Looking for the right capillary tube size for your refrigeration system can be a daunting task, but fear not, the R22 Capillary Tube Chart is here to help!
This chart is a lifesaver for refrigeration technicians, allowing them to choose the perfect diameter and length of capillary tube based on the system’s evaporator temperature and cooling capacity.
When it comes to sizing capillary tubes, there are a few rules to keep in mind.
- The tube’s diameter and length both play a critical role in determining its total restriction. Interestingly, even a slight percentage change in diameter can have a more significant impact on flow than a change in length.
- You can also change the restriction by altering the tube’s length. Longer tubes result in slower flow rates, so going to extreme lengths to increase restriction may not always be the best idea. Once the pipe length decreases, the flow rate gradually increases until it reaches a critical point where the flow rate starts to rise rapidly with each reduction in length.
- However, when the pipe becomes too short, even small changes in length can cause significant increases in flow. At this point, the tube starts acting more like an orifice than a capillary tube.
- As a general rule of thumb, it’s best to keep your capillary tube length between 5 and 16 feet. Of course, there are always exceptions, but staying within this range for day-to-day operations can help eliminate many problems.
When using the R22 Capillary Tube Chart, the evaporator temperature is the first parameter to consider. Take into account:
| Temperature of evaporator | Temperature of Condenser | |
| LBP | -23,3 °C -10°F | 54,4 °C 130°F |
| MBP | -6,7 °C 20°F | 54,4 °C 130°F |
| HBP | 7,2 °C 45°F | 54,4 °C 130°F |
1 HP = 746W
| Power electric Compressor HP | Temperature of Evaporator | Diameter in | Length m |
| 1/4 HP | HBP | 0,050 in | 3,0m |
| 1/4 HP | MBP | 0,036 in | 2,5m |
| 1/3 HP | HBP | 0,05in | 2,0m |
| 1/3 HP | MBP | 0,042 in | 3,0m |
| 1/2 HP | HBP | 0,050in | 1,5m |
| 1/2 HP | MBP | 0,042in | 2,0m |
| 1 HP | HBP | 0,064in | 1,5m |
| 1 HP | MBP | 0,050 | 2,0m |
| 1 1/4 HP | HBP | 0,064 | 1,5m |
| 1 1/4 HP | MBP | 0,064 | 1,0m |
| 1 1/4 HP | HBP | 0,064 | 1,5m |
| 1 1/4 HP | MBP | 0,064 | 1,0m |
Cooling Capacity
It is the cooling capacity of a compressor at a given evaporation temperature of refrigerant r22. It represents a base parameter for selection, it is measured in Btu/h, Kcal/h and some models in the international system use W, it should not be confused with electrical power, because in this case we are talking about energy in the form of heat.
| Cooling Capacity | Temperature of Evaporator -10 °F | Temperature of Evaporator 25 °F | Temperature of Evaporator 45 °F |
| 750 Btu/h 185 Kcal/h | 0.028″ – 15 ft | 0.028″ – 14 ft | 0.028″ – 13½ ft |
| 1000 Btu/h 250 Kcal/h | 0.028″ – 8 ft | 0.028″ – 7½ ft | 0.028″ – 7 ft |
| 1250 Btu/h 312 Kcal/h | 0.028″ – 5 ft | 0.028″ – 4½ ft ft | 0.028″ – 4½ |
| 1500 Btu/h 375 Kcal/h | 0.031″ – 6 ft | 0.031″ – 5½ ft | 0.031″ – 5 ft |
| 2000 Btu/h 500 Kcal/h | 0.040″ – 13 ft | 0.040″ – 12½ ft | 0.040″ – 12 ft |
| 3000 Btu/h 750 Kcal/h | 0.040″ – 5½ ft | 0.040″ – 5 ft | 0.040″ – 5 ft |
| 4000 Btu/h 1000 Kcal/h | 0.052″ – 13 ft | 0.052″ – 12 ft | 0.052″ – 11½ ft |
| 6000 Btu/h 1500 Kcal/h | 0.052″ – 5½ ft | 0.052″ – 5 ft | 0.052″ – 5 ft |
| 8000 Btu/h 2000 Kcal/h | 0.064″ – 9 ft | 0.064″ – 8½ ft | 0.064″ – 8½ ft |
| 10000 Btu/h 2500 Kcal/h | 0.064″ – 5½ ft | 0.064″ – 5½ ft | 0.064″ – 5 ft |
| 12,000 Btu/h 3000 Kcal/h | 0.064″ – 4 ft | 0.052″ – 5 ft (2) | 0.052″ – 5 ft (2) |
| Length Capillary meters | 0,6 mm | 0,6 mm | 0,7 mm | 0,7 mm | 0,8 mm | 0,8 mm | 0,9 mm | 0,9 mm |
| -30 °C | -23,3 °C | -30 °C | -23,3 °C | -30 °C | -23,3 °C | -30 °C | -23,3 °C | |
| 100 Kcal/h 400 Btu/h | 2,63 m | 2,76 m | ||||||
| 120 Kcal/h 480 Btu/h | 1,81 | 1,90 | ||||||
| 130 Kcal/h 520 Btu/h | 1,54 | 1,62 | ||||||
| 140 Kcal/h 560 Btu/h | 1,33 | 1,39 | 3,06 | 3,20 | ||||
| 150 Kcal/h 600 Btu/h | 1,15 | 1,21 | 2,66 | 2,79 | ||||
| 160 Kcal/h 640 Btu/h | 1,01 | 1,06 | 2,33 | 2,45 | ||||
| 170 Kcal/h 680 Btu/h | 2,07 | 2,17 | ||||||
| 180 Kcal/h 720 Btu/h | 1,84 | 1,93 | ||||||
| 190 Kcal/h 760 Btu/h | 1,65 | 1,73 | 3,42 | 3,58 | ||||
| 200 Kcal/h 800 Btu/h | 1,49 | 1,56 | 3,08 | 3,23 | ||||
| 215 Kcal/h 860 Btu/h | 1,29 | 1,35 | 2,65 | 2,78 | ||||
| 230 Kcal/h 920 Btu/h | 1,12 | 1,18 | 2,31 | 2,42 | ||||
| 245 Kcal/h 980 Btu/h | 0,99 | 1,04 | 2,03 | 2,13 | ||||
| 260 Kcal/h 1040 Btu/h | 1,80 | 1,89 | 3,42 | 3,59 | ||||
| 275 Kcal/h 1100 Btu/h | 1,60 | 1,68 | 3,05 | 3,20 | ||||
| 300 Kcal/h 1200 Btu/h | 1,34 | 1,41 | 2,55 | 2,68 | ||||
| 320 Kcal/h 1280 Btu/h | 1,17 | 1,23 | 2,23 | 2,35 | ||||
| 340 Kcal/h 1360 Btu/h | 1,04 | 1,09 | 1,97 | 2,07 | ||||
| 360 Kcal/h 1440 Btu/h | 1,75 | 1,84 | ||||||
| 380 Kcal/h 1520 Btu/h | 1,57 | 1,65 | ||||||
| 400 Kcal/h 1600 Btu/h | 1,41 | 1,48 | ||||||
| 450 Kcal/h 1800 Btu/h | 1,11 | 1,17 |
| Length Capillary meters | 1 mm | 1 mm | 1,2 mm | 1.2 mm | 1,5 mm | 1.5 mm |
| -30 °C | -23,3 °C | -30 °C | -23,3 °C | -30 °C | -23,3 °C | |
| 340 Kcal/h 1360 Btu/h | 3,53 m | 3,70 m | ||||
| 360 Kcal/h 1440 Btu/h | 3,13 | 3,29 | ||||
| 380 Kcal/h 1520 Btu/h | 2,80 | 2,94 | ||||
| 400 Kcal/h 1600 Btu/h | 2,52 | 2,64 | ||||
| 450 Kcal/h 1800 Btu/h | 1,97 | 2,07 | ||||
| 500 Kcal/h 2000 Btu/h | 1,58 | 1,66 | ||||
| 550 Kcal/h 2200 Btu/h | 1,30 | 1,36 | 3,56 | 3,74 | ||
| 600 Kcal/h 2400 Btu/h | 1,08 | 1,14 | 2,96 | 3,11 | ||
| 650 Kcal/h 2600 Btu/h | 0,92 | 0,96 | 2,50 | 2,63 | ||
| 700 Kcal/h 2800 Btu/h | 2,14 | 2,25 | ||||
| 750 Kcal/h 3000 Btu/h | 1,85 | 1,95 | ||||
| 800 Kcal/h 3200 Btu/h | 1,62 | 1,70 | ||||
| 850 Kcal/h 3400 Btu/h | 1,42 | 1,50 | ||||
| 900 Kcal/h 3600 Btu/h | 1,26 | 1,33 | ||||
| 950 Kcal/h 3800 Btu/h | 1,13 | 1,18 | ||||
| 1000 Kcal/h 4000 Btu/h | 1,01 | 1,06 | 3,58 | 3,68 | ||
| 1100 Kcal/h 4400 Btu/h | 2,97 | 3,01 | ||||
| 1200 Kcal/h 4800 Btu/h | 2,51 | 2,50 | ||||
| 1300 Kcal/h 5200 Btu/h | 2,14 | 2,11 | ||||
| 1400 Kcal/h 5600 Btu/h | 1,85 | 1,80 | ||||
| 1500 Kcal/h 6000 btu/h | 1,62 | 1,56 | ||||
| 1600 Kcal/h 6400 Btu/h | 1,43 | 1,36 |
| Length Capillary meters | 0,7 mm | 0.7 mm | 0,8 mm | 0.8 mm | 0,9 mm | 0.9 mm | 1 mm | 1 mm |
| kcal/h | 5 °C | 7,2 °C | 5 °C | 7,2 °C | 5 °C | 7,2 °C | 5 °C | 7,2 °C |
| 100 | ||||||||
| 120 | 4,54 | 4,68 | ||||||
| 130 | 3,90 | 4,02 | ||||||
| 140 | 3,36 | 3,47 | ||||||
| 150 | 2,92 | 3,03 | ||||||
| 160 | 2,59 | 2,68 | ||||||
| 170 | 2,29 | 2,37 | 4,67 | 4,82 | ||||
| 180 | 2,04 | 2,11 | 4,16 | 4,30 | ||||
| 190 | 1,83 | 1,89 | 3,73 | 3,88 | ||||
| 200 | 1,66 | 1,72 | 3,40 | 3,52 | ||||
| 215 | 1,43 | 1,49 | 2,94 | 3,04 | ||||
| 230 | 1,25 | 1,30 | 2,56 | 2,65 | 4,79 | 4,95 | ||
| 245 | 1,09 | 1,14 | 2,26 | 2,35 | 4,26 | 4,41 | ||
| 260 | 1,01 | 2,01 | 2,09 | 3,79 | 3,92 | |||
| 275 | 1,80 | 1,87 | 3,38 | 3,50 | ||||
| 300 | 1,50 | 1,56 | 2,83 | 2,94 | 5,00 | |||
| 320 | 1,31 | 1,37 | 2,50 | 2,60 | 4,40 | 4,55 | ||
| 340 | 1,16 | 1,22 | 2,21 | 2,30 | 3,89 | 4,02 | ||
| 360 | 1,04 | 1,09 | 1,97 | 2,05 | 3,46 | 3,58 | ||
| 380 | 1,76 | 1,83 | 3,12 | 3,24 | ||||
| 400 | 1,58 | 1,65 | 2,82 | 2,93 | ||||
| 450 | 1,25 | 1,31 | 2,22 | 2,31 | ||||
| 500 | 1,05 | 1,78 | 1,86 | |||||
| 550 | 1,47 | 1,54 | ||||||
| 600 | 1,23 | 1,29 | ||||||
| 650 | 1,03 | 1,09 |
| Length Capillary meters | 1,2 nn | 1.2 nn | 1,5 nn | 1.5 mm |
| kcal/h | 5 °C | 7,2 °C | 5 °C | 7,2 °C |
| 500 | 4,76 m | 4,93 m | ||
| 550 | 3,96 | 4,11 | ||
| 600 | 3,32 | 3,45 | ||
| 650 | 2,82 | 2,93 | ||
| 700 | 2,41 | 2,52 | ||
| 750 | 2,09 | 2,18 | ||
| 800 | 1,84 | 1,93 | ||
| 850 | 1,63 | 1,71 | ||
| 900 | 1,44 | 1,52 | 4,87 | |
| 950 | 1,28 | 1,35 | 4,36 | 4,53 |
| 1000 | 1,15 | 1,21 | 3,92 | 4,07 |
| 1100 | 3,21 | 3,35 | ||
| 1200 | 2,71 | 2,84 | ||
| 1300 | 2,30 | 2,41 | ||
| 1400 | 1,96 | 2,06 | ||
| 1500 | 1,69 | 1,78 | ||
| 1600 | 1,46 | 1,55 |
