Let’s take a look at the R134a pressure chart also know as Ac pressure chart. In this article, you will get to know how can you measure the AC pressure using the gauges. You can compare the value for your vehicle using the car ac pressure charts below.
| R-134a TEMPERATURE PRESSURE CHART (Tabla de Temperaturas y Lecturas) |
||
|---|---|---|
| Ambient Temperature °F / °C (Temperatura Ambiental) | Low-Pressure Gauge (Puerto de Servicio del Lado de Baja Presion) | High-Pressure Gauge (Puerto de Servicio del Lado de Lado de Alta Presion) |
| 65°F (18°C) | 25-35 psi / 172-241 kPa | 135-155 psi / 931-1069 kPa |
| 70°F (21°C) | 35-40 psi / 241-276 kPa | 145-160 psi / 1000-1103 kPa |
| 75°F (24°C) | 35-40 psi / 241-310 kPa | 150-170 psi / 1034-1172 kPa |
| 80°F (27°C) | 40-50 psi / 276-345 kPa | 175-210 psi / 1207-1448 kPa |
| 85°F (29°C) | 45-55 psi / 310-379 kPa | 225-250 psi / 1551-1724 kPa |
| 90°F (32°C) | 45-55 psi / 310-379 kPa | 250-270 psi / 1724-1862 kPa |
| 95°F (35°C) | 50-55 psi / 345-379 kPa | 275-300 psi / 1896-2068 kPa |
| 100°F (38°C) | 50-55 psi / 345-379 kPa | 315-325 psi / 2172-2241 kPa |
| 105°F (41°C) | 50-55 psi / 345-379 kPa | 330-335 psi / 2275-2310 kPa |
| 110°F (43°C) | 50-55 psi / 345-379 kPa | 340-345 psi / 2344-2379 kPa |
| Ambient temp is the outside atmospheric temperature. | ||
Table of Contents
How to Read an R134a low Side Pressure Chart
If you or your staff do not understand the gauges, you can not understand the air conditioning and R134a chart. You can learn to read the gauges with simple methods. First of all, you have to consider the following facts.
- Ambient Temperature
- Compressor Pressure
Ambient Temperature
Average air temperature or another environment near the equipment. Note In the process of measuring the ambient temperature, the measuring device (probe) should be shielded from drafts and heated by radiation.
In the case of Car AC, on a cold day when AC is turned off, pressure will be low. On a hot day, when AC is turned on, pressure will be high. You can see the demonstration of this concept in the image below.
Before measuureing the Ac pressure using the gauge, you must know that what are the normal reading for the gauge.
Here are the details in this chart.
According to the above chart, you can measure the ambient temperature. As the ambient temperature rises the red gauge also increases 40psi up to 225psi.
What is R-134A?
R134a refrigerant is a hydrofluorocarbon compound (NHS) with thermodynamic properties comparable to those of chlorofluorocarbon (Rl2.R134a refrigerant has zero ozone-depleting potential (ODP)) and is ubiquitous with the best refrigerant R12. R134a is the ideal refrigerant for working at high boiling and condensation conditions. R134a is a non-competitive refrigerant that has zero temperature “slip.” Always use polyester oil when working with R134a.
R134A REFRIGERANT CHARACTERISTICS
Refrigerant r134a (tetrafluorothane) is a odorless substance or color. It is considered the safest compound from the point of view of ecology, as it does not contain bromine and chlorine. Bromo-containing and chlorine-containing freons negatively affect the composition of the atmosphere, destroy the ozone layer. The second positive quality, which is due to the widespread use of this refrigerant – non-toxicity.
It was designed as a replacement for the r12 refrigerant.
The refrigerant r 134a is difficult to ignite, but can break down into toxic products when exposed to an open flame. The system should be completely airtight, because when the refrigerant and the air are connected, combustible mixtures are formed.
It is used in combination with polyester lubricant. Mixing freon r134a with other refrigerants is not recommended.
R-134A Refrigerant Pressure Temperature Chart
| PSIG | R-134A Temperature | PSIG | R-134A Temperature |
|---|---|---|---|
| (10) | -31 | 74 | 72 |
| (8) | -27 | 76 | 74 |
| (6) | -24 | 78 | 75 |
| (4) | -21 | 80 | 76 |
| (2) | -18 | 82 | 77 |
| 0 | -15 | 84 | 78 |
| 2 | -10 | 86 | 81 |
| 4 | -5 | 88 | 83 |
| 6 | -1 | 90 | 82 |
| 8 | 3 | 92 | 83 |
| 10 | 7 | 94 | 84 |
| 12 | 10 | 96 | 85 |
| 14 | 13 | 98 | 86 |
| 16 | 16 | 100 | 87 |
| 18 | 19 | 105 | 90 |
| 20 | 22 | 110 | 93 |
| 22 | 25 | 115 | 96 |
| 24 | 27 | 120 | 98 |
| 26 | 30 | 125 | 100 |
| 28 | 32 | 130 | 102 |
| 30 | 35 | 135 | 105 |
| 32 | 37 | 140 | 107 |
| 34 | 39 | 145 | 109 |
| 36 | 41 | 150 | 112 |
| 38 | 43 | 155 | 114 |
| 40 | 45 | 160 | 116 |
| 42 | 47 | 165 | 118 |
| 44 | 49 | 170 | 120 |
| 46 | 51 | 175 | 121 |
| 48 | 52 | 180 | 123 |
| 50 | 54 | 185 | 125 |
| 52 | 56 | 190 | 127 |
| 56 | 58 | 195 | 129 |
| 58 | 60 | 200 | 131 |
| 60 | 62 | 210 | 134 |
| 62 | 64 | 220 | 137 |
| 64 | 65 | 230 | 141 |
| 66 | 66 | 240 | 143 |
| 68 | 68 | 250 | 147 |
| 70 | 69 | 260 | 149 |
| 72 | 71 | 270 | 152 |
Conclusion
R 134a pressure chart is essential to understand especially for a technician. In this article, you can learn the basic concept behind that and you can also learn how to read the ambient temperature using the gauges. You can compare your vehicle numbers with the charts in this article.
If you still have any questions regarding ac pressure chart, you can ask in the comment section and we will be more than happy to help you.