In a (closed) water source heat pump the cold loop of refrigerant is sent out into a heat exchanger set in the water flow. Because of the good conduction efficiency, the scale is relatively compact compared to the lengths of piping needed for ground source heating. Stainless steel heat exchangers were selected from the food industry for safety and longevity (but were relatively expensive) The heat exchangers are located in the inlet channel to the 'screw' protected from debris by the same inlet screen.
2 x 15KW Heat Pumps
2x 15KW Viessmann heat pumps were selected. These heat a buffer tank (on the left) upto 55C (depending on external temperatures). This then feeds the underfloor and old radiator heating system as well as preheating the hot water (boosted by an immersion heater)