Lineset Sizing Calculator
Determine refrigerant line sizes for mini-splits and split systems
Indoor unit higher than outdoor
Recommended Lineset Sizes
Liquid Line (Small)
-
-
Type L Copper - High pressure liquid refrigerant
Suction Line (Large)
-
-
Type L Copper - Low pressure vapor refrigerant
Max Line Length
-
Max Elevation
-
Pre-Charge Coverage
-
Refrigerant Charge Adjustment
Additional Charge Needed:
-
Charge Rate:
-
Important Notes
- • Always verify sizes with manufacturer's installation manual for your specific model.
- • Pre-charged linesets are typically available in 15ft, 25ft, and 50ft lengths.
- • Longer runs may require larger suction lines to minimize pressure drop.
- • Add oil trap (P-trap) if indoor unit is more than 15ft above outdoor unit.
- • Use nitrogen pressure test (350-500 psi) before refrigerant charging.
Standard Lineset Sizes by Capacity
| Capacity | Liquid Line (OD) | Suction Line (OD) | Max Length* | Pre-charge |
|---|---|---|---|---|
| 6,000 - 9,000 BTU | 1/4" (6.35mm) | 3/8" (9.52mm) | 50-65 ft | 25 ft |
| 12,000 BTU (1 Ton) | 1/4" (6.35mm) | 3/8" (9.52mm) | 50-65 ft | 25 ft |
| 18,000 BTU (1.5 Ton) | 1/4" (6.35mm) | 1/2" (12.7mm) | 65-75 ft | 25 ft |
| 24,000 BTU (2 Ton) | 3/8" (9.52mm) | 5/8" (15.88mm) | 75-100 ft | 25 ft |
| 30,000 - 36,000 BTU | 3/8" (9.52mm) | 5/8" - 3/4" (15.88-19.05mm) | 100-130 ft | 25 ft |
| 42,000 - 48,000 BTU | 3/8" (9.52mm) | 3/4" (19.05mm) | 130-165 ft | 25 ft |
| 60,000 BTU (5 Ton) | 3/8" - 1/2" (9.52-12.7mm) | 7/8" (22.22mm) | 165-200 ft | 25-50 ft |
* Maximum lengths vary by manufacturer. Always consult installation manual.
Copper Tubing Types for HVAC
Type L (Recommended)
- • Wall Thickness: Medium
- • Color Code: Blue
- • Use: Indoor/Outdoor refrigerant lines
- • Pressure Rating: Up to 710 psi
- • Most common for HVAC applications
Type K (Heavy)
- • Wall Thickness: Thickest
- • Color Code: Green
- • Use: Underground, high pressure
- • Pressure Rating: Up to 895 psi
- • Used for buried refrigerant lines
ACR Tubing
- • Wall Thickness: Medium (Type L)
- • Color Code: N/A
- • Use: Factory cleaned & capped
- • Feature: Nitrogen charged
- • Ready for refrigerant - no cleaning needed
Installation Guidelines
Line Routing
- Keep lines as short as possible
- Minimize bends and elbows (each 90° = 5ft equivalent)
- Use long radius bends when possible
- Slope horizontal runs toward outdoor unit
- Insulate suction line to prevent condensation
Elevation Considerations
- Indoor above outdoor: Add oil trap every 15-20ft
- Max elevation typically 50ft (15m) for mini-splits
- Indoor below outdoor: Usually less restrictive
- Additional charge often needed for elevation
Common Mistakes to Avoid
- • Using undersized suction line (causes oil return issues)
- • Kinking copper tubing during installation
- • Not purging lines with nitrogen before brazing
- • Failing to pressure test before charging
- • Not insulating suction line completely
- • Exceeding maximum line length without upsizing