Twin City Fan & Blower designs and manufactures industrial and commercial fans from its Minneapolis headquarters, with a dedicated smoke and heat exhaust fan range for emergency systems that remove smoke and heat from buildings during a fire. Those fans are built to withstand a minimum of 500°F for four hours or 1,000°F for fifteen minutes. The company operates its own AMCA-accredited test laboratory, holds AMCA Certified Ratings under AMCA 204, 210, 250, 260 and 300, and performs UL 705 safety testing in house. It trades under the Twin City Fan, Aerovent and Clarage brands.