Geothermal & GSHP Boreholes

Ground source heat pumps, aka geothermal boreholes can be drilled efficiently to depths in excess of 300m, with the use of automated, state-of-the-art rotary drilling rigs.

Boreholes for ground source heat pumps

ADP Group can quickly, efficiently and professionally install ground source heat collector loops using innovative and modern drilling rigs.

If you are considering installing a ground source heating system have you considered the use of vertical boreholes? Did you know that vertical borehole heat collectors operate at a higher efficiency, I.E. produce a higher heat yield per metre, than horizontal collectors?

Further benefits include the footprint required for geothermal boreholes, or lack of; borehole arrays can take up very little space, and once completed are buried below ground level. You can even build on top of completed borehole arrays!

What do we do

ADP Group can provide private domestic customers and commercial projects with a one stop solution, comprising of the following:

  • Drilling of geothermal boreholes to prescribed depths using the latest, automated, rotary drilling rigs from Comacchio.
  • Management of all arising material and drilling fluid via our track-mounted mud cleaning systems, ensuring a clean, efficient presence onsite, and no lasting legacy once the works are completed.
  • Supply & installation of high quality PE100 GSHP collector loops.
  • Tremmie grouting upon completion of installation.
  • Post-installation pressure and flow testing.


ADP Group own and operate some of the most technically advanced, state-of-the-art equipment available.

Rigs are supplied by industry leading, Italian manufacturer, Comacchio. Mud cleaning systems from American manufacturers Tibban and Elgin, with the latter supplying track mounted, self-sufficient systems.

Grouting of the completed boreholes is undertaken with grout mix/pump units from Putzmeister.

All equipment is compliant with the latest emmission stages, therefore allowing it to work within ULEZ’s throughout the UK, and ensuring that the installation of the renewable heating system is done in the most environmentally friendly way possible.

Further information on all equipment can be found on our rotary drilling rig page.


How many boreholes will I need and how deep do they need to be? (The favourite and most commonly asked one!)

Your system installer should be able to provide you with answers to these questions, however below is a very approximate calculation based on the following assumption:

Vertical borehole collectors can provide between 25 watts (in loose gravels) and 60-70 watts (in saturated stone) per metre of active collector.
(active collector denotes the actual probe that is in contact with geothermal grout)

For the purpose of this example calculation we will assume a fairly modest figure of 35 watts per metre.
(an accurate figure can be produced via a survey, this figure becomes increasing important the larger the heat pump you are installing).

And a ground source heat pump size of 12kw.
(approx heat pump size required to heat a large 4-5 bed house with good insulation)

Assumed COP of 4 (Coefficient Of Performance of 4) – 1kw in = 4kw out = net gain of 3kw.
(I.E. for every 1kw input of electricity to drive the heat pump, 4Kw of heat is produced from the ground, so a net gain of 3)

So, using our average figure of 35 watts/metre, a heat pump size of 12kw and a COP of 4 we can apply the following calculation:

12 (heat pump size) / by 4 x 3 (COP) = 9 kw or 9000 watts / 35 (watts per metre) = 258m.

This would be 2 x 129m boreholes.
(Please note however that this could be as much as 360m or as little as 150m – depending on the watts per metre produced in the given geology)

How far apart should they be?

They should be spaced at least 6m apart to prevent thermal linkage (and efficiency loss) between the boreholes.
They should be at least 5m from any buildings.

Can you drill in my garden?

Yes we can drill in your garden, so long as we can get our equipment in there – our smallest rig can access with a clear space of just 1.5m.

Does it make a mess?

It can do, with the wrong contractor! However, ADP Group have systems and measures in place to ensure we make as little mess as possible with as little disruption as possible.

ADP Group use state-of-the-art mud recycling systems such as the Mud Puppy MP170-2sc to ensure all generated waste is dealt with in the cleanest, safest, most efficient and environmentally friendly way possible.

How much does it cost?

Boreholes are usually recognised as the most expensive method, however they are also the tidiest, least disruptive and most efficient!

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