Paper No 585 – Performance evaluation of multi-functional cascade heat pump system for a residential building – 14th IEA Heat Pump Conference, Chicago, USA
With increasing fossil fuel usage in building air-conditioning systems, air-source heat-pump systems are in the spotlight as an alternative HVAC system to reduce carbon emissions. The aim of this study is to evaluate a multi-functional cascade heat pump system for a residential building. A design method suited in residential buildings was applied to evaluate system performance of the proposed system. A reference system as separate two heat pumps was selected in charge of cooling, heating and hot water supply. The target building was set to residential of 100m2, 5 occupants are in the building. The thermal load of the target building was derived with commercial transient simulation tool, thermodynamic equations, and model equations built-in EnergyPlus were used. As a result, the proposed system saves 13% energy in cooling mode and 10% in heating mode compared with the reference system. The energy saving effect was occurred at the compression ratio of each high- and low-cycle decreasing due to the effect of recovering unused waste heat in summer and increasing the temperature of the refrigerant in winter.