Carlson & Stewart Refrigeration, founded in 1938 as Carlson Sales & Service, is a design-build contractor specializing in commercial and industrial refrigeration systems. The company offers system design, equipment sales, complete installation, and service to its industrial and commercial customers in Minnesota, North Dakota, South Dakota, Nebraska, Iowa, and Wisconsin. The company s trained technicians have more than 15 years experience with a wide range of systems, from small self-contained units and rack systems for commercial customers to large ammonia systems for industrial customers. The firm is a member of the International Institute of Ammonia Refrigeration, American Society of Heating, Refrigerating and Air Conditioning Engineers, Refrigerating Engineers and Technicians Association, and Refrigeration Service Engineers Society. Carlson & Stewart Refrigeration has offices in Marshall, Minn, and Sioux Falls, S.D.