@libroraptor @isotopp @pezmico @dean
I get the impression that inside the HVAC ducts, UV is expensive and not super effective, bc air circulates through quicker than viruses get destroyed. You can add more UV lighting inside the ducts, but that gets even more expensive (and adds maintenance and safety issues -- UV shining out of grates, etc.). So high-quality mechanical filtration tends to be more effective. (But UV may be good for reassuring ppl.)