Theoretical comparisons between absorption heat pump and electrical heat pump for low temperature heating.

Energy consumption for heating and DHW is very high, and heat pump technologies are becoming popular. Air source absorption heat pump (ASAHP) and air source electrical heat pump (ASEHP), ground source absorption heat pump (GSAHP) and ground source electrical heat pump (GSEHP) are theoretically compared. Comparisons between ASAHP and ASEHP indicated that: (1) ASAHP is advantageous over ASEHP under colder conditions; (2) exergy efficiency of ASAHP is higher than that of ASEHP in most conditions; (3) high-efficiency ASAHP is always more emission-reduction than ASEHP, while low efficiency ASAHP is more emission-reduction than ASEHP when ambient is below 0°C. Comparisons between GSAHP and GSEHP revealed that: (1) annual primary energy efficiency of high-efficiency GSAHP is higher than that of GSEHP, while low-efficiency GSAHP is worse than GSEHP; (2) GSAHP is more suitable for colder regions with reduced thermal imbalance; (3) borehole number of GSEHP can be reduced by 40~50% using GSAHP.