As construction methodologies have improved, more and
more homes are becoming increasingly airtight in order
to reduce air leakage, improve energy efficiency, reduce
heating and cooling costs, further occupant comfort and
strengthen structural durability. However, without fresh
outdoor air replacing stale indoor air, an unintended
consequence is deficient indoor air quality (IAQ).
Indoor spaces are full of air contaminants. The EPA
found that indoor air may be 2-5 times,
and occasionally greater than 100 times,
more polluted than outdoor air. Indoor air
contaminants are derived from a variety
of sources, and can cause health
problems and reducedcognitive function.