High-volume, low-speed (HVLS) fans are industrial-grade fans that are designed to circulate large volumes of air at relatively low speeds. They are typically used in large indoor spaces, such as warehouses, manufacturing facilities, and gymnasiums, to improve air circulation and reduce energy costs. HVLS fans typically have diameters of 7 to 24 feet and can move up to 20,000 cubic feet of air per minute. They are often used in conjunction with other HVAC systems, such as air conditioning, to improve overall air quality and comfort.