DOE EERE Research Reports

The survey identified four basic WSHP system configurations. Nomenclature for the configurations was established based on the nature of the liquid flow path serving each WSHP and the energy source/sink that maintains the liquid within acceptable temperature limits for efficient and reliable WSHP operation. The survey identified two liquid flow path types. In the "open-loop" flow path, liquid from the environment is discharged back to the environment through operating WSHP. In the "closed-loop" path, liquid is contained in a closed system and recirculated through the WSHP. The survey found only one generally accepted open-loop source/sink for commercial applications, namely, groudwater. The three generally accped closed-loop source/sinks identified were the heater/rejecter, ground-coupling, and environmental water source (surface water or groundwater). Each basic WSHP system configuration has several variations. The paper describes each of the four basic WSHP system configurations and their major variations.

A survey of WSHP system application characteristics was also performed. The paper presents the results of this survey in the form of a series of generalizations intended to assist designers in selecting the most beneficial WSHP system configuration for a given application. It is believed that WSHPs are suitable for many more commercial applications than common knowledge would indicate, partly because application evaluations are not always performed based on the most beneficial WSHP system configuration.