SF-98-05-1 -- Well-Pumping Issues in Commercial Groundwater Heat Pump Systems PDF

Groundwater flow minimizes total system power (well pump, heat pumps, loop pump) and is based upon building peak block load. Optimum flow for water temperatures in the 50°F to 70°F range is 1.25 gpm to 2.5 gpm per ton of peak block load, depending upon total pump head. Submersible pumps are likely to be the type used in most systems. Contrary to popular belief, well pumping does not result in substantially lower groundwater system performance (system EER, system COP) compared to closed-loop systems. In fact, groundwater systems, due to more favorable operating temperatures, can offer performance superior to ground-coupled systems under certain circumstances. All systems evaluated in this report employ a plate heat exchanger to isolate the heat pump from the groundwater.

Units: I-P