Air source assisted ground source composite heat pump system: life cycle carbon emissions and simulation analysis

Air source assisted ground source composite heat pump (DSHP) system is a combination of ground source heat pump (GSHP) and air source heat pump (ASHP) that makes use of both underground and outdoor temperatures to ensure long-term stability and reliability. The development of a carbon emission model for DSHP system involved a life-cycle assessment (LCA). This model was used to analyze the energy savings of DSHP in two different areas of China Nanjing and Hohhot. In both cases, an office building with an area of 3040 m2 was used as the subject of the study. The evaluation of energy savings using TRNSYS dynamic simulations revealed that the operation stage accounts for about 75%-85% of the carbon emission in the entire life cycle assessment of DSHP systems, Among them, refrigerant leakage produces a carbon footprint of more than 20%. The installation stage accounts for about 10% of the emissions, while the adjustment of the power energy structure during operation is crucial in achieving energy savings and emission reductions. A comparison study shows that DSHP can lower emissions by up to 23% when compared to traditional air conditioning systems like gas boiler and chiller system (BLR-CH). The use of DSHP is therefore a highly effective alternative for organizations committed to reducing their carbon footprint.