New heat pump design claims efficiency gains

Described in Communications Engineering, the design couples a traditional air-source heat pump configuration with integrated heat storage in the form of a small water tank and a coil of copper tube. Excess thermal energy from the heat pump’s operation is captured and stored in the tank, which is used at a later stage to boost efficiency, as the stored heat is considerably warmer than the external air.

Made from off the shelf parts, the Glasgow team’s prototype delivered a 3.7 per cent efficiency gain compared with a traditional heat pump, at the relatively low heat supply temperature of 35°C. As supply temperature increases, so does the amount of energy recovered, improving the system’s efficiency.

According to the team’s analysis, an optimised system could be up to 10 per cent more efficient than current products at a heat supply temperature of 65°C. In addition, the recovered heat stored in the water also allows the flexible heat pump to run continuously during defrosting, something most current models cannot do.