General Info

Indoor Air Treatment With UV
UV’s effectiveness in killing bacteria is directly related to a microorganism’s exposure time. Indoor air in a typical residential forced-air HVAC
system will be recirculated over 50 times a day. With a UV generating lamp mounted in the HVAC duct, cumulative exposure can be very
effective in controlling indoor bacteria. UV rays will also kill germs that breed in drain pans and A/C coils. Properly positioned, an ultraviolet
system can significantly reduce indoor air contamination and prevent the growth of new microorganisms.
The treatment of indoor air with ultraviolet radiation has been successful in health care facilities, food processing plants, schools, laboratories
and other applications. It is a safe, silent, and proven method of improving indoor air quality.
Contaminant Kill Rate
The energy required to kill microorganisms is a product of the UV light’s intensity and exposure time. This energy is measured in micro-watt
seconds per square centimeter.
Intensity X Exposure Time = microWatt Seconds/cm
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The chart below illustrates the typical energy necessary to kill many common bacteria, viruses, yeasts & molds.
UV Energy Required for 99% Kill Rate
Bacillus anthracis 8,700
Corynebacterium diptheriae 6,500
Escherichia coli 7,000
Legionella pneumophila (Legionnaires Disease) 3,800
Leptospira interrogans (Infectious Jaundice) 6,000
Salmonella enteritidis 7,600
Salmonella typhosa (Thyphoid Fever) 6,000
Shigella dysenteriae (Dysentery) 4,200
Streptococcus hemolyticus 5,500
Vibrio cholerae (Cholera) 6,500
Bacteriophage (E. Coli) 6,600
Hepatitis virus 8,000
Influenza virus 6,600
Poliovirus 21,000
Rotavirus 21,000
Brewer’s Yeast 6,600
Baker’s Yeast 8,800
Aspergillus flavus 60,000
Mucor racemosus 17,000
Oospora lactis 6,000
Penicillium digitatum 44,000
Bacteria mW S/cm
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Virus mW S/cm
2
Yeasts mW S/cm
2
Mold mW S/cm
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FIGURE 1
Ultraviolet radiation by itself or in combination with a HEPA or other high quality filter, is the most effective way to reduce
airborne bacteria and the health risks they represent.
Warning: Never expose eyes or skin to UV-C light. UV lamps must only be operated inside metal ductwork where the light can
be contained.
• TH E FI E L D C O N T R O L S CO M P AN Y •
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