Refrigerants: the hidden Scope 1 in your air conditioning

In the UAE summer, air conditioning takes a large share of the electricity generated, as Dubai Electricity and Water Authority (DEWA) points out. That electricity is Scope 2. But the air conditioner also contains a gas, and when that gas leaks it is Scope 1. Most companies never think about it, because nothing is burning and nothing is visible.

Where the gas is and how it escapes

An air conditioner moves heat using a sealed circuit filled with refrigerant gas. In a healthy system the gas stays inside for years. Joints, valves and pipes can loosen or corrode, and the gas slowly escapes. A New Zealand government guide to measuring emissions says that greenhouse gas emissions from hydrofluorocarbons (HFCs) are associated with unintentional leaks and spills from refrigeration units.

You cannot see or smell most of these leaks. You find out when a technician arrives because the unit no longer cools, and tops up the gas. That top-up is the number you need.

What global warming potential means

Gases trap heat to different degrees. Global warming potential (GWP) compares them. The GWP of a gas tells you how much warming one kilogram of it causes over a set period, compared with one kilogram of carbon dioxide (CO2). The values below use a 100-year period. CO2 is the reference, so its GWP is 1.

The table shows 100-year values from the Intergovernmental Panel on Climate Change (IPCC). The Fifth Assessment Report (AR5) values come from Table 8.A.1 of the IPCC working group 1 report. The Sixth Assessment Report (AR6) values are as listed in the GHG Protocol table of GWP values, which cites the IPCC.

Read the HFC-134a row. One kilogram of that gas warms the planet as much as 1,300 kilograms of CO2 over 100 years, on the AR5 basis. This is why a small top-up matters. The IPCC table also lists HFC-1234yf, a newer gas, with a value below 1.

The formula

The top-up equals the loss because of a simple assumption: the system was full before it leaked and is full again after the technician recharges it. The New Zealand guide treats top-ups as the preferred basis for estimating leakage and gives an example. A 6 kg top-up of HFC-134a at a GWP of 1,300 gives 6 x 1,300 = 7,800 kg CO2e, which is 7.8 tonnes.

Blends such as R-410A

Many air conditioners use a blend of gases. R-410A is a 50/50 blend by mass of R-32 and R-125. The same guide explains that if you know the composition, you can calculate the GWP of a blend from the share of each gas.

On the AR5 values: 0.5 x 677 + 0.5 x 3,170 = 338.5 + 1,585 = 1,923.5. This matches the figure listed in the guide. On the AR6 values: 0.5 x 771 + 0.5 x 3,740 = 385.5 + 1,870 = 2,255.5. A 5 kg top-up of R-410A therefore gives 5 x 1,923.5 = 9,617.5 kg CO2e on AR5, or about 9.6 tonnes.

What to ask your technician for

The number only exists if somebody writes it down. Ask every technician to put three things on the invoice.

• The gas type, for example R-410A, R-32 or R-134a. Ask the technician to read it from the unit's label.
• The kilograms added, not just the words recharged or topped up.
• Which unit or site the work was done on, so you can total the year by location.

Add up all visits in the calendar year. The report asks for the kilograms of each gas added during the year. If an old invoice gives no weight, ask the contractor to confirm it in writing, and mark it as an estimate until they do.

Cut the leak, not just the paperwork

• If a unit needs a top-up more than once, ask the technician to find and fix the leak instead of recharging again.
• Keep a one-line log per unit: date, gas, kilograms, reason.
• When you replace a unit, ask which gas the new one uses and write the answer in your equipment list.

DecarbOS Intelligence prepares Scope 1, 2 and 3 emissions reports and physical climate reports. It does no consulting.

General information, not legal advice.