Heat pump controls

Greenstore heat pumps are controlled by the Rego 637 control unit.

The unit ensures that the heat pump runs efficiently when required and dictates that hot water heating is given priority over space heating.

Diagram of controls

Outdoor sensor

The heat pump is controlled with an outdoor sensor which determines the temperature outside of the property and relays this back to the heat pump. The control on the heat pump uses a heat curve to provide a corresponding flow temperature from the appliance, always endeavouring to provide the lowest flow temperature possible yet still maintain desired room temperatures.

Room sensor

In addition to the outdoor sensor, a room sensor supplements the control of the heat pump. This allows the controller to compare the internal and external temperatures, providing the best possible energy savings.

Heat curves

The return temperature to the heat pump is determined directly by the outdoor temperature sensor according to a heat curve. The heat curve can be changed to provide different responses from the heat pump to the outside temperature.

Curve slope:

2 - 4 Normal setting for floor heating

4 - 6.5 Normal setting for radiators

7 - 10 Abnormal high setting (not normally required)

Heat curve slope 4 gives a return temperature of +35ºC when it is 0ºC outdoors. If the outdoor temperature drops the return temperature increases. The colder the outdoor temperature the higher the return temperature. At an outdoor temperature of approximately -30ºC the curve slope has nearly reached the limit value (+57ºC) for the return temperature.

Fine-tuning the heat curve