Air conditioners are usually used to cool the indoor air, in one or more rooms simultaneously, by taking the heat from the interior of the house to discharge it to the exterior.

Air conditioner - in cooling mode

Air conditioner in colling mode

If an air conditioner can produce cold and cool the home in summer, it can also be used to heat it in winter. This dual function is performed by reversible air conditioners, or by heat pumps.

Reversible air conditioner - in heating mode

Air conditioner in heating mode

There are different families of air conditioners. In addition to single-unit air conditioners that are not currently certified by Eurovent Certita Certification, there are two types of air conditioners:

  • “split” (or single-split) composed of an outdoor unit and an indoor unit
  • “multi-split” composed of an outdoor unit and several indoor units.

In the case of reversible “multi-split” air conditioners, all indoor units operate simultaneously in the same mode, either “cooling” mode or “heating” mode. It is not possible to have some indoor units running in “cooling” mode and others in “heating” mode. (For this feature: see Variable Refrigerant Flow (VRF) programme)

Depending on their location, there are several types of indoor units:

  • Wall or “split” units (1)
  • Consoles (2)
  • Ceiling units (3)
  • Cassettes (4)


Working principle

An air conditioner is composed of 5 elements:

  1. A liquid refrigerant circulating inside the air conditioner. This fluid changes state in each component in order to convert the energy taken from the home and discharge it as heat to the exterior.
  2. An evaporator, also called "exchanger". By recovering the calories present in the outdoor air, it converts the liquid refrigerant into a gaseous state by evaporation.
  3. A compressor, powered by a motor (electric), increases the temperature of the fluid coming out the evaporator, while increasing its pressure.
  4. A condenser, also called “exchanger”, transfers the energy produced during the change of state of the fluid to the outside environment. Condensation converts the gas coming out of the compressor into a liquid.
  5. An expansion valve reduces the pressure of the liquid, which comes out of the condenser, so that the liquid refrigerant can start a new cycle.

In the case of a reversible air conditioner, or air-air heat pump, the operation is reversed. The evaporator then becomes a condenser, and conversely for the condenser. The device can thus capture heat from the outdoor air and transfer it to the interior.

Benefits of a split or multi-split air conditioner

An air conditioner draws its source of energy for free from nature. Constantly replenished by the sun, wind and precipitation, the calories taken from the environment (Air) remain inexhaustible.
Following new European regulations promoting the sale of high-performance heating equipment, the performance of air conditioners is changing: the efficiency of an air conditioner long characterised by instantaneous efficiency called EER for “cooling” mode and COP for “heating” mode is now characterised by a performance that reflects the efficiency of the air conditioner throughout the year. This is known as SEER (seasonal energy efficiency ratio for cooling mode) and SCOP (seasonal coefficient of performance for heating mode).
Finally, this seasonal performance is associated with energy efficiency classes (A++, A+, etc.) making it easier to compare air conditioners with each other.

    Air conditioner label

    Compare to make the right choice

    It is very easy to make the right choice: just compare the products. But when product performance is not certified, this becomes impossible.
    Certification makes it possible to compare objectively.

    • The product performance is evaluated according to the same criteria, and the results are expressed in the same unit of measurement, regardless of the country where the products are manufactured or marketed.
    • A certified product has its performance verified by an impartial, independent and competent accredited body.
    • Certified products comply with standards.
    • A product whose performance is certified will work according to the specifications stated by the manufacturer.

    The performances we certify

    • SEER (Seasonal Efficiency Energy Ratio)
    • SCOP (Seasonal Coefficient of Performance)
    • dBA (A-weighted decibels) = Used to measure environmental noise.