Status and Trends in DX Bore Field Dimensioning

In a classical Secondary Loop (SL) GSHP, the ground loop is sized independently and simply to exchange enough heat with the ground. In a DX system however, the ground loop is an integral part of the heat pump and clear design metrics is less obvious. Therefore, good design can become technology-dependant and other constraints like oil-return or valve hunting plays a role as much as thermal performance. Recent research has brought some new guidelines to improve global knowledge on this technology. This presentation discusses recent trends in ground loop design based on experimental observations and theoretical modeling.