Refrigerant Charge Calculator Formula
Understand the math behind the refrigerant charge calculator. Each variable explained with a worked example.
Formulas Used
Additional Charge
additional_oz = extra_length * oz_per_ftTotal System Charge
total_charge_oz = factory_charge_oz + extra_length * oz_per_ftTotal Charge
total_charge_lbs = (factory_charge_oz + extra_length * oz_per_ft) / 16Variables
| Variable | Description | Default |
|---|---|---|
line_length | Total Line Set Length(ft) | 50 |
factory_length | Factory Charge Covers(ft) | 25 |
oz_per_ft | Refrigerant per Extra Foot(oz/ft) | 0.6 |
factory_charge_oz | Factory Charge(oz) | 96 |
extra_length | Derived value= line_length > factory_length ? line_length - factory_length : 0 | calculated |
How It Works
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).
Worked Example
50 ft line set, factory covers 25 ft, R-410A at 0.6 oz/ft, 96 oz factory charge.
line_length = 50factory_length = 25oz_per_ft = 0.6factory_charge_oz = 96
- 01Extra length = 50 - 25 = 25 ft
- 02Additional = 25 x 0.6 = 15.0 oz
- 03Total = 96 + 15 = 111 oz = 6.94 lbs
Ready to run the numbers?
Open Refrigerant Charge Calculator