RefrigCharge

Built for HVAC service techs and install crews who need subcool / superheat diagnosis on the roof - not a dashboard you log into. WHAT IT DOES Computes measured subcooling and superheat from your gauge readings, compares them against per-refrigerant target windows, and tells you whether the system is undercharged, overcharged, or showing airflow issues. Charge adjustment advice differs for TXV vs. piston / cap-tube metering, matching the field workflow. REFRIGERANTS SUPPORTED - R-410A - R-22 - R-134a - R-404A - R-407C INPUTS - Refrigerant type (picker) - Metering device (TXV or Piston / Cap Tube) - Liquid line temperature - Condensing saturation temperature - Suction line temperature - Evaporating saturation temperature - °F or °C toggle RETURNS - Measured subcooling vs. target (color-coded: green within ±3°F, red outside) - Measured superheat vs. target (color-coded) - Diagnosis: undercharged, overcharged, normal, or airflow issue - Charge adjustment advice: ADD, REMOVE, or CORRECT - Adjustment basis: subcool for TXV, superheat for piston WHY THIS APP, NOT THE FREE ONES - Math is shown - measured minus target, with the per-refrigerant windows visible. - Status at a glance - color-coded so you do not have to do mental arithmetic on the ladder. - Works offline - RF-shielded basements, attics, and roofs. Always available. - No login. No ads. No telemetry. No subscription. PRICING $4.99. Pay once, own it. Lifetime access on iPhone, iPad, and Mac via Family Sharing. NOT A SUBSTITUTE FOR The manufacturer's charging procedure for your specific equipment. The equipment data plate's nameplate charge. Calibrated gauge sets. This app gives you a directional read - verify against the OEM service manual before adjusting.