Title: +175=737.001_IK001_Brukermanual for Refra varmepumpe.Produktinformasjon.pdf
At steady-state conditions, there is heat transfer from the heat pump fluid to the ground. The temperature difference between the ground and the fluid in the loop provides the impetus for the energy to move. The resistance of the pipe, the grout and the ground restrict the energy movement as follows:Qc = L(tg – tw)/RWhere: Qc is the heat load (Btu/hr) L is the pipe length (feet) tg is the ground temperature tw is the fluid temperature R is the thermal resistance to heat transfer.The challenge in loop design is that the ground temperature does not stay constant. For horizontal loops, where the pipe is near the surface, the ground temperature can change seasonally with the weather. In all cases, the loop itself affects the ground temperature. For loop design, it is common to break the effects into three parts: