Indicative prompts only. Interpret against equipment specifications, load and operating conditions; no automatic charge diagnosis.
Answer what you have checked. The app uses these observations alongside the plotted cycle to prioritise possible causes, not to declare a confirmed fault.
Check OEM data and pressure/temperature measurement locations. Clear sight glass does not prove correct charge; high or low superheat alone does not identify a unique fault. VRF/EEV, economised, heat-recovery and transcritical CO₂ systems need equipment-specific analysis.
Chart loads after refrigerant properties become available.
Uses CoolProp through a public Pyodide-compatible Python runtime loaded on demand. An internet connection is needed initially. The calculation uses an idealised isentropic compressor, no pressure losses, and an isenthalpic expansion valve. COP is theoretical, not measured. On blends, dew temperature is used for superheat and bubble temperature for subcooling. Condensing TD uses dew temperature, while subcooling uses bubble temperature. Quality curves are shown as dashed lines. Suction temperature should be measured at the same location as suction pressure. For meaningful condenser outlet enthalpy, measure liquid temperature at the corresponding pressure point. For CO₂, transcritical gas-cooler operation requires special handling and is not represented by the standard four-point subcritical model.
Important: this page currently offers an accurate calculation only when the CoolProp runtime loads successfully. It never substitutes invented refrigerant properties.