By means of mixing valves, the heat streams can be controlled which are sent to certain systems, the mixing valves are opened and / or sealed by a servo motor according to a signal from the climate computer.
When using frequency-controlled circuitry systems, generally 3-way mixing valves are used. When using a pre-controlled luminaire, more frequent 4-way mixing valves are used because the flow remains constant.
Mixer valves are available in different versions, there are mixing valves that work with a plunger (Honeywell and Siemens) and mixing valves that work with a turntable (Centers and again Siemens). The plunger mixing valves generally have a better control characteristic and less leakage losses than the mixing valves with a turntable.