I just had the condenser coil replaced in my home AC. On the way out the repairman mentioned the Reme Halo (air purification) and UV light (to prevent mold from growing on the coil). Does anyone out there have real world experience with either? They aren't cheap and are installed directly into your duct system. He quoted my $799 for the Reme Halo and $499 for the UV light (includes installation). Is this a money making gimmick for the HVAC folks or is it for real? Anyone out there with real world experience with either of these? And is this guy's estimate in line with what others are charging?