JII Refrigerant Charge Calculator
This article explains how to use the JII refrigerant charge calculation shown in the service calculator.
- Total refrigerant charge = Factory Charge (A) + Additional Pipe Charge (B)
- 1/4 in. liquid pipe additional charge: 0.021 kg per metre
- 3/8 in. liquid pipe additional charge: 0.058 kg per metre
- Maximum system charge shown for 1 outdoor unit: 15.7 kg
Calculation Method
The calculator separates the refrigerant charge into two parts:
| Section | Description |
|---|---|
| A | Factory refrigerant charge for the selected outdoor unit model |
| B | Additional refrigerant required for the entered pipe lengths |
Total Refrigerant Charge (kg) = A + B
Step 1 - Select the Outdoor Unit
Select the applicable Outdoor 1 (Master) model in the calculator.
The calculator then provides the corresponding Factory Charge. This value becomes Section A of the calculation.
Step 2 - Enter Additional Pipe Length
Enter the applicable pipe length in metres for each pipe size shown in the calculator.
| Pipe Size | Additional Charge Rate | Calculation |
|---|---|---|
| 1/4 in. | 0.021 kg/m | Pipe length (m) x 0.021 |
| 3/8 in. | 0.058 kg/m | Pipe length (m) x 0.058 |
Add the calculated values for both pipe sizes together. This becomes Section B.
Step 3 - Calculate Total Refrigerant Charge
Add the factory charge and the additional pipe charge:
Worked Example
The following example demonstrates the calculation method only.
- Factory charge (A): 10.00 kg
- 1/4 in. pipe length: 20 m
- 3/8 in. pipe length: 30 m
1/4 in. pipe charge:
20 m x 0.021 kg/m = 0.42 kg
3/8 in. pipe charge:
30 m x 0.058 kg/m = 1.74 kg
Total additional pipe charge (B):
0.42 kg + 1.74 kg = 2.16 kg
Total system refrigerant charge:
10.00 kg + 2.16 kg = 12.16 kg
Maximum System Charge
Always compare the final calculated refrigerant quantity with the maximum system charge shown for the applicable system configuration.
Technician Checklist
- Select the correct outdoor unit model.
- Confirm the factory refrigerant charge shown by the calculator.
- Measure the applicable 1/4 in. and 3/8 in. pipe lengths.
- Calculate the additional charge using the applicable kg/m rate.
- Add all additional pipe charges together.
- Add the additional charge to the factory charge.
- Confirm the final system charge does not exceed the maximum shown by the calculator.
- Record the final refrigerant charge on the commissioning documentation.