Your HVAC system circulates air through every room in your home, including the air handler and ductwork. A professionally installed HVAC UV Light System places a UV-C lamp (commonly 254 nm) inside the air handler or ductwork, usually aimed at the evaporator coil or the airstream.
This is a hard-mounted lamp, not a portable purifier. What it does depends on lamp type, placement, airflow and maintenance. It is an HVAC accessory, not a medical device, and Home+ does not promise a specific germ-removal percentage or health outcome.