| Title | Design and Long-Term Performance Characteristics of Vertical Earth Heat Exchangers |
|---|---|
| Authors | Rybach, Ladislaus; Hopkirk, Robert J.; Eugster, W.; Burkart, R. |
| Year | 1990 |
| Conference | Geothermal Resources Council Transactions |
| Keywords | Heat Pumps; Engineering; Vertical Loop; COP; Vertical Heat Exchangers |
| Abstract | The vertical earth heat exchanger (VHE) is a closed circuit system to extract heat from the top 50-150 meters of the subsurface and is usually coupled with a heat pump. VHE's are being installed in rapidly growing numbers in Switzerland. Theoretical and experimental investigations supply the knowledge necessary for licensing decisions. Design parameters, VHE operational performance (also in the long term), effects of flowing groundwater, and optional summer recharge are addressed. Instrumented test facilities and numerical modeling show that ground cooling around a VHE is limited in space and time. Seasonal performance coefficients well above 3.0 can be obtained. |