Superheat Calculator - HVAC

HVAC Superheat & Subcool Calculator is the professional field diagnostic tool for AC service and system commissioning. Calculate superheat, subcooling, and saturation for 10 refrigerants including R-410A, R-454B (EPA 608 transition), and R-32 with smart charge diagnostics and color-coded results for instant field diagnostics. FEATURES: Instant Superheat & Subcooling Calculation — Get results in seconds Smart Charge Diagnostics — Normal, Low, or High with recommendations 10 Refrigerants Supported — R-410A, R-22, R-454B, R-32, R-407C, R-134a, R-404A, R-507A, R-290, R-717 Metering Device Support — TXV (expansion valve) or fixed orifice Color-Coded Results — Green/yellow/red for quick decisions P-T Saturation Data — NIST REFPROP-grade, verified against manufacturer charts Zeotropic Blend Support — Correct bubble/dew handling for blends 100% OFFLINE: All refrigerant data built-in. Works on job sites without cellular coverage. HOW IT WORKS: 1. Select refrigerant (R-410A, R-454B, R-32, etc.) 2. Select metering device (TXV or fixed orifice) 3. Enter suction pressure & temperature 4. Enter liquid pressure & temperature 5. Get instant superheat, subcooling & charge diagnosis UNDERSTANDING RESULTS: Superheat — Temperature rise above saturation on low side. Normal 10-20°F TXV, 15-25°F fixed orifice. Low indicates overcharge; high indicates undercharge or low airflow. Subcooling — Temperature drop below saturation on high side. Normal 10-20°F. Low indicates undercharge; high indicates overcharge. DIAGNOSTICS: Green — Normal charge, optimal operation Yellow — Borderline condition requiring attention Red — Undercharge, overcharge, or airflow issue SUPPORTED REFRIGERANTS: R-410A (residential), R-22 (legacy), R-454B (EPA replacement), R-32 (mini-splits), R-407C (commercial), R-134a (auto AC), R-404A (refrigeration), R-507A (low-temp), R-290 (propane), R-717 (ammonia) OPTIONAL PRO UPGRADE — $2.99 ONE-TIME IN-APP PURCHASE The following features require a separate one-time in-app purchase. They are not required to use the calculator: • Unlimited saved calculation history • PDF export of results • Dark theme • Ad-free experience USE CASES: AC service calls, refrigerant charge diagnostics, equipment commissioning, troubleshooting complaints, EPA 608 certification study, preventive maintenance checks, system optimization, R-454B transition preparation. PERFECT FOR: HVAC technicians, refrigeration mechanics, AC contractors, HVAC apprentices, building engineers, commissioning specialists, HVAC students. All P-T saturation data from NIST REFPROP-grade equations of state, cross-checked against manufacturer charts, covering -60°F to +150°F, with correct bubble/dew blend calculations. Part of HVACTools Suite — professional HVAC technician tools for field service and diagnostics.