Water-to-water heat pump test facility

A novel facility for testing water-to-water heat pumps of residential size for heat recovery has been developed. It makes use of a mixing tank and a cooling tower and does not require any heating or other external cooling. Programmable PID controllers are used to maintain the temperatures of water supplied to the evaporator and condenser constant within a tolerance of ±0.2°C. The heating capacity can reach a steady state in less than 60 min for each set of water temperature settings. The facility has been used to test a heat pump, which makes use of a semi-hermatic compressor with a displacement volume of 26.8 m³ h^-1 and the test results are presented. By using the same principle, a similar test facility for heat pumps of larger capacities can be designed.