Free Refrigerant Charge Calculator

Estimate the additional refrigerant charge needed for an AC system based on line set length beyond the factory charge.

ft
ft
oz/ft
oz

Additional Charge

15.0 oz

Total System Charge111.0 oz
Total Charge6.94 lbs

Additional Charge vs Total Line Set Length

Refrigerant Charge Adjustment

Additional Charge = (Line Length - Factory Length) x oz/ft

AC condensing units ship with a factory refrigerant charge that covers a standard line set (typically 25 ft). For every additional foot of liquid line, extra refrigerant must be added per the manufacturer specifications (often 0.6 oz/ft for R-410A).

Example Calculation

50 ft line set, factory covers 25 ft, R-410A at 0.6 oz/ft, 96 oz factory charge.

  1. 01Extra length = 50 - 25 = 25 ft
  2. 02Additional = 25 x 0.6 = 15.0 oz
  3. 03Total = 96 + 15 = 111 oz = 6.94 lbs

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