Desiccant Rotors International Pvt. Ltd. Manufactures Treated Fresh Air Units. Desiccant Rotors International Pvt. Ltd. Offers various equipments for energy recovery and ventilation/fresh air treatment. The Treated Fresh Air Units are energy saving systems in a single modular unit with option to add modules for cooling, heating, humidification, high efficiency filtration, mixing, sound attenuation, etc.