Indoor air quality is at the forefront of research in the health and building communities. Experts concur that certain airborne contaminants cause widespread discomfort and health problems, leading to absenteeism from school and work as well as reduced productivity. Healthy and productive indoor environments would save billions of dollars in health care costs, lost work time, overall output and possible litigation.

HVAC systems play a major role in the indoor air quality of buildings. Therefore it is logical to target this system with products that mitigate or eliminate IEQ problems. In all types of HVAC equipment, mold can proliferate year-round. HVAC systems are the perfect source and conduit for the origin and/or spread of microorganisms. Their environments are especially conducive to amplifying molds and some bacteria. Running contaminated system air-handlers disseminates and/or recirculates system, space and occupant-generated microorganisms room-to-room and person-to-person.

Contamination of the evaporator coil occurs in part as the role of the filtration system is compromised: (1) because growth occurs downstream of filters, allowing microorganisms to seed the ductwork and travel to and throughout the occupied space; and (2) because viruses and many bacteria are too small to be captured by the average air filter.

With most individuals, prolonged exposure to mold and mold products initiates the release of histamines, causing inflammation of mucous membranes, which can be followed by congestion, breathing difficulties, asthma and other complications.

According to the World Health Organization (WHO), the combined effects of bioaerosols in indoor air accounts for a substantial portion of the absences from school and work, as well as days where activity is impaired or restricted. They also report that the cost of these losses far exceeds the cost of owning, operating and maintaining HVAC systems.

Because IAQ professionals agree that bioaerosol controls other than UVC tend to be impractical, toxic, detrimental to equipment operation, or simply too costly, there is growing interest in UVC as the most practical and effective source control available.