Ground water integrated heating, ventilation, and air-conditioning (HVAC) systems have been operating in the Northwest for nearly 50 years, and experiences with the early central plant installations have been well documented in ASHRAE literature. Focuses on two of the more recent systems. Both of unitary design, one serves a high school in northern California and the other a high school in western Oregon. The California site, a 144-ton (506kW), 57degF (14degC) groundwater system in operation for two years, demonstrates the importance of verifying the groundwater resource prior to final mechanical design. The Oregon site, a 118-ton (415kW) system, employs a 54degF (12degC) production well and an injection well. It has been in operation for approximately eight years. The energy performance and maintenance requirements are detailed. Experience with these two systems indicates that properly designed groundwater systems are efficient, low maintenance, and cost-effective.

KEYWORDS: year 1996, soil, water heat pumps, schools, USA, heating, ventilation, air conditioning, building services, case studies, performance, maintenance, economics, costs, energy conservation, operation, energy consumption