Impact of a Leak (DX Cycle)
Impact of accidental refrigerant leak in DX (direct expansion) Cycle on
Safety, Health & Environment. (A1 class R410A & A2L class R32)
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 (a controlled substance) accidental leak or release, there are two issues must be considered, Saftey & Environmental effect (2-TEWI & 3-ODP). These issues are described in two International Standards, which identifies the risks associated with refrigerant leaks or released. 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 🔥) and A3 class (highly flammable & explosive 🔥💥). Toxicity is measured as, (B1 low, B2 medium, B3 high). GWP (Global Warming Potential)
- Safety (flammability & Toxicity) of installers, service engineers, operators and USERS (accidental release)
- TEWI* (Total Environmental Warming Impact) Includes energy consumption (operational & accidental release)
- ODP (Ozone Depletion Potential) CFC & HCFC (accidental release)
i) 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.
ii) *Total Environmental Warming Impact (TEWI) = Total greenhouse gas emissions (CO2) over a specific product life cycle, including:
a) the effects of refrigerant inadvertently released to the atmosphere from accidents, servicing, and leakage; b) the efficiency of the cooling equipment (due to the emission of CO2 from burning fuel to power the system); and c) the emission of CO2 from burning fuel (electricity) to operate the system. (read more)
iii) Ozone Depletion Potential (ODP) in the event of release into the atmosphere. (applies to CFC, HCFC not HFC, HFO or HC)