For proper refrigerant line sizing in HVAC and refrigeration systems
Proper refrigerant line sizing is critical for system performance, efficiency, and longevity. This guide provides sizing recommendations for common refrigerants and system capacities.
Key considerations for refrigerant line sizing:
The following tables provide recommended pipe sizes for R410A refrigerant systems. All sizes are in inches OD (outside diameter).
| System Capacity (Tons) |
System Capacity (BTU/h) |
Line Size Up to 25 ft |
Line Size 25-50 ft |
Line Size 50-100 ft |
Line Size Over 100 ft |
Max Recommended Length (ft) |
|---|---|---|---|---|---|---|
| 1.0 | 12,000 | 5/8" | 5/8" | 3/4" | 3/4" | 150 |
| 1.5 | 18,000 | 5/8" | 3/4" | 3/4" | 7/8" | 150 |
| 2.0 | 24,000 | 3/4" | 3/4" | 7/8" | 7/8" | 175 |
| 2.5 | 30,000 | 3/4" | 7/8" | 7/8" | 1-1/8" | 175 |
| 3.0 | 36,000 | 3/4" | 7/8" | 1-1/8" | 1-1/8" | 175 |
| 3.5 | 42,000 | 7/8" | 1-1/8" | 1-1/8" | 1-1/8" | 200 |
| 4.0 | 48,000 | 7/8" | 1-1/8" | 1-1/8" | 1-3/8" | 200 |
| 5.0 | 60,000 | 1-1/8" | 1-1/8" | 1-3/8" | 1-3/8" | 200 |
| 7.5 | 90,000 | 1-3/8" | 1-3/8" | 1-5/8" | 1-5/8" | 225 |
| 10.0 | 120,000 | 1-5/8" | 1-5/8" | 1-5/8" | 2-1/8" | 225 |
| System Capacity (Tons) |
System Capacity (BTU/h) |
Line Size Up to 25 ft |
Line Size 25-50 ft |
Line Size 50-100 ft |
Line Size Over 100 ft |
Max Recommended Length (ft) |
|---|---|---|---|---|---|---|
| 1.0 | 12,000 | 1/4" | 1/4" | 3/8" | 3/8" | 150 |
| 1.5 | 18,000 | 1/4" | 1/4" | 3/8" | 3/8" | 150 |
| 2.0 | 24,000 | 3/8" | 3/8" | 3/8" | 1/2" | 175 |
| 2.5 | 30,000 | 3/8" | 3/8" | 3/8" | 1/2" | 175 |
| 3.0 | 36,000 | 3/8" | 3/8" | 1/2" | 1/2" | 175 |
| 3.5 | 42,000 | 3/8" | 3/8" | 1/2" | 1/2" | 200 |
| 4.0 | 48,000 | 3/8" | 1/2" | 1/2" | 5/8" | 200 |
| 5.0 | 60,000 | 1/2" | 1/2" | 5/8" | 5/8" | 200 |
| 7.5 | 90,000 | 1/2" | 5/8" | 5/8" | 3/4" | 225 |
| 10.0 | 120,000 | 5/8" | 5/8" | 3/4" | 3/4" | 225 |
The following tables provide recommended pipe sizes for R407C refrigerant systems. All sizes are in inches OD (outside diameter).
| System Capacity (Tons) |
System Capacity (BTU/h) |
Line Size Up to 25 ft |
Line Size 25-50 ft |
Line Size 50-100 ft |
Line Size Over 100 ft |
Max Recommended Length (ft) |
|---|---|---|---|---|---|---|
| 1.0 | 12,000 | 5/8" | 3/4" | 3/4" | 7/8" | 150 |
| 1.5 | 18,000 | 3/4" | 3/4" | 7/8" | 7/8" | 150 |
| 2.0 | 24,000 | 3/4" | 7/8" | 7/8" | 1-1/8" | 175 |
| 2.5 | 30,000 | 7/8" | 7/8" | 1-1/8" | 1-1/8" | 175 |
| 3.0 | 36,000 | 7/8" | 1-1/8" | 1-1/8" | 1-3/8" | 175 |
| 3.5 | 42,000 | 1-1/8" | 1-1/8" | 1-3/8" | 1-3/8" | 200 |
| 4.0 | 48,000 | 1-1/8" | 1-1/8" | 1-3/8" | 1-3/8" | 200 |
| 5.0 | 60,000 | 1-1/8" | 1-3/8" | 1-3/8" | 1-5/8" | 200 |
| 7.5 | 90,000 | 1-3/8" | 1-5/8" | 1-5/8" | 2-1/8" | 225 |
| 10.0 | 120,000 | 1-5/8" | 1-5/8" | 2-1/8" | 2-1/8" | 225 |
When calculating total equivalent length, add the following values for each fitting in the system.
| Fitting Type | 3/8" | 1/2" | 5/8" | 3/4" | 7/8" | 1-1/8" | 1-3/8" | 1-5/8" | 2-1/8" |
|---|---|---|---|---|---|---|---|---|---|
| 90° Elbow | 1.0 | 1.5 | 2.0 | 2.5 | 3.0 | 4.0 | 5.0 | 6.0 | 7.0 |
| 45° Elbow | 0.5 | 0.8 | 1.0 | 1.3 | 1.5 | 2.0 | 2.5 | 3.0 | 3.5 |
| Tee (Branch) | 3.0 | 4.5 | 5.5 | 6.5 | 7.5 | 9.0 | 11.0 | 13.0 | 17.0 |
| Tee (Run) | 0.5 | 0.8 | 1.0 | 1.5 | 1.5 | 2.0 | 2.5 | 3.0 | 4.0 |
| Check Valve | 3.0 | 4.0 | 5.0 | 6.0 | 7.0 | 10.0 | 12.0 | 15.0 | 20.0 |
| Globe Valve | 15.0 | 20.0 | 25.0 | 30.0 | 35.0 | 45.0 | 55.0 | 65.0 | 85.0 |
| Ball Valve | 0.5 | 1.0 | 1.5 | 2.0 | 2.5 | 3.0 | 4.0 | 5.0 | 6.0 |
For suction line risers (refrigerant flowing upward to the compressor):
Note: In systems with long risers, consider reducing pipe size by one size to maintain proper velocity for oil return. Consult manufacturer specifications.
For installations exceeding the maximum recommended lengths: