AAON has been serving the heating, ventilating and air conditioning industry since its inception. The products offered by the company include rooftop, condensing units, air handlers, chillers, coils, and air wise. It offers packaged air-cooled and evaporative-cooled chillers. The products also include customer specification coils and booster coils. AAON is affiliated with various organizations, including American Society of Heating, Refrigerating, and Air-Conditioning Engineers, Air Conditioning and Refrigeration Institute, Air Conditioning Contractors of America, Geothermal Heat Pump Consortium, and Environmental Protection Agency. It is certified by International Organization for Standardization and American National Standards Institute. AAON has operations in Tulsa, Okla., Longview, Texas, and Ontario, Canada.