Refrigerant Charge Verification
Refrigerant charge test completed on all AC and heat-pump equipment.
Spec
Applies uniformly from Silver upward.
Scope
All split-system AC and heat-pump equipment installed (factory-charged window/PTAC units excluded).
Requirements
- 01.
Verify refrigerant charge using the subcooling method (TXV systems) or superheat method (fixed-orifice systems), per ACCA Quality Installation Standard.
- 02.
Charge must fall within the manufacturer's specified target range for the system at the test conditions.
- 03.
If charge is off, adjust before sign-off and re-verify.
Documentation
Evidence the inspector / Institute will need.
- 01.
Signed refrigerant charge test record per installed unit, listing model number, outdoor temperature at test, measured superheat or subcooling, and manufacturer target range.
Guidance
Why charge matters so much
A typical residential AC system underperforms by 5-20% when charge is off by even 10%. Industry surveys consistently find 60%+ of new installations have improper charge — this requirement catches that during commissioning rather than after months of high bills.
Resources
- ACCA Standard 5 — Quality Installation →
The detailed protocol for refrigerant charge verification and overall HVAC quality installation.