3132 -- Performance Test of a Direct Expansion Heat Pump System PDF

In this paper, results are given for a direct expansion heat pump system that is uniquely coupled to the earth through a heat transfer concentrator (GLHXC, Ground Loop Heat Exchanger Concentrator). In effect, the system reduces several of the thermal resistances associated with the heat flow paths in other types of ground-coupled heat pump systems. Performance results for the GLHXC system are given for both cooling and heating operation based on a one-year test period. The results are compared to experimental data obtained from four other types of earth coupled configurations (horizontal pipe, pebble bed, surface tank, and a closed-loop vertical well) and an air-source heat pump tested at a research laboratory (AERL). The heating season COP for the GLHXC system was 4.2 and the cooling season COP was 3.1. When compared to the other heat pumps tested at AERL, this represents an improvement in performancer anging from 7% to 50%.

Units: Dual