Karl Völker

Part of Trius Holdings SCA, ista Deutschland GmbH is a company based in Essen, Germany that provides solutions to make buildings climate-friendly, safe, and comfortable. The German company's digital infrastructure can also be used for other applications, such as digital smoke alarm devices, which can be remotely serviced, increasing residents' safety. With over 6,000 employees in 22 countries, ista aims to become the partner for digitization and smart solutions for building owners and their residents. The company was founded in 1957 by Johannes Schultz, Karl Völker, and Thomas Zinnöcker has been the CEO of the company since 2016. ista offers data-based products and services that make individual energy consumption transparent to residents, helping them save energy, costs, and CO2 emissions.

Part of CK Hutchison Holdings Ltd., ista Energy Solutions Ltd. is a British company that provides energy services. The company is based in Duxford, UK. The company was founded in 1957 by Johannes Schultz, Karl Völker. The CEO is Thomas Zinnöcker.

ista International GmbH engages in the provision of energy management services. It also offers detect and protect solutions that include installation and maintenance of smoke alarm devices; and provision of leakage detection and tap maintenance and drinking water analysis services. The company was founded by Johannes Schultz and Karl Volker in 1957 and is headquartered in Essen, Germany.