Hermann Sperber

CALVIAS GmbH operates as a holding company, which engages in the acquisition, management, and sale of participations in companies that specialize in manufacture and sale of technical systems and equipment. It focuses on heating and ventilation systems, building technology, plant construction, electrical installation, as well as installation of material and electrical devices. The company was founded in 2016 and is headquartered in Trier, Germany.

Bolwin & Heemann Anlagenbau GmbH & Co. KG provides building technology solutions. The firm specializes in air conditioning, ventilation, refrigeration, measurement and control, heating, as well as plumbing technology. The company was founded on May 12, 2003 and is headquartered in Steinhagen, Germany.

Sperber GmbH engages in the provision of building services. It offers engineering; building automation; heating, ventilation and air conditioning (HVAC) systems installation; maintenance and repair; systems operation, facility management, and emergency services. The company was founded by Michael Sperber in 1947 and is headquartered in Trier, Germany.