Spotlight on UVC in HVAC

By Robert Scheir, Ph.D., President, Steril-Aire, Burbank, Calif. April 6, 2005

Ultraviolet light C band (UVC) devices installed in the AC system are being used increasingly to eradicate surface and airborne mold, as well as viruses and bacteria. The devices eliminate the odors associated with mold, mildew and VOCs by cleaning the AC coils where they are installed.

On existing systems, the best results are obtained when UVC light is located downstream of and facing the cooling coil. It’s important to avoid installing devices in the return air ducts. Such installations will allow contaminated air to pass through the occupied space before UVC treatment occurs and does not address the greatest source, the cooling coil.

It is also important to select a UVC device engineered to deliver high output in HVAC conditions. It should be verified through independent testing to provide an output per inch of glass of not less than 10