R-1234yf and R-290
(propane) have a near zero GWP, but they have flammability classifications of 2L and 3, respectively.
With multiple breakthroughs in energy efficiency, safety, noise reduction and material control, Midea R-290
product had obtained over 200 domestic and international patents before it was finally awarded the Blue Angel Certification.
 Zhang, W., Yang, Z., Li, J., Ren, C.-x., Lv, D., Wang, J., Zhang, X., and Wu, W., 2013, "Research on the flammability hazards of an air conditioner using refrigerant R-290
," International Journal of Refrigeration, 36(5), pp.
The R-1270 behavior is similar to that of R-290
but with a more rapidly propagating flame in the tube (linear speed up to 0.89 m/s [35 in./s]).
Baseline and Alternative Refrigerant Data ASHRAE GWP, (a) GWP, (a) Refrigerant Safety AR4 AR5 Class (c) R-22 unit R-22 (Baseline) (a) A1 1810 1760 N-20B (b) A1 988 904 DR-3 (b) A2L 148 146 ARM-20B (b) A2L 251 251 L-20A (R-444B) (b) A2L 295 295 DR-93 (b) A1 1258 1153 Propane (R-290
) A3 3 3 R-410A unit R-410A (Baseline) (a) A1 2088 1924 ARM-71A (b) A2L 460 461 R-32 (a) A2L 675 677 DR-55 (b) A2L 698 676 L41-2 (R-447A) (b) A2L 583 572 HPR-2A (b) A2L 600 593 (a) Sources: IPCC (Intergovernmental Panel on Climate Change) Assessment Report AR4 (IPCC 2007), IPCC AR5 (IPCC 2013) (b) GWP values for refrigerant blends not included in IPCC reports are calculated as a weighted average using manufacturer-supplied compositions.
(3) REFRIGERANT GLOBAL WARMING OZONE DEPLETION ASHRAE SAFETY POTENTIAL (GWP) POTENTIAL (ODP) CLASSIFICATION R-22 1,810 0.040 A1 R-404A 3,922 0 A1 R-507A 3,985 0 A1 R-407A 2,107 0 A1 R-410A 2,088 0 A1 R-407F 1,825 0 A1 R-1270 3 0 A3 R-290
(Propane) 3 0 A3 R-744 (Carbon 1 0 A1 Dioxide) R-717 (Ammonia) <1 0 B2L
Condensation heat transfer and pressure drop characteristics of R-290
(propane), R-600 (butane), and a mixture of R-290/R-600 in the serpentine small-tube bank.
List of Refrigerants from Brown (2007) R-11 R-41 R-134a R-152a R-236fa R-600 R-12 R-123 R-141b R-170 R-245ca R-600a R-22 R-124 R-142b R-218 R-245fa R-1270 R-32 R-125 R-143a R-227ea R-290
R-C318 Table A2.
can be expected to have a satisfactory COP, but lose about 15% capacity compared to R-22.
In light of the F-gas regulation, Emerson says r-290
is an attractive alternative to commonly used refrigerants.
The results of R-1270 (C[H.sub.3]CH=C[H.sub.2]), R-290
([C.sub.3]H8), R-152a, R-143a, and R-32 by Jabbour (2004) with a 40 mm (1.6 in.) diameter tube are also shown in this figure.