.
Of course, what is better for your energy bills is not necessarily better
for indoor air quality; this type of "tight" construction often doesn't
allow these homes to breathe.
Weathertight homes tend to trap airborne particles inside, where everyday
household contaminants can become increasingly concentrated. The
result is that indoor air can become more polluted than the air outdoors.
Most people are not aware of the poor quality of some indoor air.
Many Americans spend up to 90% of their time indoors, either at home
or at their workplace, where they can be exposed to very high levels
of airborne particles. In fact, the EPA ranks indoor air pollution
among the top five environmental risks to public health.
Pollen, mold spores, pet dander, household dust, and tobacco smoke are
common indoor airborne particles. Most such particles cannot even
be seen; these contaminants are often associated with people's asthmatic
and allergic reactions. According to the EPA, levels of many
airborne pollutants may be 25 to 100 times higher than outdoors!
Indoor Air Quality Solutions
There are three basic methods for improving the quality of indoor air.
Source control.
The first approach – source control – is the most effective
method. This involves minimizing the use of products and materials
that cause indoor pollution, using good hygiene practices to minimize
biological contaminants (including humidity and moisture control, and
occasional cleaning and disinfection of wet or moist surfaces), and
following good housekeeping practices to control particle buildup.
Ventilation.
The second approach – outdoor air ventilation – is also
effective and commonly used. Ventilation methods include installing
exhaust fans close to contaminant sources, increasing outdoor air flows
in mechanical ventilation systems, and opening windows, especially when
pollutant sources are active.
Filtration.
The third approach – air cleaning – is not generally
sufficient in itself, but is often used to supplement source control
and ventilation. Air filters, electronic particle air cleaners,
and ionizers are often used to remove airborne particles when source
control and ventilation are inadequate. When the air is seriously
polluted, personal respirators may be used to directly filter the air
that people breathe into their lungs.
Indoor Air Quality Resources
Indoor Air Quality (IAQ)
provides basic information about indoor air quality issues in homes and residences.
Published by the United States Environmental Protection Agency.
American Lung Association - Healthy Air is a
comprehensive resource about many aspects of air quality,
including facts about indoor and outdoor air pollution. Learn about
potential dangers associated with poor indoor air and steps homeowners
can take to improve air quality in the home.
Indoor Air Quality Products
In addition to air cleaners, there are a number of other products and
appliances for the home that can help improve indoor air quality.
Central air conditioning systems can help keep you comfortable during
humid summer months. If central air is not feasible or affordable, a
room air conditioner
may be a more economical comfort solution. Both types of air
conditioning equipment generally clean the air to some extent.
For serious indoor air problems, you may wish to consider an efficient
HEPA filter.