ASHRAE - American Society of Heating@ Refrigerating and Air-Conditioning Engineers@ Inc.
适用范围
This paper discusses a technical comparison of a directexpansion ground-source heat pump (DX-GSHP) and an airsourceheatpump( ASHP).Tolowerthegroundheatexchanger size for cost reduction purposes@ the system performance of a hybrid system is also evaluated using a supplementary air evaporator combined with the DX-GSHP. Detailed screening models previously developed for ASHPs and DX-GHSPs are first used to compare the seasonal performance of these two options for a residential building in the cold-climate city of Montr??al@ Canada. Then@ the model is adopted for performance evaluation of the hybrid system. Additionally@ different parameters including borehole total length and heat pump capacity are varied to evaluate their impact on the seasonal system performance. The results show that by adequate sizing@ total and peak electricity consumption of theDX-GSHPsystem can be reduced by 50% and 40%@ respectively@ compared to an undersizedDX-GSHPsystem.However@systemenergysavings from using a hybrid ground-source heat pump (HGSHP) are marginal compared to a DX-GSHP (5.5% for a low-capacity system)@ and these savings are happening during the shoulder months. Such results highlight the importance of further investigations in the area of DX-GSHPs to reduce the borehole installation cost and increase its performance.