Air conditioning energy use: the figures and the 26 °C rule

In France, home air conditioning uses about 4.9 TWh a year, close to 1% of household energy use according to ADEME, the French energy and environment agency: far less than heating. What drives your bill is how you use it. Set it to 26 °C, stay within 5 to 7 °C of the outdoor temperature, and keep the unit serviced.

AC using too much power or cooling badly? Call +33 1 89 70 15 36 (01 89 70 15 36 from a French phone), 7 days a week, 24 hours a day, or write to us from the contact page. To choose an efficient, correctly sized unit, read our complete guide to air conditioning installation in Paris.

Planning air conditioning? Installation, servicing and repair, building approval included: see our air conditioning service in Paris.

How much energy air conditioning really uses in France

According to ADEME, air conditioning in France uses 15.5 TWh a year across all sectors (offices and shops, industry, homes). Homes account for 4.9 TWh, about 1% of household energy use.

This modest figure has several explanations:

• ownership is still limited: 18% of households in 2023 and 24% in 2025, according to ADEME;
• most of it is in houses: according to ADEME, three quarters of home air conditioning consumption comes from detached houses, not flats;
• a short season: a few weeks of use a year in most regions.

Globally, the picture is different. According to the International Energy Agency (IEA), air conditioners and fans account for about 10% of global electricity use, with 1.6 billion air conditioners installed.

Air conditioning versus heating

Heating remains by far the biggest energy item in a French home. Next to it, home air conditioning weighs little:

• heating runs five to seven months a year, air conditioning a few weeks;
• heating draws much more power than a wall-mounted split;
• a building's insulation affects the heating bill far more than the cooling bill.

In Haussmann buildings with shared gas central heating, heating is a large part of the service charges. Adding air conditioning is, by comparison, a modest energy cost, as long as it is set sensibly.

Reversible air conditioning: one unit for two seasons

Reversible air conditioning (an air-to-air heat pump) cools in summer and heats in winter. Its coefficient of performance (COP) is generally between 3 and 4 in heating mode: for 1 kWh of electricity used it delivers 3 to 4 kWh of heat, where a standard electric heater delivers 1.

In Paris flats it often serves as top-up heating in spring and autumn, when the building's shared heating is not yet on or has just been switched off. To compare with a heat pump that feeds radiators, see our article on heat pumps in a Paris apartment.

Why set your air conditioning to 26 °C

The recommended setting

ADEME recommends setting air conditioning to 26 °C during the day: every degree lower increases consumption. At night a slightly higher setting is generally enough, because your metabolism slows while you sleep.

At 26 °C the cooling is real compared with an unconditioned Paris flat in a heatwave. The difference from 22 °C is barely noticeable after a few minutes, once your body adjusts, especially in light clothing.

Why a few degrees change everything

The bigger the gap between outside and the set temperature, the longer and harder the compressor runs:

• at 26 °C, it runs intermittently to hold a reasonable gap with outside;
• at 22 °C, it runs almost non-stop;
• at 20 °C, a setting still seen, the unit is permanently overworked: faster wear and a soaring bill.

Real savings depend on the flat's insulation, the unit's efficiency (SEER) and the outdoor temperature.

The maximum gap with outside

Do not go more than 5 to 7 °C below the outdoor temperature. Too big a gap causes:

• thermal shock every time you go in or out, uncomfortable and risky for vulnerable people (dizziness, feeling faint);
• condensation on cold surfaces, and a risk of mould in an over-cooled flat;
• higher consumption, as the unit strains to hold an unrealistic gap.

If it is 36 °C outside, 29 to 30 °C inside is more sensible, and more comfortable, than 22 °C.

Other settings that lower the bill

• Night mode (or quiet mode) gradually raises the set temperature during the night.
• Timers: switch off while you are out. For more than two hours, turn it off or set a timer. For a short outing, leave it at 28 °C instead: cooling a hot room from scratch costs more than holding it.
• Airflow direction: point it upwards, not at people. The cool air spreads better and you will not be tempted to lower the setting.
• Closed doors: cool only the rooms in use. The unit reaches the set temperature faster and cycles off more often.
• Sun protection: close shutters, blinds and curtains during the hottest hours, and air the flat at night.

Maintenance equals performance

A dirty unit uses more for less:

• clogged filters: the unit strains to draw air. Clean them every 2 to 4 weeks when in use; it is quick and easy;
• dirty coil: dust on the fins reduces heat exchange. A yearly professional clean is recommended;
• low refrigerant: a leak, even a small one, reduces cooling and makes the compressor run longer.

What to watch for and the servicing rules are covered in our article on the signs an air conditioner needs maintenance.

From luxury to a health need

The heatwaves of 2003, 2019 and 2023 showed the dangers of extreme heat, especially for older people, young children and people with chronic illness. Tropical nights, when the temperature stays above 20 °C, stop the body from recovering. In cities, the urban heat island makes these episodes worse. In Haussmann buildings, top floors under the zinc and flats facing south-west are the most exposed.

For some homes and some people, air conditioning has become a health matter, not just comfort.

The environmental impact of air conditioning

Electricity and refrigerants

Air conditioning uses electricity, and in France electricity is largely low-carbon. The other issue is refrigerants: if they leak, they are powerful greenhouse gases. Hence the value of recent units using lower-impact refrigerants such as R32, and of regular servicing to prevent leaks.

2050: restraint or runaway growth

ADEME has modelled two scenarios for home air conditioning in France by 2050:

• restraint: 6 TWh, with efficient units, moderate settings and more passive solutions (insulation, sun protection, natural ventilation);
• mass adoption without restraint: 27 TWh.

Globally, the IEA projects that cooling demand will triple by 2050, with the number of air conditioners rising from 1.6 to 5.6 billion.

What makes the difference: high-efficiency units, a 26 °C setting, regular servicing, and passive solutions first (shutters, blinds, solar film, night ventilation). In apartment buildings, shared insulation and sun protection reduce the need for everyone.

Frequently asked questions

Does air conditioning use more energy than heating?

No, and by a wide margin. According to ADEME, home air conditioning accounts for only about 1% of household energy use, while heating remains by far the largest item.

What temperature should I set my air conditioning to?

26 °C during the day, as recommended by ADEME, and higher at night. Keep no more than 5 to 7 °C below the outdoor temperature.

Should I switch the AC off when I leave the flat?

For more than two hours, yes. For a short outing, leave it at 28 °C rather than restarting it on a hot room.

Does air conditioning make climate change worse?

It uses electricity and contains refrigerants that are greenhouse gases if they leak. In France, where electricity is largely low-carbon, the main issue is choosing an efficient unit and a low-impact refrigerant, and servicing it to prevent leaks.

How can I reduce my air conditioning's energy use?

Set it to 26 °C, close shutters and curtains during the hottest hours, cool only occupied rooms, clean the filters regularly and have the unit serviced every year.

Well-set air conditioning is not an energy drain

Correctly sized, set to 26 °C and serviced, air conditioning stays a reasonable energy cost. Réseau Tubulure installs, services and repairs air conditioning in Paris (75) and the inner suburbs (92, 93, 94). Call +33 1 89 70 15 36, 7 days a week, 24 hours a day, or request a diagnosis. For a new unit, read our guide to air conditioning installation in Paris. Many of our plumbers speak English.

Sources:

• ADEME, "La climatisation : vers une utilisation raisonnée pour limiter l'impact sur l'environnement": https://www.ademe.fr/presse/communique-national/la-climatisation-vers-une-utilisation-raisonnee-pour-limiter-limpact-sur-lenvironnement/
• ADEME, Batizoom, share of air-conditioned homes: https://batizoom.ademe.fr/indicateurs/part-des-logements-climatises
• IEA, The Future of Cooling: https://www.iea.org/reports/the-future-of-cooling