Chat with Sunniva on WhatsApp
Skip to Content
Geothermal

How much ground does your building need?

On a ground-source job the heat pump is the easy part. What decides the project is the loop — how many metres of bore, how many holes, how much land, and what it displaces. Move the sliders and all four move with them. Nothing is hidden: every assumption is a slider, and the saved sheet records exactly what was used.

The load

What the plant has to carry, and for how long.

Cooling load 100TR
The design cooling load the plant has to carry.
Heating or hot water load 0kW
Anything the same plant will heat — hot water, a pool, winter heating. Leave it at zero for cooling only, but read the balance note in the results: a loop that is only ever charged is the hardest one to keep performing.
Hours a year on heating 0hours

The ground

Two things matter: how warm it is, and how well it conducts.

Nearest city
Seeds the ground temperature from the annual mean air temperature — the reason a loop does not care what today is like. Indicative; a survey settles the real figure.
Undisturbed ground temperature 28°C
Heat exchange per metre of bore 42W/m
THE number the whole loop length turns on. The chips above seed it; a thermal response test on the actual plot settles it.

The loop

Bores, trenches or a well — they are sized in different units.

Bore depth 90m
Deeper bores need less land and reach steadier ground, but cost more per metre and depend on what the rig can take.
Spacing between bores or trenches 5.0m
Too close and they steal from each other — which is exactly what goes wrong on a cooling-dominated site.

The plant

Ground-source performance, and the pump that is usually forgotten.

Ground-source COP, cooling 5.2
Water-to-water plant against a steady ground loop, so it holds this on the hottest afternoon — which is exactly when an air-cooled machine is at its worst.
Ground-source COP, heating 4.4
Loop pump power 6% of compressor
The circulator that pushes fluid round the ground loop. Real, and usually left out of comparisons that flatter geothermal.

What you are replacing

Change these to your own tariff and your own system.

Its COP at design 3.05
Seasonal, not the catalogue peak. An air-cooled machine loses most of its rating on the day you need it most.
Full-load hours a year 2400hours
Not running hours — the equivalent hours at FULL load. A building that runs 3,000 hours at 60% average load is 1,800 full-load hours.
Electricity 9₹/kWh
Cooling tower and carbon assumptions change only if you know why
Cooling tower evaporation 1.5L/kWh rejected
About 1.5 litres evaporates for every kWh of heat a tower throws away — the latent heat of water, near enough.
Cycles of concentration 4
How many times the tower water is reused before it is dumped. Makeup is evaporation × COC ÷ (COC − 1).
Whatever figure you have — ours or anyone else’s, installed. Nothing is sent anywhere until you fill in the form below.
Grid electricity carbon 0.71kg CO₂/kWh
The Indian grid average. Lower it if you have rooftop solar or a green tariff.
Diesel carbon 2.68kg CO₂/litre
LPG carbon 2.98kg CO₂/kg
PNG carbon 1.9kg CO₂/SCM
Coal / biomass carbon 1.8kg CO₂/kg
Swings hugely with grade. Set it near zero for biomass, which is usually counted as biogenic.
The ground loop
—
Rejected to ground
—
Drawn from ground
—
Plant duty
—
Land the field needs
—

Cost to run for a year

You would save
—

What it pays back, and what it stops

Pays for itself in
—
Carbon avoided
—

Want this loop checked against your plot?

Your name, phone and email go on the saved sheet and let our team confirm the load, the formation and the loop against the actual site. All three are needed before the sheet can be sent or saved.

Print / save as PDF

How this is worked out

  • The ground has to take more than the room load. A cooling machine rejects the load plus the compressor work it took to move it: Q × (1 + 1/COP). Heating is the mirror image — the ground gives up the load less the compressor work, because that work also ends up in the water. The loop is designed on whichever of the two is larger, and in India that is almost always the rejection side.
  • Loop length = heat exchanged ÷ watts per metre. That watts-per-metre figure is the entire design, and it is the one thing a website cannot know: it depends on the formation, on whether groundwater moves through it, and on how many hours a year the loop runs. The chips seed it from typical values; a thermal response test on the actual plot settles it, and the length moves proportionally when it does.
  • An open bore-well is sized on flow, not length. The water carries the heat out instead of the ground conducting it, so the design number is m³/h: Q × 0.86 ÷ the temperature rise. What it needs is a yield that holds through the dry months and a discharge the groundwater authority will permit.
  • The annual balance is a design input, not a footnote. A cooling-only site pushes heat into the ground every year and takes almost none back. The ground warms, the entering water temperature climbs and the COP falls — slowly, over years, which is why it is so often missed. The results panel works out the imbalance and says so when it is large.
  • The comparison includes the pumps. Geothermal carries its loop circulator; the air-cooled options carry their condenser fans; the water-cooled option carries its tower, its condenser pump and the makeup water it evaporates. Comparisons that leave those out flatter whichever side they favour.
  • Full-load hours, not running hours. A building open 3,000 hours at 60 % average load is 1,800 full-load-equivalent hours. Using running hours overstates every saving on this page.
  • No Sunniva model is named and no Sunniva price is used. Ground-source plant is built to the site, so this tool gives a duty to quote against. The payback box uses whatever installed price you type in — ours or anyone else’s.
  • Payback is simple payback — the price you type in, divided by the annual saving. No finance, no maintenance, no discounting, and no price of ours is assumed or disclosed. Carbon is the displaced fuel’s emissions minus the electricity the heat pump draws, at the Indian grid average of 0.71 kg CO₂ per unit. Every factor is a slider, and the saved sheet records what was used.
  • Indicative only. Formation, groundwater, drilling access and the local water authority all change the answer — confirm with Sunniva Encon LLP before ordering.
Geothermal loop sizing Sunniva Encon LLP

Calculated for

—

What you entered

Result

Required capacity
—
—

Running cost & savings

How this was worked out

Talk to Sunniva

Sales QR codeSalesWhatsApp our sales desk
LinkedIn QR codeLinkedInFollow Sunniva Encon
YouTube QR codeYouTubeSee the machines running
Review us QR codeReview usRate us on Google
Contact
+91 93213 65103
sales@sunnivaencon.com
www.sunnivaencon.com
Office
C‑443, Oshiwara Industrial Centre Premises CHS, New Link Road, Goregaon West, Mumbai
© 2026 Sunniva Encon LLP. The design and code of this calculator are our copyright. Results are indicative and offered in good faith — the method is set out above. Confirm the final selection with us before ordering.
WhatsApp Icon 1