ELECTRIFICATION AND DECARBONIZATION USING HEAT RECOVERY HEAT PUMP TECHNOLOGY FOR BUILDING SPACE AND WATER HEATING

Buildings are one of the major contributors to global greenhouse gas emissions. Decarbonizing building sectors has greatly been emphasized globally. For example, New York state has an aggressive roadmap to decarbonize the building sectors by 2050. To achieve this, electrification of space heating and water heating systems is critical, and it requires energy-efficient and feasible solutions rather than electric coil heating. This study proposes a heat recovery-enabled heat pump technology (i.e., variable refrigerant flow with heat recovery (VRF-HR)) for space heating and domestic water heating and presents a feasibility study of the proposed technology to evaluate decarbonization performance. A computational model is developed to simulate the energy performance of the proposed technology. The model uses a refrigerant circuit box to control refrigerant flows between indoor and heat recovery units for simultaneous space cooling, space heating, and/or hot water generation. A case study for apartment and hotel buildings located in New York City is conducted to demonstrate the feasibility of the proposed technology for decarbonization compared to a conventional system. Building energy simulations are carried out using a whole building energy modeling tool, EnergyPlus. Based on hourly simulation results, the post-process calculation is performed to examine the energy-saving and decarbonization potential by comparing with results from a conventional natural gas-based space and domestic water heating system. Results indicate that the proposed VRF-HR system can effectively achieve building electrification and decarbonization with lowered energy consumption (i.e., about 20% of annual cooling/heating energy savings and 80% of domestic hot water energy savings). Results also show that heat recovery technologies are a remarkable addition to enable electrification and decarbonization effectively.