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Heat Pump

A heat pump is a heating installation that draws heat from the outside (the ground or the air) and transfers it to the home through heating appliances: radiators, underfloor heating, etc. It's an alternative to standard boilers and creates substantial energy savings.

What is a heat pump?

Just like a wood, oil or gas boiler, a heat pump is a heating solution that can be fitted in a home. There are various types of heat pump, which collect heat from different sources to heat a home. In some cases the heat pump also produces hot water, and there are "reversible" devices that also produce cool air via an air conditioning system.

There are three types of heat pump. An aerothermal heat pump draws heat from the outdoor air, a geothermal heat pump uses the ground as a heat source and a hydrothermal heat pump draws heat from a groundwater table. These main categories of heat pump are then subdivided according to the heat distribution medium: the air when indoor air is being heated and water when hot water is transferred into a heating system or being produced.

How does a heat pump work?

Here's how the different types of heat pump work depending on the heat source used and the chosen distribution medium.
  • Aerothermal heat pumps
-Air-to-air aerothermal heat pumps: these draw heat from the outdoor air and transfer it to the home through a fan coil system. They can also supply cool air to an air conditioning system during the summer.
-Air-to-water aerothermal heat pumps: these distribute heat to a home through hot-water radiators or hot-water underfloor heating and can be connected to a pre-existing central heating system.
  • Geothermal heat pump
-Ground-to-ground geothermal heat pumps: these capture heat (or cold) from the ground using a sensor and buried pipes. The sensor can be horizontal, in which case the installation requires a huge plot 1.5 to 2 times the surface area to be heated, or vertical, in which case very deep probes (several dozen metres) are needed to draw the heat from the ground. Although geothermal heat pumps are effective, they only work with low-temperature radiators or underfloor heating.
-Ground-to-water geothermal heat pumps: the principle is the same but the energy captured is used for hot-water heating.
  • Hydrothermal heat pumps
This type of heat pump captures the heat from an underwater groundwater table using a vertical probe. This solution is therefore a better option if your land has a sufficiently large water supply. This very effective heating system only works with low-temperature hot-water radiators or hot-water underfloor heating.

Save on heating with a heat pump

Because heating accounts for a big part of a household budget, it's essential to fit an economical heating system in order to make energy savings. Although the energy produced using a heat pump isn't considered a renewable energy because it runs on electricity, it nevertheless uses a free energy source (the land, air or water) and transfers more energy than it consumes.

A heat pump is therefore energy efficient and the initial outlay quickly pays for itself if your home is well insulated. When running, an "air-to-air" heat pump only requires a minimum of electricity to circulate the fluid carrying the heat. Although backup heating may be necessary in very low temperatures with an aerothermal heat pump, it's thought that a heat pump cuts your heating bill by two thirds.

It usually takes three to five years to offset the cost of installation. Meanwhile, a geothermal heat pump is effective regardless of the outdoor temperature, as is a hydrothermal heat pump, which draws heat from a groundwater table in which the water is usually at a consistent temperature.

A heat pump therefore has many advantages over a gas or oil boiler, notably in terms of the cost of power consumption. Discover all our products

Heat pumps and the tax credit

One of the advantages of a heat pump for heating your home is that you're also eligible for the "CITE" (energy transition tax credit) that the French government grants to people who spend money on energy refurbishment works in their home. This subsidy, which is subject to conditions, allows you to make further savings by deducting from your income tax some of the cost of installing your heat pump.

To receive it, you must be a homeowner or tenant and fit a heat pump in your main residence, which must be more than two years old. To be eligible, the heat pump installation must also be carried out by a professional who is environmentally certified ("RGE").

Except for "air-to-air" heat pumps, which have not been classed as efficient enough, the cost of installing a heat pump is eligible for the tax credit. As such, up to 30% of the installation costs can be deducted from your tax, whether you're installing a geothermal, hydrothermal or air-to-water aerothermal heat pump (provided that its COP or coefficient of performance is higher than 3.3).

Other subsidies for installing a heat pump

As well as the energy savings made and obtaining a tax credit, investing in an energy-efficient heat pump may make you eligible for other subsidies. The French government wants to encourage the public to use cleaner heating methods and undertake energy refurbishment works.

These include the Energy Bonus granted by the government and its CEE certified partners that have signed the commitment charter, as well as the interest-free eco-loan granted without means-testing, which can be used to fund energy refurbishment materials and equipment, as well as installation by a professional. You are also eligible for a lower VAT rate of 5.5% on the cost of fitting an air-to-water heat pump, a water-to-water heat pump or a geothermal heat pump. The French national housing improvement agency (ANAH) can also help you with the cost of installing a heat pump system. To receive these subsidies, the heat pump must be installed by a professional who is environmentally certified ("RGE").

The drawbacks of heat pumps

Because they're ecological and energy-efficient, heat pumps have a lot of benefits, although there are also a few drawbacks. Firstly, your home must have a garden, which is required for installing the external unit, as well as the capture network in the case of a geothermal heat pump. In this case, installing your heat pump will also involve major work being carried out, preferably during construction or major renovation works.

An air-to-air or air-to-water heat pump system often means you need to have backup heating to contend with the coldest periods of winter, as the system can't function at very low temperatures (usually below -10°C). It's up to you to decide whether it's worth fitting a heat pump based on the temperature of the area where you live during the winter.

If you choose a heat pump of more than 12 kW, it must be inspected by a professional every year. An air-to-air heat pump must also be regularly maintained and the filters of the fan coils need to be cleaned. In addition, if your heat pump is also used for air conditioning in the summer you'll need to regularly empty the accumulated condensation from the tanks.

Heat pumps: power and coefficient of performance

A heat pump's COP (coefficient of performance) is used to measure the ratio between the electrical power used by the heat pump and the emission of heat. This indicator can be used to compare the effectiveness and energy efficiency of different models of heat pump, or to compare a heat pump's performance with that of another type of heating.

Nevertheless, for an accurate comparison using the COP it's necessary to use the annual coefficient of performance rather than the nominal COP indicated by manufacturers, i.e. the average of all COPs recorded over an entire year. This allows you to determine a heat pump's actual performance, regardless of the outdoor temperature, and you can also assess the cost of your electricity bill. Nevertheless, the nominal COP is used to determine eligibility for the interest-free eco-loan.

In reality, a heat pump's coefficient of performance indicates the number of kWh output per 1 kWh of electricity used. This is usually between 2 and 3 for an air-to-air heat pump and between 3 and 4 for a geothermal heat pump, meaning that the latter uses much less electricity.

The thermal power produced by a heat pump, another performance criterion, is also important. This defines the heat pump's heat production capacity and is usually between 5 and 20 kW.

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