If you suspect a problem in the refrigerant system, inspect for the following conditions:
Perform the following hand-feel procedure to get a quick idea of whether the air conditioning (A/C) system has the proper charge of Refrigerant-134a. The air temperature must be above 21°C (70°F) for most models.
°C  | °F  | kPa  | psi  | °C  | °F  | kPa  | psi  | 
|---|---|---|---|---|---|---|---|
*All values rounded to 2 decimal places. EVAPORATOR RANGE: From -6.67 to +7.22°C (20-45°F), the temperatures represent the gas temperatures inside the coil and not on the coil surfaces. Add 1.67-5.56°C (3-10°F) to the temperature for coil and air-off temperatures. CONDENSER RANGE: From 43-71°C (110-160°F), temperatures are not ambient. Add 19.4-22.2°C (35-40°F) for proper heat transfer, then refer to the pressure chart. Example: 32°C (90°F) ambient temperature +22°C (40°F) = 54°C (130°F). Condenser temperature = 1 379 kPa (200 psi), based on 48.3 km/h (30 mph) airflow.  | |||||||
-8.89  | 16  | 105.70  | 15.33  | 37.78  | 100  | 856.84  | 124.27  | 
-7.78  | 18  | 114.87  | 16.66  | 38.89  | 102  | 886.56  | 128.58  | 
-6.67  | 20  | 124.32  | 18.03  | 40  | 104  | 916.35  | 132.98  | 
-5.56  | 22  | 134.11  | 19.45  | 41.11  | 106  | 947.92  | 137.48  | 
-4.44  | 24  | 144.24  | 20.92  | 42.22  | 108  | 979.64  | 142.08  | 
-3.33  | 26  | 154.65  | 22.43  | 43.33  | 110  | 1012.11  | 146.79  | 
-2.22  | 28  | 165.48  | 24  | 44.44  | 112  | 1045.21  | 151.59  | 
-1.11  | 30  | 176.65  | 25.62  | 45.56  | 114  | 1079.14  | 156.51  | 
0  | 32  | 188.16  | 27.29  | 46.67  | 116  | 1113.75  | 161.53  | 
1.11  | 34  | 200.02  | 29.01  | 47.78  | 118  | 1149.12  | 166.66  | 
2.22  | 36  | 212.30  | 30.79  | 48.89  | 120  | 1185.18  | 171.89  | 
3.33  | 38  | 224.98  | 32.63  | 50  | 122  | 1222.07  | 177.24  | 
4.44  | 40  | 238.08  | 34.53  | 51.11  | 124  | 1259.72  | 182.70  | 
7.22  | 45  | 272.49  | 39.52  | 52.22  | 126  | 1298.12  | 188.27  | 
10  | 50  | 309.58  | 44.9  | 53.33  | 128  | 1337.35  | 193.96  | 
12.77  | 55  | 349.51  | 50.69  | 54.44  | 130  | 1377.35  | 199.76  | 
15.56  | 60  | 392.33  | 56.9  | 57.22  | 135  | 1480.91  | 214.78  | 
18.33  | 65  | 438.18  | 63.55  | 60  | 140  | 1589.57  | 230.54  | 
21.11  | 70  | 487.27  | 70.67  | 62.78  | 145  | 1703.62  | 247.08  | 
23.89  | 75  | 539.67  | 78.27  | 65.56  | 150  | 1823.04  | 264.4  | 
26.67  | 80  | 609.38  | 88.38  | 68.33  | 155  | 1948.04  | 272.53  | 
29.44  | 85  | 655.09  | 95.01  | 71.11  | 160  | 2078.77  | 301.49  | 
32.22  | 90  | 718.39  | 104.19  | 73.89  | 165  | 2215.29  | 321.29  | 
35  | 95  | 785.61  | 113.94  | 76.67  | 170  | 2357.81  | 341.96  |