OP, I don't think anyone knows the answer to that yet, but we do have a REME HALO system on our HVAC system and it DOES help with mold, allergies and bacteria and viruses circulating in your system. Here is the info, click on the Features and Benefits box and decide if this is something you might or might not be interested in. If you are looking for UV SURFACE cleaning, I would not consider this an option, only for your circulated air and to keep it out of your ducts as well (especially mold).
REME HALO(R) In-duct Air Purifier | RGF