EHR-ZKO controller for heat exchangers

The autonomous controller EHR-ZKO is an additional device designed for air handling units with the option of air intake directly from the outside or via a ground heat exchanger:

- The ground heat exchanger is used by the controller in the cold season of the year when the outside temperature drops below the set limit - the intake air is heated by the heat of the ground heat exchanger. Similarly, in the warm season of the year, the ground heat exchanger is used when the temperature exceeds the set temperature limit - the intake air gives up its heat to the ground heat exchanger.

- For the ground air exchanger, the change of the intake (directly from outside or from the ground collector) takes place continuously within a certain adjustable range of outdoor temperature. For a ground liquid heat exchanger, the pump of the ground heat exchanger circuit is switched from certain limits of outdoor temperature.

The controller is mounted on the wall in the indoor space, the temperature sensor is placed on the north façade protected from direct weather. The controller shall be interfaced with either the actuator for controlling the damper of the ground air exchanger or the pump of the ground liquid exchanger.

The temperature for winter and summer operation and the steepness of the control (switching hysteresis) can be set on the controller.

The controller also includes an outdoor temperature sensor. Dimensions: 230 × 275 × 140 mm.