Figure 2. Alternative refrigerants used to calculate the Low-GWP and Medium-GWP scenarios. The Low-GWP scenario assumes equipment using high-GWP refrigerants is replaced at end-of-life with equipment using alternative refrigerants with GWP<5. The medium-GWP calculations assume GWP<800 (100-yr basis) and GWP<2,700 (20-yr basis) alternatives in applications where low-GWP replacements are currently less common (commercial refrigeration, transport refrigeration, stationary air conditioning) and assumes low-GWP replacements for the remaining applications where they are more developed technologies (residential refrigeration, industrial refrigeration, mobile air conditioning). The alternative refrigerants in the table are used for effectiveness and/or cost calculations. Sources: Purohit & Höglund-Isaksson (2017); Sustainable Purchasing Leadership Council Climate Friendly Refrigerant Action Team (2021); UNEP (2023); UNFCCC (2023); U.S. Environmental Protection Agency (2011).
| Application |
Scenario 1: Low-GWP only (low GWP: < 5, 100-year basis) |
Scenario 2: Medium-GWP when low-GWP alternatives are less common, otherwise low-GWP (medium GWP: < 800, 100-year basis) |
|---|---|---|
| Residential refrigeration | Isobutane | |
| Commercial refrigeration | Propane, CO₂ | Medium-GWP HFC and HFO blends |
| Industrial refrigeration | Ammonia, CO₂, propane | |
| Transport refrigeration | Propane, propene, ammonia, CO₂, low-GWP HFOs |
Medium-GWP HFC and HFO blends |
| Mobile AC | CO₂, low-GWP HFOs | |
| Stationary AC | Propane, CO₂, ammonia, low-GWP HFOs |
Medium-GWP HFC and HFO blends |