The FASS corp Process for Clearing the Air was invented for SARS in 2003. We have long understood that HEPA filters do not stop very small viruses. We have understood that UV light does destroy the virus, but it requires a longer contact time for the UV rays than you get by waving around a UV light in the air.

The Patented solution was to configure the HEPA filter in the shape of a W, and put the UV lights into the two V shaped notches. It required a special fiberglass UV filter, but when done, the special HEPA filter stops and holds the particles long enough for the UV lights to kill the viruses. The result was complete clearance of virus from the air.

Patent US 7,326,387B2: Air Decontamination Devices