Welcome to LoopLink PRO
LoopLink PRO is web-based software for commercial geothermal system design. It follows the general design procedure outlined in Geothermal Heating and Cooling: Design of Ground-Source Heat Pump Systems (Kavanaugh and Rafferty, 2014), which is as follows.
- Calculate peak zone cooling and heating loads and estimate off-peak loads.
- Estimate the annual heat rejection into and absorption from the loopfield to account for potential ground, groundwater, or reservoir-water temperature change.
- Select the preliminary loop operating temperatures and flow rate to begin optimization of first cost and efficiency (selecting temperatures near the normal source temperature will result in high efficiencies but larger and more costly ground loops).
- Select heat pumps to meet cooling and heating loads and locate units to minimize duct cost, fan power, and noise.
- Correct heat pump performance at rated conditions to actual design conditions (Chapter 2). Note that some designers prefer to reverse the order of Steps 5 and 6.
- Arrange heat pumps into ground-loop circuits to minimize system cost, pump energy, and electrical demand (Chapters 4 and 6).
- Conduct a site survey. For closed-loop GSHPs, conduct a thermal property test to determine ground thermal properties and drilling conditions (Chapter 3). For small projects a survey of geological reports can be used to conservatively estimate these values.
- Assess outdoor heat exchanger options. For closed-loop GSHPs, determine and evaluate possible loopfield arrangements that are likely to be optimum for the building and site (bore depth, separation distance, completion methods, annulus grout/fill, and header arrangements). Include subheader circuits (typically 5 to 15 U-tubes on each) with isolation valves to permit air and debris flushing of sections of the loopfield through a set of full-port purge valves.
- Determine the optimum ground heat exchanger dimensions with calculations provided by LoopLink PRO. Recognize one or more alternatives that provide equivalent performance and that may yield more competitive bids.
- Evaluate alternative designs: loopfield arrangements, operating temperatures, flow rates, heat exchanger dimensions and materials, grout/fill materials, etc.
- Lay out interior piping and compute head loss through the critical path, and select pumps and control method.
- Determine system efficiency and consider modifying the water distribution system if pump demand exceeds 10% of the system total demand, modify the air distribution system if fan demand exceeds 15% of the system total, select more efficient pumps, or redesign ground loops (Chapter 7).
These publications will serve as excellent resources for the GSHP system designer:
- ASHRAE HVAC Applications Handbook (2015)
- Geothermal Heating and Cooling: Design of Ground-Source Heat Pump Systems
- Ground Source Heat Pump Residential & Light Commercial Design and Installation Guide
- Grouting for Vertical GHP Systems
- Closed-Loop Geothermal Heat Pump System Design & Installation Standards
- Second Edition Handbook of PE Pipe
- Importance of Thermal Grout Conductivity