Comprehensive investigations of life cycle climate performance of packaged air source heat pumps for residential application

In this paper, the comprehensive life cycle climate performance (LCCP) assessments are detailed from various influencing parameters for the packaged air source heat pumps. The seasonal energy efficiency ratio (SEER) rating for heat pump systems has a far greater impact on lowering carbon dioxide equivalent (CO2-eq.) emissions. 13 SEER R410A has a 1-7% CO2-eq. emission reduction as compared with the 13 SEER R22, and 14 SEER R410A depicts a 7-19% reduction. In general, for all three categories, from cold areas (such as Minneapolis) to hot areas (such as Phoenix), the cooling demand is increasing and heating demand is decreasing. There are no back up heat in hot areas, especially in San Antonio and Phoenix. Due to the comfortable weather itself, balmy area such as Los Angeles, has the lowest emissions. Among the emission contributors, the energy consumption accounts for appropriately 90% of the total emissions. When the COP is improved by 5%, 10% and 15% as compared with the baseline 14 SEER R410A, the corresponding LCCP is decreased by 4%, 8%, and 12%, respectively. Therefore, to achieve the efficient CO2-eq. emission reductions, more attentions should be paid for energy efficiency improvements. The refrigerant recovery rate has the negligible effects on the LCCP results. The cycle degradation coefficient has the slightly larger influence than the refrigerant recovery rate on the CO2-eq. emission reductions. In addition, due to the better load matching (few cycles and less temperature and humidity swing), the 14 SEER two capacity heat pump product has appropriately a 5% CO2-eq. emission reduction as compared with the current single speed 14 SEER R410A heat pump.