A heat pump water heater (HPWH) is an effective and efficient way to provide hot water for commercial buildings. The system uses a water heating heat pump to move heat from a cool reservoir such as air and transfer this heat into water. The system employs an evaporator, compressor, condenser, expansion valve, hot water circulating pump and controls to accomplish this function. Usually, an additional water storage tank is installed along with the HPWH so that the HPWH runtime is long and the system can meet much of the daily water heating load.Since the HPWH provides service water heating by moving heat rather than by generating the heat, the HPWH tends to be much more efficient than an electric Commercial Heat Pump Water Heaters Technology for Efficient Electric Service Water Heating resistance water storage tank.
I n the case of the HPWH, units with a coefficient of performance (COP) higher than 3.5 can be found. This means that for every kWh of electrical energy to the HPWH, more than 3 kWh of thermal energy is produced as hot water. One of the major benefits of the HPWH is the cooling that is generated as the HPWH operates to heat water. If the HPWH has an air-cooled evaporator that is located inside the building, then this cooling can be used to help cool the building interior during times when the HPWH is working to generate hot water. The HPWH is usually located to target "spot cooling" where it is needed. Generally, the economic attractiveness of the HPWH grows in cases where spot cooling can be utilized.