OR-05-07-3 - A Methodology to Evaluate Pumping Energy Consumption in GCHP Systems PDF

A methodology to evaluate the energy consumption of centralized and decentralized pumping systems in groundcoupled heat pump (GCHP) systems is presented. The analysis covers the first costs of the piping (interior and exterior) and of the circulating pump, as well as annual pumping energy costs. The methodology is applied to two buildings representing two distinct building/climate combinations. Results show that when the cost of the pumps and their installation are added to the life-cycle energy cost of 20 years of pumping, centralized systems for both buildings have total pumping costs that are lower than decentralized systems. It is also shown that the annual energy-weighted average wire-to-water pump efficiency of centralized systems is much better than for decentralized systems. Despite this pumping cost advantage, the overall costs (interior piping + exterior piping + pumpingrelated costs) of centralized systems are higher than for decentralized systems. This is primarily due to the high interior piping costs of centralized systems.

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