Best possible terrain for geothermal energy

[Blond']

Hello, I am going to install a Soil / Water heat pump in Drôme, Base temperature -8 Alt 340 meters, construction standards RT2005 ++.

In my land, I only have the Marne, when there is heavy rain, I have a municipal swimming pool in front of my house; and compared to my geo cap., I would like to know which is the most interesting between Marne sand and everything coming in order to avoid that the capture freezes my ground.

Thank you

[Christophe]

I know nothing about geology, but water is a powerful thermal regulator. Wet ground will therefore freeze well after dry ground ...

That's all I can tell you on the sorry question ...

[Blond']

Ok and thank you, so if I understand correctly, it is better to have a soil promoting humidity.

[denis]

a solution: drill to have a deep depth, if you have water of course!, if you have a not too deep tablecloth this is ideal, stable temperature
for the wet ground if it is very temporary, the water can come even if cold rain, more forecast is needed, if the seller is serious he must have a technitient who knows the job

[Blond']

ok thank you for the answer, however, when it comes to drilling, it is a failure, I have no water.

[Christophe]

Well if blond is concerned about the freezing of his land is that he intends to make a horizontal collection and not vertical so even less in a well ... am I wrong?

Yes I think that a wetland is more conducive to geothermal energy ... but as I said I am not at all a specialist in the subject so there may be other constraints that cancel this advantage?

[I Citro]

2 techniques exist in waterless collection.
The vertical probe and the horizontal collection.

The vertical probe means drilling and therefore a very high budget. This technique allows sellers to offer a ground / water heat pump when the "cligeon" (customer / pigeon contraction) does not have a collection surface 1.5 times greater than the surface to be heated.
Is this technique less sensitive to movements of marly soil?

Horizontal collection is indeed a concern in marly soils which work a lot in the event of drought and which can therefore deteriorate and make the sensor flee.
In my house, in recent years all the polyethylene water pipes were leaking one after the other between the collector that goes on the street and the meters of the houses. The water company, constantly called for leaks, ended up replacing all of them. The fault lay with the marly terrain and the repeated droughts.

We can certainly overcome these drawbacks by making larger trenches for the sensors that are filled with sand in which the sensor is placed. Of course, the sand is separated from the original soil by a geotextile. Thus the sand absorbs the movements of the marly soil.

In short, you really have to want a CAP ...
I would like to take this opportunity to remind you that the CAP is not a renewable energy ... whatever the sellers say to their cligeons and although they are eligible for the tax credit ...

Edit by moderation: complement to the last remark,Geothermal, heat pumps are not (entirely) renewable energy!

[Other]

Hello

The most expensive vertical well technique, but mandatory if you are in the rock or sometimes slippery preferable the well with a special plastic loop for this use, the hole is filled with fine sand, the hole in a clay soil requires a tube , in the rock not necessary, depending on the power of the PAC it takes several holes.

For the horizontal system often it is installed at the same time on the occasion of an earthworks, house conduit buries house far from the road ect .. the conduits are placed well below the frost zone, (where the earth is 12c ) it is preferable to empty a thickness of sand deposit the conduit and to drown it in a good layer of sand, if the phreatic nape is not too hollow one tries to pose the conduit in the top of the tablecloth.

Most installers prefer to drill vertical wells very deep, for the sake of simplicity it does not deform a ground and it is close to the house

Andre

[Remundo]

Hello Blond '

To avoid freezing, not fifty solutions, bury sufficiently deeply. In addition, the more your external exchanger is "hot", in any case not very cold, the less the compressor of your heat pump will need to run. Basically, you can go from a COP of 3 with an insufficiently buried installation to a COP of almost 5 (good material required, of course) with a well-sunk installation, at around 12 ° C. Basically, you get 500W thermal for 100W of electricity supplied to the compressor.

It takes 1,50 m on average depending on the terrain. Ask the heating engineers who install this type of equipment.

For depth, nothing like vertical drilling, but it's generally more expensive. But if you have "cheap" backfill lying around and the morphology of your land lends itself to it, you can make a trench 1m deep, fill it up and have it covered with 70 cm of backfill.

Good luck.

[Blond']

Well thank you for all this information and information which will be very useful to me.