Condensation heat transfer and frictional pressure drop of R410A, R455A, R454C, and a newly proposed ternary low-GWP (Low-Global Warming Potential) refrigerant (R1234yf/R13I1/R32) were experimentally investigated in a horizontal smooth tube. The heat transfer results established R410A and R1234yf/R13I1/R32 as the upper and lower performance bounds, respectively, while the two low-GWP blends occupied an intermediate range. The hydraulic behavior showed a different ranking from the heat transfer performance, indicating that thermal advantage and pressure-drop reduction are controlled by different refrigerant properties. Among the three established correlations, Shah (2022) provided the best overall agreement and was selected as the basis for further development. The Bell–Ghaly mixture correction was modified by replacing the vapor quality weighting term with a Zivi-based void fraction and the uniform phase equilibrium slope with a local pointwise slope. The proposed correlation reduced the overall Mean Absolute Deviation (MAD) from 16.9% to 9.3% and Mean Relative Deviation (MRD) from +16.7% to +4.3% across all 150 data points compared to Shah (2022).
Fauzan et al. (2026) studied this question.