Beginning (1933–1966) In 1933
Mads Clausen (1905–1966) founded
Dansk Køleautomatik- og Apparatfabrik, later in 1946 the company name was changed to
Danfoss. The first product was an
expansion valve for refrigeration units, it was developed after studying imported valves from the US. In 1945 about 224 people were employed at the first factory built at and around the farm where he grew up. There was no more room for expansion and a new larger factory was planned. In 1962 the company started production of
power electronics, the first product was custom-built
rectifiers, later in 1968 production of the VLT
Frequency converter began, the first of its kind in the world. The company also expanded its activities into
hydraulics, the first hydraulic component was produced in the factory in
Nordborg in 1964. Mads Clausen died in 1966, at 60. Because his sons were too young to run the company, his widow Bitten Clausen took on the role as head of the board. The company had yearly sales of 500 million
Danish kroner, and the factory had grown to 10,000 m2.
Since 1966 Expansion into other countries started in 1956, when the company started to build a factory in
Flensburg,
Germany, which was completed in 1958.
Danfoss Compressors GmbH, Danfoss' former domestic compressor division, was sold in 2010 and renamed
Secop. China is also an important market for Danfoss. In 2013, two new factories were opened on the same day, bringing the number to seven. The Chinese market was the third largest for the company. In 2014, Danfoss purchased
Vacon, a
VFD manufacturer. In December 2025, it was announced that Danfoss, through its Power Solutions division, had completed the acquisition of Hydro Holding SpA, a manufacturer of hose fittings based in
Italy. The acquisition, which followed regulatory approval, resulted in Hydro Holding being integrated into Danfoss Power Solutions’ fluid conveyance division as a separate business unit. 2025,
BIEC ==Activities==