Heating water for potable use is the second largest demand for #energy in any structure with bedrooms and bathrooms. Most water heating systems in use today operate at 65%-85% efficiency. #heatpumpwaterheaters provide the same service while using ~25% of the energy (250%-300% efficiency) compared to any other method. A #HPWH system always includes hot water storage. In multifamily buildings, the hot water storage tanks are quite large; 800 gallons (3,028 liters) pairs with a 250,000btu/hr (73kW) HPWH. For Time of Use rate structures or #Demandresponse the HPWH can preheat using renewable energy during times of low grid demand, and remain off through the grid peaks. This combination of #efficiency and shiftable load provides massive #carbon emissions reductions and operational cost benefits to the occupants and the building owner.
This is a Piping and Instrumentation Diagram of a HPWH system.
