The objective of ASHRAE research project 1217-TRP was to develop accurate performance models of ground-coupled heat pump (GCHP) pump and piping system designs and to provide easy-to-use evaluation tools. One product of this project is a GCHP bin method program that integrates the measured results for pump energy and demand for several design options with annual heat pump energy use. The basics of the program are described in this paper. Analyses for an example office building are presented for systems that follow ASHRAE energy-efficient recommendations and systems that are oversized. Multiple subcentral piping systems with unitary circulators and central systems with variable-speed pump motors consume the least amount of energy, while constant-volume pumping and primary-secondary systems consume the greatest amount of energy.

Units: I-P