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Deep Technical Chapters · Charge & Metering
Refrigerant Charging
Technician
Weighing in, charging by superheat or subcooling, and not guessing.
Charge to the method the system and manufacturer specify — weigh the full charge on a new system, top up by subcooling (TXV) or superheat (fixed orifice), and never guess.
Methods
- Weigh in the full charge to nameplate
- Charge by subcooling for TXV systems
- Charge by superheat for fixed-orifice systems
- Always find and repair leaks before charging
Field Rules
- 01
"Don't add refrigerant to mask a leak. Find it, fix it, weigh it in."
Diagnosis at a glance
Common mistakes & callbacks
- •Topping up repeatedly instead of finding the leak
- •Charging by guess on a TXV system
