ground source heat pump, control, thermal storage
Hybrid ground source heat pump (HyGSHP) systems are gaining popularity as a means of decreasing long term energy and maintenance costs while maintaining manageable first costs. The incorporation of a supplemental heat rejecter into a standard GSHP design introduces several complexities. One of the major challenges involves determining the optimal control strategy for such a system. This paper includes a review of HyGSHP control strategies followed by a more detailed discussion of the pre-cooling strategy. This strategy incorporates thermal storage into the system in order to shift power consumption to periods with off-peak electric rates, thereby reducing operating costs. The results of a preliminary study of pre-cooling as well as plans for further research will be presented.