Air Heat Pumps ConstructionAir heat pumps for your home

Air-to-air heat pumps: the principle

The Principle

The principle of the heat pump is to capture the calories

present in the outside air.

This is the principle of Thermodynamics.

The calories present in the outside air are transported to the interior of the house thanks to a closed and airtight refrigerating circuit.

The installation is composed of an outdoor unit which will draw the calories present in the air to restore them in the indoor air.

There are two types of indoor units:

The ductable ones: the indoor unit ensures the distribution of heat via an aeraulic distribution system.

The Splits or consoles: indoor units with direct emission.

All air-to-air heat pumps, commonly known as air-conditioning, are reversible; in other words, they can also be used to cool the home.


Since the energy contained in the air is free, you only consume the energy needed to operate the heat pump.

By installing a heat pump, you can reduce your energy consumption for heating your home by a factor of 3.

How Air-Air heat pumps work

How does it work?

The heat pump is composed of a compressor, two exchangers :

one to capture energy from the outside (evaporator), the other to return it to the inside (condenser) and an expansion valve.

The compressor will suck in the refrigerant, which is in the form of gas at low temperature.

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 air is 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 nivAir in the homes to heat them.

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

In fact, for every 1 kWh of electrical energy consumed,

3 to 4 kWh of thermal energy are returned.

The heat pump thus makes it possible to cover 100% of the heating needs of a dwelling.

consuming only 30% 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.

Air Heat Pumps Construction

The installation of an Air-Air heat pump: implementation

Mise and oeuvre

The installation of a heat pump during renovation cannot be carried out by

only if there is an existing central heating system.

The outdoor unit should be installed outdoors on a flat, stable floor (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.

Air-to-air 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, usually 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.

It is mandatory to check the refrigerant circuit for leaks every year.

and must be carried out by a company holding the prefectoral approval or the attestation of capacity.

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

Air-Air heat pumps: Technical data

Technical characteristics


First of all, the dimensioning of the heat pump units is of paramount importance.

A poorly dimensioned heat pump will not cover the heating needs of the home in case of undersizing or will run the risk of short-cycling and electrical overloads in case of oversizing leading to a lower COP and shortening the service life of the equipment.

The dimensioning of the heat pump is based on the Kilowatt heat output (heat production capacity of the heat pump).

How do you calculate the power of the indoor units of the heat pump required?

Simply multiply the volume of each room to be heated by the difference between the lowest outdoor temperature and the desired indoor temperature, multiplied by the insulation coefficient of the house ( =1 if the house is normally insulated, 0.95 if it is very well insulated, 1.2 if it has air leaks, …).

Example: we wish to heat 1 room of 12m² and a room of 50m, each with a ceiling height of 2.50m, where it is -9°Celsius at least in winter, where we wish to have an interior temperature of 20°C, which is well insulated (insulation coefficient 0.95). The powers of the indoor units will be :

1st room: 12m² x 2.5 x (20-(-9))*0.95 = 826.50 or 0.82Kw.

2nd room : 50m² x 2.5 x (20-(-9))*0.95 = 3443.75 or 3.44Kw.

The outdoor unit is dimensioned by the sum of the powers of the indoor units. In the above example : 0.82 + 3.44 or 4.26kw.

In addition to the dimensioning of your heat pump which is essential in the efficiency of the installation,

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.Air Heat Pumps Construction

How much does it cost to install an Air-Air heat pump?

What is the cost?

The installation of an AIR HEAT PUMP is

an important investment that will be amortized by the energy savings made.

For a turnkey installation of a heat pump, it is necessary to plan between 65 and 90€ per m².

This includes the outdoor unit, the indoor units, the various supplies as well as labor for installation and commissioning.


You divide by 3 your energy consumption for heating your home. This can represent several hundred euros per year.

Air-Air heat pump: environmental impact

Environmental impact


By heating your home with a heat pump, in addition to the significant savings, the amount of energy not consumed compared to conventional heating significantly protects our planet.

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

Using the calories present in the air means contributing to the protection of our environment.

Did you know that? According to article R131-20 of the Construction Code, the use of air conditioning is prohibited when the indoor ambient temperature is below 26°C.