AAON, Inc., together with its subsidiaries, engages in engineering, manufacturing, marketing, and selling air conditioning and heating equipment in the United States and Canada. It offers rooftop units, chillers, packaged outdoor mechanical rooms, air handling units, makeup air units, energy recovery units, condensing units, geothermal/water-source heat pumps, self-contained units, and coils. The company markets and sells its products to retail, manufacturing, educational, lodging, supermarket, medical, and other commercial industries. AAON, Inc. sells its products through a network of manufacturers' representatives and internal sales force. AAON, Inc. was founded in 1987 and is based in Tulsa, Oklahoma.