1 calculating subcooling, Example, Calculating subcooling – Liebert Challenger ITR User Manual
Page 63: Table 33
R407C Refrigerant
57
8.1
Calculating Subcooling
Example
Measure the liquid pressure (e.g., 200 psig). Find the liquid saturation temperature at that pressure
on Table 33 (e.g., 93°F). Measure the temperature of the liquid line (e.g., 90°F). Subtract the actual
temperature from the liquid saturation temperature to obtain the subcooling (e.g., 93 – 90 = 3°F). If
the actual temperature is greater than the liquid saturation temperature, then there is no subcooling,
and the fluid may be a mixture of liquid and vapor.
Why There Are Two R407C Temperature and Pressure Tables
R407C is a blend of refrigerants that exhibits a temperature “glide” of approximately 8 to 12°F
(4 to 7°C. This “glide” is the difference between the liquid and vapor saturation temperatures at a
given pressure. Use the correct table for the saturation temperature you need. Table 32 is for super-
heat or operating controls. Table 33 is for subcooling only.
Table 33
R407C pressure/temperature chart for subcooling only (liquid measurements)
Temperature
Pressure Gauge
Temperature
Pressure Gauge
Temperature
Pressure Gauge
°F
°C
Psig
kPa
°F
°C
Psig
kPa
°F
°C
Psig
kPa
36.0
2.2
73
500
59.0
15.0
114
786
94.0
34.4
203
1402
37.0
2.8
74
511
60.0
15.6
116
801
96.0
35.6
209
1444
38.0
3.3
76
522
61.0
16.1
118
815
98.0
36.7
216
1488
39.0
3.9
77
533
62.0
16.7
120
830
100.0
37.8
222
1532
40.0
4.4
79
544
63.0
17.2
123
845
102.0
38.9
229
1578
41.0
5.0
81
556
64.0
17.8
125
860
104.0
40.0
236
1624
42.0
5.6
82
567
65.0
18.3
127
875
106.0
41.1
242
1671
43.0
6.1
84
579
66.0
18.9
129
891
108.0
42.2
249
1720
44.0
6.7
86
591
67.0
19.4
131
906
110.0
43.3
257
1769
45.0
7.2
87
602
68.0
20.0
134
922
112.0
44.4
264
1819
46.0
7.8
89
615
69.0
20.6
136
938
114.0
45.6
271
1870
47.0
8.3
91
627
70.0
21.1
138
954
116.0
46.7
279
1922
48.0
8.9
93
639
72.0
22.2
143
987
118.0
47.8
287
1975
49.0
9.4
95
652
74.0
23.3
148
1021
120.0
48.9
294
2029
50.0
10.0
96
664
76.0
24.4
153
1055
122.0
50.0
302
2085
51.0
10.6
98
677
78.0
25.6
158
1090
124.0
51.1
310
2141
52.0
11.1
100
690
80.0
26.7
163
1126
126.0
52.2
319
2198
53.0
11.7
102
704
82.0
27.8
169
1163
128.0
53.3
327
2256
54.0
12.2
104
717
84.0
28.9
174
1201
130.0
54.4
336
2315
55.0
12.8
106
730
86.0
30.0
180
1239
132.0
55.6
345
2376
56.0
13.3
108
744
88.0
31.1
185
1279
134.0
56.7
354
2437
57.0
13.9
110
758
90.0
32.2
191
1319
136.0
57.8
363
2500
58.0
14.4
112
772
92.0
33.3
197
1360
138.0
58.9
372
2563
-
-
-
-
-
-
-
-
140.0
60.0
381
2628
NOTE
Use this table for subcooling calculation ONLY. See Table 32 for superheat or control
adjustment.