HVAC systems may need flu prevention treatment

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 global swine flu pandemic. In addition, the ever-present threat of mould 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 mould. High-output UV-C lights installed in the HVAC system are proving to be an effective and efficient strategy for mould, microbial and virus transmission control,” says Steril-Aire Inc. president and CEO Robert Scheir.

These devices rely on UV-C energy, the most germicidal wavelength in the ultraviolet spectrum. Installed in an air-handling system, high-output UV-C lights emit enough energy to penetrate even the tiniest microbe to destroy its DNA and RNA, thereby killing or deactivating it.

In a typical building with four to five air changes per hour, UV-C energy can destroy more than 90% 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, UV-C is even more effective, and can also reduce the incidence of nosocomial (hospital-acquired) infections.

Effective weapon

UV-C is an equally effective weapon against surface and airborne mould. Mould 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. UV-C lights keep coils, drain pans and other components free of mould and organic build-up, eliminating resultant allergic symptoms, as well as the time, cost and potential hazards associated with chemical cleaning programmes.

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UV-C 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 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, UV-C 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, UV-C also increases system efficiency, reducing energy, operating and maintenance costs.

HVAC energy savings of up to 15% to 20% are not uncommon. As a result, a UV-C installation can often pay for itself in just months, which is good news from a cost point of view.

UV-C kit for air handlers

Steril-Aire Inc. of the US has unveiled a new UV-C kit for air handlers, where it can destroy microorganisms such as flu viruses, bacteria and mould. The easy-to-install kit delivers ultraviolet-C technology to fan coil units, unit ventilator systems and indoor air handlers with coils up to 213,4 cm with dual access.

It delivers energy savings on retrofit installations, maintains factory design efficiency on new units and improves indoor air quality and infection control in all systems. Applications include air handlers serving patient rooms, classrooms, hotel/motel rooms, apartments and condominiums and offices in commercial buildings and industrial plants.

A slim power supply and convenient mounting options allow installation flexibility close to the face of the coil for continuous coil cleaning and optimum air quality. The high-output UV-C emitter has been tested independently to deliver up to six times the output of other ultraviolet devices under HVAC conditions.

It kills or inactivates airborne microbial contaminants to greatly reduce the spread of infectious diseases and eliminate the major source of allergy and asthma discomfort. It also eliminates surface biofilm to keep coils and drain pans in a constantly clean state, saving costs by reducing HVAC energy use and eliminating costly chemical cleanings.

The kit includes a universal 120-230V power supply and three mounting options for easy installation in different systems.

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