R1234yf was designed to closely match the performance of R134a while offering a much lower environmental impact. Here’s how it compares:
| Property | R1234yf | R134a |
|---|---|---|
| Critical Temperature | 94.7°C (202.5°F) | 101.1°C (214°F) |
| Critical Pressure | 3.38 MPa (490 psi) | 4.06 MPa (589 psi) |
| Volumetric Cooling Capacity | ~5-10% lower than R134a | Higher |
| Coefficient of Performance (COP) | Slightly lower (~5-10%) | Better |
| Pressure-Temperature Relationship | Similar to R134a, but slightly higher pressures at high temps | More stable at high loads |
Cooling Efficiency: R1234yf provides similar but slightly lower cooling capacity than R134a, requiring system adjustments (e.g., larger heat exchangers or higher compressor speeds in some cases).
Pressure Behavior: Operates at slightly lower pressures than R134a under normal conditions but may approach similar levels at high ambient temperatures.
Compatibility with Lubricants: Typically uses POE (Polyolester) oils, similar to R134a systems, but requires strict moisture control.
R1234yf is classified as A2L (low flammability) under ASHRAE Standard 34, meaning it burns very slowly and requires a high ignition energy.
| Risk Factor | Details | Safety Measures |
|---|---|---|
| Mild Flammability | Can ignite at >405°C (761°F) with a flame speed of <1.5 cm/s (much slower than hydrocarbons like propane). | - Avoid open flames/sparks during servicing. - Use leak detectors before repairs. |
| Toxicity | Low toxicity (similar to R134a), but decomposition products (e.g., HF gas) are hazardous. | - Work in ventilated areas. - Use PPE (gloves, goggles). |
| High Pressure Risks | Like R134a, improper handling can cause pressure-related injuries. | - Follow proper recovery/recharge procedures. - Use certified equipment. |
