How to determine the carbon footprint of an air conditioning system

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More frequent, more extreme, and longer-lasting heat waves have pushed people to invest in air conditioning systems. Whilst they greatly increase one’s comfort, air conditioning systems produce a large amount of greenhouse gasses, which are harmful to the environment.

This article will explain how to determine the carbon emissions caused by your air conditioning systems.

The different types of air conditioning

Not all air conditioning systems are equal, as some produce much more carbon emissions than others. There are various solutions to cool a building down, be it for professional or domestic use.

Portable air conditioners

Small and easy to carry, portable air conditioners are the easiest to use in flats. These units are also one of the cheapest options on the market. They are, however, one of the least energy-efficient models available to consumers.

Reversible heat pumps

In households, reversible heat pumps are quite common, used to heat buildings during the winter. When summer arrives, their mechanism can be reversed to provide cool air.

Cold units

These units are usually used to cool down big buildings.

“Rooftop” systems

“Rooftop” systems are units installed on the roofs of buildings to provide air conditioning. Such a system is suited to cool down big spaces, like supermarkets or warehouses. They are quite simple to install.

Various points of CO2 emissions linked to air conditioning

The carbon emissions linked to air conditioning are caused by the consumption of electricityleaks in the system, and the pollution linked to disposing of the system at the end of its life. It’s important to identify each type of emission in order to determine the carbon footprint of your air conditioning system.

Electricity consumption

Electricity consumption is a major source of carbon emissions. An air conditioning system needs a lot of energy to work and the production of such energy can release a large amount of greenhouse gasses.

When determining carbon emissions, energy production for an air conditioning unit is included in the building’s total electricity consumption, or in a building’s energy consumption per square metre.

Fugitive emissions (gas leaks)

Most air conditioning units rely on refrigerants that cool down surrounding air. These gases pollute a lot and heat the environment when used in the open.

Fugitive emissions are the emissions linked to gas leaks. These leaks happen systematically in air conditioning units, pointing to the importance of taking proper care of such units.

In general, gas leaks are responsible for twice as many greenhouse gas emissions as those linked to the unit’s electricity consumption.

Disposing of an old air conditioning system

When an air conditioning system is destroyed, it releases carbon emissions. These emissions are never calculated beforehand, however, so can be ignored when calculating the emissions linked to an air conditioning unit.

The most important, then, is to evaluate the fugitive emissions linked to the release of refrigerating gases.

How to calculate fugitive emissions linked to air conditioning within the tertiary sector

In accordance with many laws, companies have to determine their carbon footprints. They thus have to evaluate the CO2 emissions linked to their air conditioning systems.

Carbon experts like Carbometrix can help companies with calculating emissions, which can be difficult. For your information, however, we have separated the calculation process into three steps :

Determine the intensity of air conditioning

Some companies are informed about their air conditioning systems, knowing the intensity and type of unit used.

On the other hand, most companies don’t have access to this information. They will have to make estimations based on the sector’s industry standards.

Most air conditioning systems used for companies are air-to-air units. Such a unit extracts calories from the surrounding air to cool it down. In order to do this, a refrigerant is continuously condensed and evaporated to cool the air.

To determine the intensity of an air conditioning unit, one has to consider the area that is cooled. On average, 100W is consumed per square metre cooled. Contacting a specialist, however, can give you a more precise calculation.

Evaluate gas leaks

The second step consists in evaluating gas leaks caused by air conditioning. If these leaks are unavoidable, it is best to regularly review the unit in order to avoid excessive leaks.

Greenhouse Gas Protocol has tools to evaluate gas leaks. They offer guidelines specific to air conditioning-related fugitive emissions.

Take into account which gas is used

It is essential to evaluate which gas is used for air conditioning, as the amount of carbon emissions differs according to the gas used.

It’s often difficult to determine which gas is used. The most commonly used gas, however, is R410A, which emits 1920 Kg per Kg used.

With all the variables that come into play when calculating greenhouse gas emissions, it is recommended that you contact a professional, like Carbometrix, to come up with the most reliable estimations.

Fugitive emissions vs electricity consumption

The weight of fugitive emissions in the total emissions differs depending on the type of air conditioning unit.

A portable air conditioner’s emissions, for example, are mostly caused by energy consumption. On the other hand, packaged air conditioners, most commonly used in companies, have emissions linked to both gas leaks and electricity consumption. For these units, it will be imperative to take emissions linked to leaks into account.

The SEER (Seasonal Efficiency Energy Ratio) rating helps determine the efficiency of an air conditioning unit. The rating is calculated by dividing the cooling output of a unit during summer by the energy this unit consumes during that same period.

Although this rating is helpful in determining the energy consumption of a unit, it does not show the total ecological impact of an air conditioner.

How to optimise air conditioning within a company

Air conditioning remains essential in certain offices during heat waves, but steps should be put in place to optimise its use and pollute less.

On a bigger scale, it means properly insulating buildings to keep the heat out in summer.

A company has several options:

  • Use less air conditioning: many companies tend to use air conditioning too much, which consumes a lot of energy and is very expensive for the company. For example, it takes twice as much energy to cool a room to 22℃, rather than keeping it at 27℃.

  • Maintain your air conditioning system: since gas leaks represent a large part of total emissions, it is best to regularly identify the biggest leaks.

  • Carefully consider the system you will use beforehand: choose your system according to the needs of your company, as this will save you money and pollute less during the hottest months.

Find help to understand the emissions caused by air conditioning

Air conditioning should always be taken into account when calculating a carbon footprint.

Fugitive emissions are scope 1 emissions, whilst emissions linked to energy consumption are scope 2 emissions.

When determining a carbon footprint, however, all other scope 1, 2, and 3 emissions should be taken into account.


Indeed, you need a total analysis of your carbon footprint to determine if your company needs to invest in a new air conditioning system.

The most urgent steps to be taken will vary depending on the part your air conditioning has on your total carbon footprint.

Contact Carbometrix to precisely calculate your carbon footprint, including the environmental impact of your air conditioning system, and determine the steps you should undertake.

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