1910: Establishment of a handicraft business by master coppersmith Emil Künzel in Guben (Niederlausitz, Germany). Pipes and production of individual items.
End of the 20s: World financial crisis. Business taken over by engineer Paul Künzel.
1935: Heating stove for solid fuels with patented lift/lower grill goes to production.
WWII, escape from Guben.
1950: Reestablishment of the business (PA-KÜ-Werk) in Pinneberg.
1955: Cooperation with Ruhrkohle AG.
1962: 10,000 heating stoves purchased in one year.
1964: Oil-fired heating stoves, steel boilers.
1974: Heating chest becomes most important product.
1975: Transfer of the company to engineers Manfred Künzel (business management) and Haiko Künzel (technical management).
1978/79: Oil crisis. Focus on firing techniques for solid fuels. Internal combustion system for agricultural operation, trade and commerce.
1985: Wood gasification boiler with patented centrifugal chamber burner.
1989: Microprocessor controller for wood gasification boiler.
1991: Biturbo wood gasifier boiler with two blowers, automatic ignition and lambda sensor for particularly exact combustion regulation.