Classic HVPA & HVPSA M&S 8.09-1
15700 - 16
HVAC Equipment
Subcooling Calculation
1. Measure the liquid pressure at the liquid line service valve.
2. Convert the liquid line pressure to saturated temperature. See tables below.
3. Measure the liquid line temperature at the liquid line service valve.
4. Compare the liquid line temperature to the saturated temperature.
5. The difference between saturated temperature and liquid line temperature is the
subcooling. Subcooling normal range 12° to 20°.
Superheat Calculation
1. Measure the suction pressure at the suction line service valve.
2. Convert the suction line pressure to saturated temperature. See tables below.
3. Measure the suction line temperature approximately 6” to 8” from the compressor.
4. Compare the suction line temperature to the saturated temperature.
5. The difference between saturated temperature and suction line temperature is the
superheat. Superheat normal range 12° to 18°
Temperature Pressure Chart
Temp.
(°F)
R-22
PSIG
R-410A
PSIG
Temp.
(°F)
R-22
PSIG
R-410A
PSIG
Temp.
(°F)
R-22
PSIG
R-410A
PSIG
-40
0.5
11.0
25
48.7
86.0
90
168.4
273.0
-35
2.6
14.2
30
54.9
95.5
95
181.8
294.1
-30
4.9
17.8
35
61.5
105.7
100
195.9
316.4
-25
7.4
21.8
40
68.5
116.6
105
210.7
339.9
-20
10.1
26.1
45
76.0
128.3
110
226.3
364.6
-15
13.2
30.8
50
84.0
140.8
115
242.7
390.5
-10
16.5
35.9
55
92.5
154.1
120
259.9
417.7
-5
20.0
41.5
60
101.6
168.2
125
277.9
446.3
0
23.9
47.5
65
111.2
183.2
130
296.8
476.3
5
28.2
54.1
70
121.4
199.2
135
316.5
507.6
10
32.8
61.2
75
132.2
216.1
140
337.2
540.5
15
37.7
68.8
80
143.6
234.0
145
258.8
574.8
20
43.0
77.1
85
155.7
253.0
150
381.5
610.6
