Air purification devices are commonly employed in home, office and industrial settings as a way to remove harmful components from the ambient air and to improve air quality. Potentially harmful components that can be found in the air include chemical pollutants, odors, airborne particles, bacteria and/or the like. Air purification devices can be employed for many uses including treating the exhaust gases from motor vehicles and other processes, for the generation of sterile environments and “clean” manufacturing facilities, and for removing pollutants that are commonly found in home, office and industrial environments.
Volatile organic compounds (VOCs) are gaseous phase organic compounds that are present in the environment from a variety of sources. VOCs are can be outgassed by common manufactured items found in home and office settings such as carpets, paint, cleaners, furniture, and plastics as well as sources such as cigarette smoke or exhaust from passing automobiles. VOCs are also produced across a range of industrial processes including refineries, semi-conductor manufacturing plants, and chemical manufacturing including paints, coatings, pharmaceuticals.
The levels of pollutants such as VOCs can be 2-5 times higher indoors compared to outdoor levels. Mechanical ventilation systems can help decrease the levels of indoor pollutants depending upon the levels of pollutants found in the outside environment. A mechanical ventilation system can turnover an indoor air volume as the rate of 1 to 3 hr−1, while the turnover rate can be as low as 0.1 to 0.4 hr−1 without mechanical ventilation. The largest reduction of airborne pollutants including VOCs can be achieved by directly treating air to remove pollutants or to convert pollutants to harmless byproducts.