My sister-in-law has a gas, forced air, central HVAC system with an Aprilaire humidifier attached. She said that a plumber who was there fixing a kitchen faucet leak saw her HVAC system and suggested that she should get a UV light put in. He told her that without one, mold develops, and with one she could prevent mold and even help prevent spreading things like the H1N1 flu virus.
She asked me if I knew anything about that -- using UV lights in an HVAC system -- which I don't. I asked her if the guy said how much something like that might cost and he said around $1,000.
Is the use of UV lights in HVAC's for real and something that homeowner's should have installed?
And, if so, can anyone give me a general idea of what something like that might typically cost for an HVAC person to install?