The DRI Treated Fresh Air Units provide a complete solution for IEQ and Energy Saving in a single modular unit with option to add modules for cooling, heating, humidification, high efficiency filtration, mixing, sound attenuation, etc. Treated Fresh Air Units (TFA) are also sometimes referred to in the industry as Fresh Air Handing Untis FAHU, Fresh Air Units, Rooftop Units, Outdoor Air Handing Units OAHU, Energy Recovery Units or simply Air Handling Units.