Ducted UV systems for your HVAC exist now, and don't need to bother with the being UVC since the UV doesn't leave the system. If I recall correctly my furnace

Ducted UV systems for your HVAC exist now, and don't need to bother with the being UVC since the UV doesn't leave the system. If I recall correctly my furnace guy quoted me less than $2k for a whole house system that attaches to the air intake on my furnace.