Admixing circuit

Compared to the diverter circuit, the admixing circuit has a secondary circuit pump. The 3-way control valve is also located in the flow pipe.

In a heating system with several secondary circuits, the primary circuit must contain a main pump.

The secondary circuits each have their own pump. In this case, an open distributor must be provided which acts as a zero point between the primary and secondary circuits. The secondary circuit pumps always deliver a constant flow of water. The actual output control is performed by the 3-way control valve, which raises the temperature in the secondary circuit flow by closing the bypass.

The design of the secondary circuit pump only takes into account the pressure difference of the heat exchanger, which is particularly advantageous for unknown primary networks.

For temperature control in centralised ventilation units, the admixing circuit is often found in heaters, but is also suitable for coolers without dehumidification.

Control scheme admixing circuit