TABLE OF CONTENTS At the time this article was written, Kevin D. Rafferty. P.E., was a research associate at the Geo-Heat Center, Oregon Institute of Technology, Klamath Falls. Reprinted from ASHRAE Transactions 1992, Vol. 98, Part 2.
K.D. Rafferty, P.E.
Associate Member ASHRAE
Experience with two systems, one a 360-tort (1,266-kW), 72 F (22 C) groundwater application and one a 156-ton (549-kW), 56 F (13 C) groundwater system, is described. The design, early operating history, and subsequent modifications are discussed. Experience with these systems suggests that groundwater fluid chemistry, well pump design and control, heat pump capacity control, and commissioning are critical issues in successful application.
Groundwater-coupled systems can offer significant benefits to the building owner in the area of operating energy savings. In order for the owner to fully benefit, however, it is critical that the system be carefully designed, skillfully installed, and operated according to the designer's intent. Serious consequences can result when these precautions are not observed.
To illustrate the point, this paper describes experiences with two groundwater-coupled heat recovery chiller systems. Each was installed in the last several years in newly constructed county detention facilities and shall, henceforth, be referred to as system #1 and system #2. System #1 is a 360-ton (1,266-kW), two-machine installation that provides the heating and cooling needs of a 120,000-ft 2 (11,150-m 2) county jail in eastern Washington state. This system employs a 700-gpm (44.2-L/s), 72 F (22 C) production well and injects all the groundwater into a second well.
System #2 is a single-machine,...
