GWP & ODP
What GWP and ODP mean, why they matter, and how to use them without oversimplifying refrigerant impact.
Environmental metrics are useful, but they are not the full story. Two of the most common terms you will see in refrigerant discussions are GWP (Global Warming Potential) and ODP (Ozone Depletion Potential).
Quick definitions
GWP (100-year) A relative measure of how much heat a greenhouse gas traps over a chosen time horizon (often 100 years), compared to CO2. Published GWP values can vary by time horizon (20-year vs 100-year) and by the assessment/reporting standard used, so treat them as a standardized reference rather than a single "true" constant.
ODP A relative measure of a chemical's potential to deplete stratospheric ozone, compared to a reference substance. It is most relevant for substances like CFCs and HCFCs (e.g., legacy refrigerants).
How to interpret these metrics
- Use GWP/ODP as screening metrics, not as the sole decision criterion.
- Real-world impact depends on system design, leakage rate, service practices, end-of-life recovery, and the electricity mix driving the equipment.
- Always check local regulations and safety codes -- policy constraints can dominate technical preferences.
Where FluidTool helps
FluidTool focuses on thermodynamic calculations (properties, phase behavior, critical point, and charts). You can use it to compare how candidate fluids behave across a range of pressures and temperatures.