AAON Inc. is a manufacturer of heating, ventilation, and air conditioning (HVAC) equipment for commercial, industrial, and data center environments. Operating primarily in the United States and Canada, the company specializes in highly configurable, semi-custom HVAC systems designed for energy efficiency and performance. AAON is distinctive for its mass semi-customization approach, which combines the cost efficiency of scaled production with the precision of individual customization.
For the years ended December 31, 2025, 2024, and 2023, AAON had three, two and three customers, respectively, that individually represented 10 percent or greater concentrations of revenue; the company notes it has supported these significant customers with long-standing multi-year programs. The remaining majority of its business comes from thousands of customers and transactions through an extensive network of independent manufacturers' representatives (including firms such as Texas AirSystems and related portfolio groups Meriton, Ambient and Air Control Concepts), which the company says mitigates its concentration risk. Sales are overwhelmingly domestic: foreign sales were approximately $38.1 million (2.6% of net sales) in 2025.