1984-85 Annual Performance Testing and Analysis of Two Horizontal Coil Ground-Coupled Heat Pump Systems: Final Report

摘要

Performance of two different ground coupled heat pump (GCHP) installations at the TECH site at the University of Tennessee is reported for the 1984 to 1985 heating season and the 1985 cooling season. One system, located in TECH House I (a single family residence with design heating and cooling loads of 30,000 and 22,000 Btu/hr, respectively), is a hydronic heating only unit (field modified for cooling operation) which has been operating continuously since 1982. The second system is a water-air unit located in TECH House V (a single family residence with design heating and cooling loads of 24,000 and 16,000 Btu/hr, respectively). It was designed and installed by a private sector participant in November 1984 and has been evaluated over one calendar year. Seasonal performance factors of the TECH House I system were found to be 2.23 and 1.51 for heating and cooling, respectively. The corresponding seasonal performance values of the new GCHP system in TECH House V were found to be 2.84 and 2.59. Previous seasonal performance factors of the TECH House I system were found to be 2.6 (heating) and 1.1 to 1.3 (cooling). The values reported for the 1984 to 1985 winter are different primarily due to the use of sand as a backfill material and fewer cooling degree days during the 1985 summer. System V performance is superior to system I due to an increased length of ground coil and a heat pump unit having better cooling performance characteristics. A comparison of the sesonal peak load required by heat pump in TECH House III (a house with design heating and cooling loads comparable to TECH House I) showed a reduction of 8 kW. Thus, the GCHP system should show a significant savings should the utilities institute residential peak demand pricing. (ERA citation 12:028748)