General Assist Technical Reference
VRF Refrigerant Charge Calculation Sheet
How to complete and submit the refrigerant charge calculation
For supported AIRSTAGE VRF systems requiring verified additional refrigerant charge calculations
Purpose: Use this article to download the VRF Refrigerant Charge Calculation Sheet, complete the required fields, and return it for processing. The sheet standardises how additional charge is calculated and helps prevent commissioning delays caused by incomplete information.
Applies to
| Series | Application |
|---|---|
| S Series HPCO | New installations, extensions, and major pipework alterations requiring a verified refrigerant charge calculation. |
| S Series HR | |
| V Series | |
| J Series | |
| JIIS Series | |
| JII Series | |
| JIII Series | |
| JIIIL Series | |
| JIV Series | |
| JIVS Series | |
| JIVL Series | |
| VII Series | |
| VIII Series | |
| VRII Series | |
| VRIV Series |
What you need before you start
Have the following information available so the sheet can be completed in one pass:
- Site name, project reference, installer and contact details
- Outdoor unit model(s) and quantity
- Indoor unit model(s) and quantity
- Piping layout summary, including main runs, branches and risers
- Pipe sizes for liquid and gas lines
- Measured line lengths by section, including horizontal and vertical runs
- Highest vertical separation between indoor and outdoor units
- Factory refrigerant charge per outdoor unit, from the nameplate or product data
- Target commissioning date and any special notes such as long risers or oil traps
Important: Incomplete or inconsistent piping information may delay processing. Ensure the equipment schedule and piping data reconcile before submission.
How to complete the sheet
1. Project and contact details
- Enter the site name, project number or reference, company, installer name, email address and phone number.
- Add the required return date if the calculation is time-critical.
2. Equipment schedule
- List each outdoor unit model and quantity.
- List each indoor unit model and quantity.
- If the workbook contains a dedicated equipment schedule tab, ensure the quantities reconcile with the piping tab totals.
3. Piping data
- Record pipe sizes for liquid and gas lines on every section, including the main trunk and each branch.
- Enter measured lengths for each section. Separate horizontal and vertical lengths where requested.
- Record the maximum height difference and identify whether the outdoor unit is above or below the indoor units.
- Identify riser sections and long horizontal runs that may require special attention.
4. Factory charge and calculation rules
- Enter the factory refrigerant charge for each outdoor unit model from the product nameplate or specification data.
- If the sheet contains built-in charge rules, verify the units and increments match the project requirements.
5. Review the calculated results
- Confirm the additional refrigerant charge result is non-negative and appears reasonable for the recorded pipe lengths and sizes.
- Check all validation flags or highlighted cells and resolve any incomplete or inconsistent entries.
6. Attach drawings - recommended
Include a simplified pipe schematic or marked-up plan showing the pipe lengths and sizes that correspond with the values entered in the calculation sheet.
7. Save and return
- Save the file with a clear project-specific filename, for example: ProjectName_VRF_ChargeCalc.xlsx.
- Attach the completed workbook and send it to your GENERAL contact or the nominated processing address.
Quality checks before you submit
| Check | Requirement |
|---|---|
| ✓ | Indoor unit totals match the equipment schedule and piping schematic. |
| ✓ | Pipe sizes are realistic and consistent along all branches. |
| ✓ | The longest run and highest riser are clearly identified. |
| ✓ | Factory charge values are entered for every outdoor unit type. |
| ✓ | Contact information and the project reference are complete. |
Submission tip: A completed charge sheet supported by a clear piping schematic is the fastest way to confirm the required additional refrigerant charge and avoid commissioning delays.