This line of commercial kitchen makeup air systems is designed to provide tempered or untempered ventilation air to replace air exhausted through the kitchen hood. Model KSF supplies untempered makeup air. Model KSU supplies heated or cooled makeup air, with a direct-fired gas burner that provides a 100% efficient heating system, the company says. Model KSI, designed for outdoor installations only, features indirect-fired gas duct furnaces to provide tempered air. Airflow capacities range up to 12,000 cfm, heating capacities up to 1,375,000 Btuh. Greenheck, P.O. Box 410, Schofield, WI 54476-0410; 715-359-6171; 715-355-2399 (fax); www.greenheck.com (Web site).