Figure 12 shows a drop-in system performance comparison of R32 versus three HFO blends with GWP around 500
in the same system described above at those same four test conditions with only TXV and charge adjustments allowed. Plotting the relative capacity and EER of the alternatives versus R410A on the x- and y- axes respectively enables a quick visual comparison as typically a +5% capacity can be traded away for about +2% higher EER by downsizing compressor displacement for same capacity as shown by the diagonal line. The upper right quadrant is the first desired zone (both higher capacity and higher EER) and the upper left quadrant is a close second. As can be seen, R32 performs reasonably close on a drop-in basis without much compressor and system optimization. The three HFO blends are more spread to the upper left quadrant and having more significant drop in H/P performance compared to R32 except for HFO #1 which could be a close drop-in for R410A. These HFO blends are subject to more optimization changes in the future and the results could change.