Indoor air quality (IAQ) is a term which refers to the air quality within and around buildings and structures, especially as it relates to the health and comfort of building occupants. In the last several years, a growing body of scientific evidence has indicated that the air within homes and other buildings can be more seriously polluted than the outdoor air.

HVAC (heating, ventilation, air conditioning) systems process air from inside the building by drawing it through a return air duct, carrying it through the ductwork to the heating or cooling unit, conditioning it, and then sending it back through the supply air ducts to the interior of the building.

The air your breath inside your home or place of business is being re-circulated through the ductwork night and day, each time the heating or air conditioning systems are on.

If not properly maintained, this same ductwork can become a breeding ground for mould, bacteria or fungi waiting to be released back into the living quarters of any building as the reconditioned air circulates.

IAQ can be affected by gases including:

carbon monoxideradonvolatile organic compounds VOC’s, particulatesmicrobial contaminants such as  mouldbacteria or any mass or energy stressors that can induce adverse health conditions. Source control, filtration and the use of ventilation to dilute contaminants are the primary methods for improving indoor air quality in most buildings.

Determination of IAQ involves the collection of air samples, monitoring human exposure to pollutants, collection of samples on building surfaces and computer modelling of air flow inside buildings.

Source: Wikipedia, the free encyclopedia