The HFO blends need to offer more compelling advantages over R32 due to their currently higher cost. They have same A2L flammability as R32. To sustain efficiency, their GWP is constrained to around 500, not much lower than R32 when charge is factored in. No visible advantages over R32 have been seen in these early drop-in system test results. More system data from the AHRI LGWP AREP program are needed to see further trends. On an LCCP basis, the HFO blends are comparable to R32, but their use may be limited initially until their cost position becomes clearer. R1234ze is reportedly a fraction of the cost of R1234yf, so R1234ze blends may offer potential to be closer to R410A cost and merit further investigation.