Danfoss Compressors GmbH was a subsidiary of the Danfoss Group, a Danish manufacturer of valves and fluid-handling products, from 1956 to 2010. It produced hermetic compressors for household appliances and mobile cooling. In 2010, the Danfoss Group sold Danfoss Compressors GmbH to the Munich-based industrial holding company Aurelius AG and established a new brand under the name Secop GmbH. In 1933, Mads Clausen, an engineer specializing in air conditioning and refrigeration, established the Danish Cooling Automatic and Appliance Factory in his boyhood attic room in Elsmark, on the Danish island of Als. He started producing automatic valves for refrigeration plants, which previously had to be imported from the United States.