AAON, Inc., together with its subsidiaries, engages in engineering, manufacturing, and selling air conditioning and heating equipment primarily in the United States and Canada. It offers rooftop units, chillers, air-handling units, make-up air units, heat recovery units, condensing units, commercial self contained units, and coils. The company markets and sells its products to retail, manufacturing, educational, medical, and other commercial industries. AAON, Inc. sells its products through manufacturers' representatives and internal sales force. The company was founded in 1987 and is based in Tulsa, Oklahoma.