Carsten Stelzer

Turk Demir Dokum Fabrikalari AS manufactures and markets heating and cooling systems. It offers heating and cooling apparatus ranging from panel radiators, water heaters, central heating system, individual heating system and air conditioners. It operates through a brand of Heat Comfort. The company was founded by Vehbi Koc on September 29, 1954 and is headquartered in Istanbul, Turkey.

Vaillant GmbH engages in the manufacture and distribution of heating ventilation and air-conditioning products. The firm offers solar-thermal and photovoltaic systems, heat pumps, and pellet boilers. It also provides gas-fired condensing boilers, ventilation systems for low-energy buildings, combined heat and power stations, high-efficiency heating systems using fossil fuels, intelligent controls, air conditioners, and radiators. The company was founded by Johann Vaillant in 1874 and is headquartered in Remscheid, Germany.