Air purification frequently includes the mitigation of airborne microbials. The need for
such purification is self-evident in many situations. For example, hospital acquired
infections (HAIs), some that are attributable to pathogen in the air, kill more people in
the United States than AIDS, breast cancer, and auto accidents combined.
Ultraviolet light, referred to as Ultraviolet Germicidal Irradiation (UVGI) is one of the weapons used in
the arsenal of solutions to combat disease transmission via the air. In use to disinfect air since the
1930s, it remains a proven method for improving the air quality in HVAC systems.
UV-CThe electromagnetic wavelength emitted by UV-C lamps is approximately 254 nm. This is a near perfect match to the 265 nm wavelength that is most effective in deactivating pathogens, and therefore these germicidal UV emitters are frequently used in healthcare, food processing, or other applications where control of disease is paramount.For use with HVAC systems the germicidal benefit of UVGI can be realized in a number of ways. Perhaps the most common is “coil maintenance”, which refers to treating the wet side of a cooling coil and the drain pan to prevent the formation of mold in the damp, dark section of an air handler. It also helps keep the coil pressure drop from rising due to contamination. Similarly, UV lamps placed upstream of a final filter will expose the pathogens captured in the filter for an extended period of time for very effective deactivation. This helps prevent any “spill” of microbials when the filters are replaced. UV-C can also be used for moving airstreams, although the effectiveness is not as pronounced since the virus, bacteria, or allergen does not remain exposed to the light for more than a short period of time. Bioclimatic can help you determine the best use, placement of components, and density of UV to maximize the performance. Bioclimatic provides the controls and protections to assure safe and effective operation of its UV systems. In all cases the lamps are selected to prevent the release of shorter wavelength radiation that can result in ozone generation, an important consideration in the application of any air cleaning device.Benefits•Better IAQ for reduction of disease transmission, reduced absenteeism, better productivity•Prevention of fungal contamination in air systems, reducing maintenance costs•Control of odors from biofilms•Defense against bioterrorism in safe rooms•UVGI is the only air treatment truly lethal to microbials