Hybrid ground-coupled heat pump systems (HyGCHPs) couple conventional groundcoupled heat pump (GCHP) equipment with supplemental heat rejection or extraction systems. In cooling- or heating-dominated climates, the use of these supplemental systems has been shown to significantly improve the economics and energy usage of the system. However, the design and operation of HyGCHPs are significantly more complex than GCHPs and there is currently relatively little information available in this regard that is accessible to the practicing engineer.

This project solves this problem through the development of a detailed simulation-based tool incorporating physics-based models of the HyGCHP system components using the TRNSYS simulation program. The simulation model has been used to develop a distributable software tool for use by the practicing engineer, as well as to complete a parametric study of many different scenarios varying in climate, building type, and economic and physical assumptions. The results of the parametric studies demonstrate a set of general design guidelines that can be used to select an equipment configuration, size equipment, and control the equipment of a typical HyGCHP system.

Units: I-P