Facility owners and managers are well aware of the lost productivity, ill health effects, and even litigation that may arise when infectious disease spreads through a building. This year, in addition to the usual seasonal colds and flus, there is widespread concern about a bird flu pandemic. In addition, the ever-present threat of mold contamination can trigger allergy and asthma symptoms among building occupants, leading to further health issues.
To prevent these problems, you must treat the HVAC system, which functions both as a conduit for airborne microbial contaminants and a breeding ground for mold. High-output UVC lights installed in the HVAC system are proving to be an effective and efficient strategy for mold, microbial, and virus transmission control.
These devices rely on UVC energy, the most germicidal wavelength in the ultraviolet spectrum. Installed in an air-handling system, high-output UVC lights emit enough energy to penetrate even the tiniest microbe to destroy its DNA and RNA, killing or deactivating it.
In a typical building with 4 to 5 air changes per hour, UVC energy can destroy more than 90 percent of infectious microbes with each air change - reducing them to a level far below what it takes to infect most people. It works against all strains of influenza (including bird or Avian flu); other viruses (including colds, SARS, measles, and German measles); and bacteria (including TB, Legionella, pneumonia, and whooping cough). Most hospitals use 15 to 20 air changes per hour; in these environments, UVC is even more effective and can also reduce the incidence of nosocomial (hospital-acquired) infections.
UVC is an equally effective weapon against surface and airborne mold. Mold originates deep inside the HVAC system, where the cool, moist conditions provide an ideal environment for its growth. It rapidly builds up on coils and releases spores and other contaminants that travel through the air stream and into the occupied space. UVC lights keep coils, drain pans, and other components free of mold and organic build-up, eliminating resultant allergic symptoms as well as the time, cost, and potential hazards associated with chemical cleaning programs.
UVC technology is adaptable to virtually any type of HVAC system - including those with limited space and/or access. This includes offices, patient rooms, classrooms, and similar areas served by unit ventilators, fan coils, and other room unit air-handlers. These packaged systems present a special IAQ challenge because most have tight space constraints and can only be equipped with low-efficiency filters that do not effectively capture harmful contaminants. From the smallest packaged room unit to the largest central air-handling system, UVC protection can be added without costly modifications to the air-handler itself. The germicidal effect is virtually immediate and continuous, as long as the lights are kept on 24 hours a day with the fan running.
By keeping HVAC components clean, UVC also increases system efficiency, reducing energy, operating, and maintenance costs. HVAC energy savings of up to 15 to 20 percent are not uncommon. As a result, a UVC installation can often pay for itself in just months. This is good news for those who want the protection - but not the worry about the added cost.
Robert Scheir is president and CEO at Burbank, CA-based Steril-Aire Inc. (www.steril-aire.com).