GchpCalc is Program C in the paper. In larger buildings the ground loop length required for the cooling is often much greater than length required for heating. GchpCalc can size a fluid cooler or cooling tower to compensate if the designer chooses to specify a smaller ground loop. Automatic Bore Resistance Version 2.2 of GchpCalc required two tables to find the thermal resistance of the U-tube, bore, and grout. Version 3.1 incorporates the results of research at South Dakota State.
Users can enter bore hole size, grout conductivity, and U-tube size for automatic calculation.
The older manual method can also be used if novel ground loop designs are encountered. Loop Pump Sizing Version 2.2 of GchpCalc considered the impact of pump power on overall system efficiency. Although this feature alerted designers to potential waste, users were required to guess pump size before the ground loop was designed. Version 3.1 only requires the user to input expected system head loss. Pump size is selected and pump motor demand is calculated.