Air quality issues abound in every indoor environment and it is becoming a concern in homes where a statistic from the EPA states that indoor air quality can be more polluted than outdoor air. There are a lot of issues and hype about the benefit or lack of benefit from UV light. The following is a brief tutorial on UV that I found helpful when doing research on the subject.
- The Centers of Disease Control (CDC) recommends the use of ultraviolet light. EPA has stated that indoor air can be as much as a 100 times more polluted than outdoor air. Bad air becomes “trapped” inside.
- The U.S.government now specifies that UV light should be used in air handling units to improve indoor air quality in government buildings, by controlling airborne and surface microbial growth.
- The Air Institute of Respiratory Education suggests UV lights be used in buildings for indoor air quality purposes, and states that may be the final line of defense against those diseases that have developed resistance to drugs, such as tuberculosis and others.
- According to the Aerobiological Engineering Dept. at Penn State University, the ultraviolet component of sunlight is the main reason microbes die in the outdoor air. The die-off rate in the outdoors varies from one pathogen to another, but can be anywhere from a few seconds to a few minutes for a 90-99% kill of viruses or contagious bacteria.
- The Centers of Disease Control (CDC) recommends UV lights in homeless shelters to prevent the spread of disease, particularly TB (tuberculosis).
- A study by Air & Waste Management Association found the combination of a HEPA air filter and germicidal UV lamp reduced bacteria by 80% in a 3072 cubic foot chamber.
The reduction of airborne microorganisms helps control the spread of colds and other illnesses that are transmitted through the air. The EPA says that indoor air is one of the top five environmental health risks of our time…while the Centers for Disease Control offer guidelines for using UV in hospitals to reduce the spread of tuberculosis… Ultraviolet light is well known to be germicidal (at certain frequencies). It is used widely to keep food and liquids germ-free during processing and packaging, and has been built into aircraft ventilation systems to help prevent infections.
UV air disinfection equipment “floods” areas of an HVAC system with UV light. As air circulates through the system, it is disinfected, resulting in a dramatic reduction of airborne bacteria and viruses.
Mold is one of the top five allergens… As an air conditioning system draws air, mold spores are drawn into the system, which accumulate and grow on the wet AC coil. UV works to keep mold from growing on the coil, which helps prevent mold and mold spores from being distributed by the system. The constant re-circulation of air through the HVAC system helps keep mold growth throughout the home or building in check.
UV saves money, too! Bio-contaminant build-up on an AC coil acts as an insulator. This causes the system to work harder to cool the air, wasting energy and increasing wear and tear on fans, compressors, motors and other components. Having UV in the duct system can reduce the build up of bio-contaminants on the AC coil.
