A TRNSYS/GROCS Simulation of the TECH House I Ground-Coupled Series Solar-Assisted Heat Pump System

The series solar-assisted heat pump heating system with ground-coupled storage in The University of Tennessee’s TECH House I in Knoxville, Tennessee, has been modeled using TRNSYS/GROCS and was compared to the experimental performance for the 1980–81 heating season. The simulation results were within 8 percent of the experimental measurements. Both simulation and experimental results showed that ground coupling of thermal storage led to the elimination of electric resistance backup heat and a large reduction in the peak heating demand of the house. Results of a parametric study showed that, in general, a ground-coupled storage tank performs better than a storage tank placed outdoors in the Knoxville area. Application of a next generation heat pump resulted in the most significant impact on the seasonal performance factor. As expected, higher performance collectors and larger collector areas led to higher system seasonal performance. An economic analysis showed that the series solar heat pump system cannot economically compete with the stand-alone heat pump system in the Knoxville area.