106
SERVICE HANDBOOK
Capillary Tube Sizing
Suggested Capillary Tube Data for Domestic and Commercial Refrigeration
Applications
The following suggestions listed in Table A-1 and the correction factors listed in Table A-2
assume a 115°F liquid temperature, no subcooling prior to the heat exchanger, and 3 ft of
heat exchange with the suction line.
Capillary tube capacity data was generated using the Wolf and Pate 2002 correlation
(ASHRAE Research Project, RP-948)
Example No. 1
Select the capillary required for a Tecumseh R-22 compressor model AEA5460EXA rated
at 6,000 Btu/h at 45°F evaporator. Table A-1, we find 13 ft length of 0.064 in capillary tube.
Example No. 2
Select the capillary required for a Tecumseh R-134a compressor model AJA7461YXA rated
at 6,110 Btu/h at 20°F evaporator. From Table A-1, we find 9 ft length of 0.052 in capillary
tube, 2 required piped in parallel.
Table A-1: Capillary tube selections assume a 115°F liquid temperature and 3
ft of heat exchange length
Refrigerant Btu/h per circuit
22
134a
10,000
12,000
Capillary Tube, Length - OD
-10
500
19 ft - 0.026"
750
12 ft - 0.028"
1,000
11 ft - 0.031"
1,250
16 ft - 0.036"
1,500
11 ft - 0.036"
2,000
14 ft - 0.042"
3,000
19 ft - 0.052"
4,000
10 ft - 0.052"
6,000
14 ft - 0.064"
8,000
10 ft - 0.052" (2)
10,000
13 ft - 0.059" (2)
12,000
14 ft - 0.064" (2)
500
14 ft - 0.028"
750
10 ft - 0.031"
1,000
12 ft - 0.036"
1,250
18 ft - 0.042"
1,500
12 ft - 0.042"
2,000
22 ft - 0.052"
3,000
9 ft - 0.052"
4,000
10 ft - 0.059"
6,000
9 ft - 0.052" (2)
8,000
10 ft - 0.059" (2)
10 ft - 0.064" (2)
10 ft - 0.059" (3)
Evaporator Temperature, °F
20
18 ft - 0.026"
11 ft - 0.028"
10 ft - 0.031"
15 ft - 0.036"
10 ft - 0.036"
13 ft - 0.042"
18 ft - 0.052"
10 ft - 0.052"
13 ft - 0.064"
10 ft - 0.052" (2)
12 ft - 0.059" (2)
13 ft - 0.064" (2)
14 ft - 0.028"
10 ft - 0.031"
12 ft - 0.036"
18 ft - 0.042"
12 ft - 0.042"
22 ft - 0.052"
9 ft - 0.052"
10 ft - 0.059"
9 ft - 0.052" (2)
10 ft - 0.059" (2)
10 ft - 0.064" (2)
10 ft - 0.059" (3)
45
17 ft - 0.026"
10 ft - 0.028"
10 ft - 0.031"
15 ft - 0.036"
10 ft - 0.036"
13 ft - 0.042"
18 ft - 0.052"
9 ft - 0.052"
13 ft - 0.064"
9 ft - 0.052" (2)
12 ft - 0.059" (2)
13 ft - 0.064" (2)
14 ft - 0.028"
10 ft - 0.031"
12 ft - 0.036"
18 ft - 0.042"
12 ft - 0.042"
22 ft - 0.052"
9 ft - 0.052"
10 ft - 0.059"
9 ft - 0.052" (2)
10 ft - 0.059" (2)
10 ft - 0.064" (2)
10 ft - 0.059" (3)