Impact of a Leak (DX Cycle)

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Accidential refrigerant leak

Mandatory measures


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About refrigerants?

Refrigerants (CFC, HCFC, HFC, HC & HFO’s, natural or man-made) are controlled substances due to high pressures 100 - 450 psi, and extreme temperatures -50°C to 140°C, flammability & toxicity as classified by ISO817 & ASHRAE34. They must only be handled by qualified & certified engineers to C&G 2079-11 for (A1 class non-flammable), plus C&G 6187-21 for (A2/A2L/A3 class flammable/explosive). (about C&G)


Refrigerant circulates around (closed circuit) the DX cycle to perform energy transfer from inside to outside (cooling) or from outside to inside (Heating or Heat Pump). The refrigerant MUST NOT leak, as the system will shut down by built-in controls

If there is a refrigerant accidental leak or release, there are two issues must be considered, Saftey & Environmental effect (TEWI/GWP & ODP). These issues are described in two International Standards, which identifies the risks associated with refrigerant leaks or release. ISO817 & ASHRAE 34. These standards classifies refrigerants in terms of Flammability, Toxicity & GWP.

Flammibility is measured as, A1 class (non-flammable  ), A2/A2L class (flammable šŸ”„) and A3 class (highly flammable & explosive šŸ”„šŸ’„). Toxicity is measured as, (B1 low, B2 medium, B3 high). GWP (Global Warming Potential) 

 Accidental refrigerant LEAK has THREE consequences that must be taken into account:

  1. Safety (flammability & Toxicity) A of installers, service engineers, operators and USERS (accidental release)
  2. TEWI* (Total Environmental Warming Impact) B Includes energy consumption (operational & accidental release)
  3. ODP (Ozone Depletion Potential) C CFC & HCFC (accidental release) 

A) Flammability being A1 Non-Flammable, A2/A2L Flammable or A3 Extremly Flammable & Explosive.
   Toxicity (mainly displacement of Oxygen in an occupied space) being B1 Low, B2 Medium and B3 High.

B) *Total Environmental Warming Impact (TEWI) = Total greenhouse gas emissions (CO2) over a specific product life cycle, including:
1) the effects of refrigerant inadvertently released to the atmosphere from accidents, servicing, and leakage; 2) the efficiency of the equipment (due to CO2 emission from burning fuel to generate electricity to power the system). (read more)

C) Ozone Depletion Potential (ODP) in the event of release into the atmosphere. (applies to CFC, HCFC not HFC, HFO or HC)

UK Government Study in 2018 regarding flammable refrigerants

Gov Study: The impact of high GWP (above 750) A1 class  non-flammables refrigerants (e.g. R410A) in Heat Pumps, concluded that the carbon benefit of displacing fossil fuels was around 17 times higher than the impact of refrigerant leaks. without the risks, cost and uncertainty of A2L class šŸ”„ flammable refrigerants future (e.g. R32)

"Having low GWP but being A2L class šŸ”„ flammable (like R32 as a single component) defeats the objective reason of protecting the environment 
IF leakedwhile creating a fire risk!!"


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*TEWI : These industries are now being affected by scientific investigations of greenhouse warming and questions about the effects of refrigerants on global warming. Automobile air-conditioning has three separate impacts on global warming; 1) the effects of refrigerant inadvertently released to the atmosphere from accidents, servicing, and leakage; 2) the efficiency of the cooling equipment (due to the emission of CO2 from burning fuel to power the system); and 3) the emission of CO2 from burning fuel to transport the system. The Total Equivalent Warming Impact (TEWI) is an index that should be used to compare the global warming effects of alternative air-conditioning systems because it includes these contributions from the refrigerant, cooling efficiency, and weight.





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