Copper Pipe Size Selector
Recommend liquid and suction line diameters
Including fittings equivalent length
Height difference (indoor to outdoor)
Recommended Pipe Sizes
Target: <1°F (0.5°C) sat. temp equivalent
Target: <2°F (1°C) sat. temp equivalent
Pipe Size Reference (R-410A)
| Capacity | Liquid Line | Suction Line |
|---|---|---|
| Up to 1.5 Tons | 1/4" (6.35mm) | 3/8" (9.52mm) |
| 2 - 3 Tons | 3/8" (9.52mm) | 1/2" (12.7mm) |
| 4 - 5 Tons | 3/8" (9.52mm) | 5/8" (15.88mm) |
| 6 - 8 Tons | 1/2" (12.7mm) | 3/4" (19.05mm) |
| 10 - 12 Tons | 1/2" (12.7mm) | 7/8" (22.22mm) |
| 15 - 20 Tons | 5/8" (15.88mm) | 1-1/8" (28.58mm) |
When to upgrade pipe size:
• Pipe length > 25m (80ft)
• Elevation difference > 10m (33ft)
• Multiple bends or restrictions
Fitting Equivalent Length Reference
| Fitting Type | 1/4" | 3/8" | 1/2" | 5/8" | 3/4" | 7/8" |
|---|---|---|---|---|---|---|
| 90° Elbow (long radius) | 0.15m | 0.2m | 0.3m | 0.4m | 0.5m | 0.6m |
| 90° Elbow (short radius) | 0.25m | 0.35m | 0.5m | 0.65m | 0.8m | 1.0m |
| 45° Bend | 0.08m | 0.1m | 0.15m | 0.2m | 0.25m | 0.3m |
| Service Valve | 0.3m | 0.4m | 0.6m | 0.8m | 1.0m | 1.2m |
| Tee (flow through) | 0.1m | 0.15m | 0.2m | 0.3m | 0.35m | 0.4m |
| Tee (branch) | 0.3m | 0.4m | 0.6m | 0.8m | 1.0m | 1.2m |
Pressure Drop Targets
Liquid Line: <1°F (0.5°C) saturation temperature equivalent
Suction Line: <2°F (1°C) saturation temperature equivalent
Excessive pressure drop reduces system efficiency and capacity.
Oil Return Considerations
Vertical suction risers require minimum velocity of 3-4 m/s (600-800 FPM) to return oil to compressor. If velocity is too low, install an oil trap at the bottom of vertical risers.