AAON, Inc., together with its subsidiaries, engages in the manufacture and sale of air-conditioning and heating equipment primarily in the United States and Canada. Its products include standardized and custom rooftop units; chillers; make-up air units; heat recovery units; air-handling units that consist of coils, blowers, and filters; condensing units comprising coils, fans, and compressors; coils consisting of a sheet metal casing with tubing and fins; and boilers that include boilers and a sheet metal cabinet. The company's products serve the commercial and industrial new construction and replacement markets. AAON sells its products primarily to property owners and contractors through a network of manufacturers' representatives and its internal sales force. The company was founded in 1987 and is based in Tulsa, Oklahoma.