GEOTHERMIE Heat Pumps ConstructionGeothermal heat pumps for your home

Geothermal heat pumps: the principle

The Principle

The principle of the GEOTHERMIE heat pump is to capture the calories present in the ground.

To do this, heat sensors buried in the ground are used.

The calories present underground are transported to the interior of the house thanks to a closed and watertight refrigerating circuit.

The installation consists of a collector that takes the calories present in the ground and sends them to a heat pump.

The captured energy will be multiplied by 4 and will then be conveyed into the central heating circuit of the house and possibly into the domestic hot water circuit.


The energy contained in the air being free, you only consume the energy necessary for the operation of the heat pump.

The installation of a heat pump allows you to divide by 3 your energy consumption for heating your home.GEOTHERMIE Heat Pumps Construction

The operation of geothermal heat pumps

How does it work?

The geothermal heat pump is composed of a buried collector either in vertical or horizontal spreading and a heat pump.

The compressor of the heat pump will suck in the refrigerant, which is in the form of a low-temperature gas. By compressing the gas, its temperature will rise along with its pressure.

The hot gas will be directed to an exchanger (called a condenser) in which a fluid to be heated circulates.

The heat of the environment present in the ground is a free energy that is constantly renewed thanks to solar radiation and rainfall. The heat pump takes this heat from the environment and transfers it to a higher temperature level in the homes to heat them.

It is during these operations that the very low consumption of electrical energy takes place.

In fact, for 1 kWh of electrical energy consumed, 3 to 4 kWh of thermal energy is released.

The heat pump can therefore cover 100% of the heating needs of a dwelling by consuming only30% of electrical energy.

The remaining 70% is drawn from the air while preserving the environment.

The heat pump is a high-performance solution for producing heat.

from free energy drawn from the environment.

The installation of a geothermal heat pump: implementation

The installation of a GEOTHERMIE heat pump in renovation can only be carried out if there is an existing central heating system.

A garden large enough to bury the horizontal collectors must be available in the case of a horizontally applied ground-source heat pump.

A vertically installed ground-source heat pump requires the installation of two probes between 20m and 80m deep to capture heat from the earth.

The outdoor unit of the heat pump must be installed outdoors on flat, stable ground (ideally a concrete slab) in a dry, ventilated area.

The indoor unit is usually placed in replacement of your old boiler to facilitate its connection with the existing heating circuit and as close as possible to the outdoor unit to limit the distance of refrigerant circulation between the two.  In fact, the refrigerant has an environmental impact 30 times greater than that of CO2 on the environment. Its use must therefore be used sparingly and controlled in a sealed circuit.

Geothermal heat pumps work with conventional radiators as well as with low or high temperature emitters.

It is also possible to install a heat pump as a boiler backup.

The current boiler is kept and will then be used as a backup on very cold days when the heat pump is no longer working (above a certain outdoor temperature, generally between -10 and -15°C).

The installation must be carried out by a professional.

Remember to check that your installer has the QUALIPAC LABEL, an independent label that carries out regular checks on installers’ sites.

A heat pump requires annual maintenance to optimize performance and increase its lifespan.

Checking the tightness of the refrigerant circuit every year is compulsory and must be carried out by a company holding the prefectoral approval or certificate of capacity.

Before installing your heat pump, check that your installer has this certificate so that he can carry out the maintenance of your heat pump.GEOTHERMIE Heat Pumps Construction

Geothermal heat pumps: Technical specifications

Technical characteristics

The COP: COEFFICIENT OF PERFORMANCE is the reference unit of a heat pump.

What is the COP?

It is the power restored in relation to the power consumed.

That is to say, the quantity of Kilowatt-hours produced for 1 kwh consumed.

The higher the COP, the more efficient the heat pump.

Attention, to benefit from the tax credit, the COP must be greater than or equal to 3.3.

 How much does it cost to install a geothermal heat pump?

What is the cost?

The installation of a GEOTHERMAL HEAT PUMP is an investment at a very high cost.

which will be amortized by the energy savings achieved after many years.

For a turnkey installation of a Geothermal heat pump with horizontal spreading, between 85 and 135€ per m² should be planned.

For a turnkey installation of a Geothermal heat pump with vertical spreading, between 145 and 185€ per m² should be planned.

This includes the collectors, the heat pump, the various supplies as well as labor for installation and commissioning. To this must be added for a new construction, the price of the underfloor heating (the slab + the heating circuit) or the radiators.

Tax credit for the installation of a geothermal heat pump A REDUCED INVESTMENT GRACE TO THE TAX CREDIT.

The French state wishes to help the development of the use of renewable energies.

26% tax credit for heat pumps whose purpose is to produce heat.

Attention only heat pumps with a COP greater than or equal to 3.4 are eligible for the tax credit.

On what amount of expenses does the tax credit apply?

The tax credit covers the price of equipment and materials, excluding labor, meeting the characteristics.

What is the amount of expenses eligible for the tax credit?

For the same taxpayer and the same dwelling, the amount of expenses eligible for the tax credit may not exceed, for a period of five consecutive years between January 1, 2010 and December 31, 2015, the sum of € 8,000 for a single person, widow or divorced and € 16,000 for a couple subject to joint taxation. This sum is increased by €400 per dependant within the meaning of Articles 196 to 196B.

To find out your rights to the tax credit, you are advised to refer to the provisions of article 200 quater of the General Tax Code.

For the application of this measure, it is strongly recommended to refer to :

The website (page on the tax credit)

Article 200 quater of the General Tax Code, Article 90 of the 2005 Finance Act, Article 83 of the 2006 Finance Act, Article 109 of the 2009 Finance Act and Article 80 of the 2010 Finance Act.

The tax instructions 5B-26-05, 5B-17-06 and 5B-17-07

The decrees of February 9, 2005, December 12, 2005 and November 13, 2007 issued for the application of articles 200 quater and 200 quater A of the general tax code relating to capital expenditure on the main dwelling and amending annex IV to this code

Sections 81 to 83 of the 2012 Finance Act


Some regions, town halls or the ANAH also subsidize the installation of photovoltaic panels by granting financial aid. Find out more directly from these administrations or from your ESPACE INFO ENERGIE.

Tax credit for the installation of geothermal heat pump A VAT REDUCED TO 7% FOR HOUSINGS OVER TWO YEARS.

Tax credit for the installation of a geothermal heat pump A QUICKLY AMORTIZED INVESTMENT THANKS TO THE ENERGY SAVINGS EFFECTED:

You divide by 3.3 your energy consumption for heating your home.

This can represent several hundred euros per year.

Geothermal heat pump: environmental impact

Environmental impact


By heating your home with a geothermal heat pump, in addition to significant savings,

the amount of energy not consumed compared to conventional heating significantly protects our planet.

Even if the geothermal heat pump requires electricity consumption, the environmental impact is divided by three due to the low electricity consumption of the heat pump.

Three times less electricity consumed means three times less electricity to produce and therefore three times less greenhouse gas emissions.

As a boiler replacement, it is 100% savings of fossil energy (fuel oil, coal, gas) which are in the process of being depleted.

Using the calories present in the soil is to contribute to the protection of our environment.