TECH House I Horizontal Coil Ground Coupled Heat Pump: 1983 Cooling Season Performance

摘要

Performance of the ground-coupled heat pump system in TECH House I at the Tennessee Energy Conservation in Housing Facility is reported for the summer of 1983. The overall seasonal performance factor (SPF) was 1.11 with the system located within the conditioned space. If the system had been outside the conditioned space, an SPF of 1.31 would have been realized. This low performance level, below that of a conventional air-to-air heat pump, is primarily due to poor performance of the ground heat exchanger. Degraded soil heat transfer characteristics due to drying and the occurrence of voids around the pipe in the trench backfill were primary reasons for poor performance. In addition, it appears that the underground coil length needs to be increased in order to match the peak cooling loads of the house. The sensible load on the house was met by the system only for ambient temperature below 98 exp 0 F. The latent load was often not met because the inside coil temperature was not sufficiently below the dew point temperature of the inside air. (ERA citation 09:026212)