System schematic of an open and sealed system with a heat pump and a solid fuel stove, two underfloor heating zones and domestic hot water (DHW) cylinder. The heat pump and underfloor heating zones are a part of a sealed system while the solid fuel stove is a part of an open system.
To connect the two different system types an NRG Link is used. The NRG Link ensures that the solid fuel stove has an open system as required for safety reasons, while still being able to transfer its heat to the sealed system. The DHW cylinder is on the gravity fed circuit of the solid fuel stove and acts as the heat leak of the stove. Since the cylinder has two coils it can also be heated by the sealed system when the solid fuel stove is not burning.
The NRG Zone 4 manifold ensures that the heat pump receives the coldest possible return water so that it is working under optimum conditions and with optimal efficiency. The manifold also ensures that the underfloor heating zones have access to the warmest possible water for their flow. The manifold also provides the system with a full bypass, meaning that the heat pump can always maintain its optimal flowrate.