Slinky Loop Calculator
Loop length, trench length and land area from load and soil type.
Slinky coils pack ~10 m of pipe per metre of trench, cutting trench length ~60% at slightly lower per-metre extraction. Where digging is cheap and land available, slinkies usually win the install quote.
Slinky coiled loop: the ground supplies the load minus the compressor's contribution. Undersized loops work the first season, then progressively freeze the ground and kill the COP — size for the soil you actually have, and when in doubt, drill the test bore.
Engineering estimate from published standards and typical equipment data. Site conditions, equipment datasheets and measured data govern the real result — confirm with a qualified engineer.
Use the free Slinky Loop Calculator online — Loop length, trench length and land area from load and soil type. Runs instantly in your browser: no signup, no upload, mobile-friendly.
About Slinky Loop Calculator
Slinky coils pack ~10 m of pipe per metre of trench, cutting trench length ~60% at slightly lower per-metre extraction. Where digging is cheap and land available, slinkies usually win the install quote.
How to use Slinky Loop Calculator
- 1Enter the peak heating/cooling load.
- 2Pick the ground type honestly (test bores beat guesses).
- 3Read pipe length and the boreholes or trench the config needs.
Why use Slinky Loop Calculator?
- ✓Soil-honest extraction rates: wet clay to dry sand spans 3×
- ✓Loop length, borehole count or trench length — config-correct outputs
- ✓COP-aware: the ground supplies load minus compressor work
- ✓Undersizing warned against explicitly (frozen-loop death spiral)
Frequently asked questions
How long does a ground loop need to be?+
Pipe length = ground-side load ÷ soil extraction rate. A 10 kW system at COP 4 draws ~7.5 kW from ground; in damp loam (40 W/m) that's ~190 m of pipe — two 100 m boreholes or ~95 m of two-pipe trench. Soil moisture moves this 3×, which is why the soil selector matters most.
Vertical boreholes or horizontal trenches?+
Land decides: horizontal costs less per metre (excavator vs drill rig) but needs yard area at 1.5–2 m depth; boreholes go down 50–150 m on a parking-space footprint and reach steadier temperatures. City sites drill; farms and large plots usually trench.
What happens if the loop is undersized?+
A slow-motion failure: the ground around the loop progressively freezes (heating) or bakes (cooling) season over season, COP slides, and the 'efficient' system becomes an expensive resistance heater by year three. Size for the soil you have — and when in doubt, drill the test bore.
Does geothermal make sense in India?+
For cooling, increasingly: rejecting heat into 27°C earth instead of 45°C summer air lifts efficiency 30–50% for the same machine. Large buildings with land (campuses, hospitals) pencil first. The loop sizing here works both directions — size for the dominant (cooling) load.
Embed Slinky Loop Calculator on your website
Want Slinky Loop Calculatoron your own site? Paste this snippet into any HTML page — it's free, with no API key or sign-up. The tool loads in an iframe and keeps working exactly as it does here.
<iframe src="https://tooljolt.com/tools/slinky-loop-calculator" width="100%" height="640" style="border:1px solid #e5e7eb;border-radius:12px;max-width:680px" title="Slinky Loop Calculator — ToolJolt" loading="lazy"></iframe>Related Energy tools
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