One of the very first steps when it comes to diagnosing your home air conditioner, refrigerator, or even your vehicle’s air conditioner is understanding the temperature and the current pressure that your system is operating at. Having these facts along with the saturation point, the subcool, and the superheat numbers for the refrigerant you are working on are essential when it comes to really understanding what is going wrong with your system.
After a visual inspection the very next step for the most seasoned technicians is pulling out their gauges and checking the pressure and temperature. It just becomes second nature after enough calls. I have heard stories of rookie techs calling some of the pros on their team for help on a system that they’re stuck on. It doesn’t matter what the situation is. It doesn’t matter if you’re in Miami or in Fargo. It will never fail that one of the first questions the pros ask the rookie is what is your subcool and what is your superheat? Having and understanding these numbers is key to figuring out what to do next.
But, these numbers won’t do you any good if you don’t know what refrigerant you are dealing with and what the refrigerant’s boiling point is at each pressure level. This article aims at providing you with just that information.
R-1234ze Refrigerant Information
The refrigerant R-1234ze is part of a new generation of refrigerants under the HFO classification. HFO’s, or hydrofluoroolefins, are a new classification of refrigerants that aim to take the place of the commonly used HFCs. These HFC refrigerants have a VERY high Global Warming Potential, or GWP. The higher the GWP the more damage the refrigerant can do to Global Warming. Remember folks that refrigerants are Greenhouse Gases and can be many times more potent then the standard Carbon Dioxide. Having these very high GWP refrigerants was causing a significant impact on Climate Change.
R-1234ze was introduced as an alternative to the R-134a HFC refrigerant. R-134 has a GWP number of over fourteen-hundred. That means it is fourteen-hundred times worse then Carbon Dioxide when released into the atmosphere. To combat this the Honeywell corporation released R-1234ze under their Solstice Refrigerants brand name. This refrigerant has no Ozone Depletion Potential and has a GWP number of only seven.When comparing that to the fourteen-hundred we saw earlier you can really see the difference.
R-1234ze can be used in a variety of applications including supermarkets, water cooled chillers, commercial buildings, vending machines, refrigerators, heat pumps, and it can even be found in cascade systems. While it was meant to replace R-134a it can also be used in place of other refrigerants such as R-744 (Carbon Dioxide) and R-600a (Isobutane). The only major downside of this refrigerant is that it is rated as an A2L from ASHRAE. The A stands for non-toxic but that 2l rating signifies that this HFO refrigerant is slightly flammable. R-134a on the other hand had no chance of flame propagation. So, please be cognizant of the flammability risk when working with R-1234ze refrigerant.
If you are working with R-1234ze then you need to know the temperatures and pressures. Please check out the pressure chart below.
R-1234ze PT Chart
Temp (F) | Temp (C) | Pressure (PSIG) | Pressure (kPA) |
---|---|---|---|
-58 | -50 | -11.75 | -81 |
-54.4 | -48 | -11.31 | -78 |
-50.8 | -46 | -10.88 | -75 |
-47.2 | -44 | -10.44 | -72 |
-43.6 | -42 | -9.86 | -68 |
-40 | -40 | -9.43 | -65 |
-36.4 | -38 | -8.85 | -61 |
-32.8 | -36 | -8.12 | -56 |
-29.2 | -34 | -7.4 | -51 |
-25.6 | -32 | -6.67 | -46 |
-22 | -30 | -5.8 | -40 |
-18.4 | -28 | -4.93 | -34 |
-14.8 | -26 | -4.06 | -28 |
-11.2 | -24 | -3.05 | -21 |
-7.6 | -22 | -1.74 | -12 |
-4 | -20 | -0.73 | -5 |
-0.4 | -18 | 0.58 | 4 |
3.2 | -16 | 2.03 | 14 |
6.8 | -14 | 3.48 | 24 |
10.4 | -12 | 4.93 | 34 |
14 | -10 | 6.67 | 46 |
17.6 | -8 | 8.41 | 58 |
21.2 | -6 | 10.3 | 71 |
24.8 | -4 | 12.33 | 85 |
28.4 | -2 | 14.5 | 100 |
32 | 0 | 16.68 | 115 |
35.6 | 2 | 19.15 | 132 |
39.2 | 4 | 21.61 | 149 |
42.8 | 6 | 24.22 | 167 |
46.4 | 8 | 27.12 | 187 |
50 | 10 | 30.02 | 207 |
53.6 | 12 | 33.07 | 228 |
57.2 | 14 | 36.4 | 251 |
60.8 | 16 | 39.89 | 275 |
64.4 | 18 | 43.51 | 300 |
68 | 20 | 47.28 | 326 |
71.6 | 22 | 51.2 | 353 |
75.2 | 24 | 55.4 | 382 |
78.8 | 26 | 59.76 | 412 |
82.4 | 28 | 64.4 | 444 |
86 | 30 | 69.18 | 477 |
89.6 | 32 | 74.11 | 511 |
93.2 | 34 | 79.34 | 547 |
96.8 | 36 | 84.85 | 585 |
100.4 | 38 | 90.5 | 624 |
104 | 40 | 96.45 | 665 |
107.6 | 42 | 102.69 | 708 |
111.2 | 44 | 109.07 | 752 |
114.8 | 46 | 115.74 | 798 |
118.4 | 48 | 122.56 | 845 |
122 | 50 | 129.95 | 896 |
125.6 | 52 | 137.35 | 947 |
129.2 | 54 | 145.18 | 1001 |
132.8 | 56 | 153.31 | 1057 |
136.4 | 58 | 161.72 | 1115 |
140 | 60 | 170.42 | 1175 |