The Fresh-Aire UV APCO is installed in the ductwork of your central air system and is designed to help reduce airborne odors, toxic chemical vapors, germs and mold in your home.The combination of germicidal UV light and activated carbon cells inside APCO make it uniquely effective at reducing volatile organic compounds in the air without producing any harmful ozone. VOCs cause odors and include toxic chemical vapors like formaldehyde and toluene.The APCO RT has the same technology as the original APCO but designed for smaller ducts. APCO RT features a 9' Fresh-Aire UV lamp and 4 activated carbon cells. Available with low-voltage 18-32 VAC or line-voltage 120-277 power supply.TUV-APCO-RT-ER In Duct air purifier includes a TUVP-ER 18-32 VAC power supply, TUVL-2RT 2 year UVC lamp, and advanced PCO cell