HVAC Calc: Superheat & P/T

Fully offline HVAC field calc: refrigerant P/T, target superheat & subcooling, delta-T, duct sizing, airflow. One-time Pro unlock - no subscription, no ads, no sign-in.

The HVAC technician's calculator that works where you do - on the rooftop, in the mechanical room, in the dead zone.

HVAC Tech is a fast, no-nonsense field calculator for technicians, installers, estimators, and apprentices. Six pro calculators, grounded in published refrigerant data and standard field methods, all running 100% on your phone. No account. No login. No internet. Just answers.

FULLY OFFLINE - ALWAYS Rooftops, crawlspaces, new construction with no service - HVAC Tech needs zero signal. Every P/T table, every formula, every result is computed on-device. Your data never leaves your phone because there's nothing to send.

SIX PRO CALCULATORS

• Superheat: target (fixed-orifice charging chart or TXV range) vs. actual, with a charge read and the saturation temperature.
• Subcooling: target vs. actual, with a charge read.
• Refrigerant P/T Chart: pressure to saturation temperature, with separate bubble and dew points for glide blends.
• Delta-T: supply/return temperature split vs. a humidity-based target range, with typical-cause guidance.
• Duct Sizing: CFM to round or rectangular duct size and air velocity.
• Airflow & Tonnage: CFM to tons and back (400 CFM/ton, adjustable) plus fan-law RPM changes (CFM, static, and BHP).

FREE FOREVER All six calculators, unlimited use, on R-410A and R-22 - no trial, no ads, no sign-in. Plus up to three saved jobs.

ONE-TIME PRO. NO SUBSCRIPTION. EVER. Unlock HVAC Tech Pro once for $9.99 and keep it:

• Every refrigerant: R-454B, R-32, R-134a, R-404A and R-407C - the A2L blends shipping in new equipment and the commercial ones - across superheat, subcooling and the P/T chart.
• Glide-aware readings: separate bubble and dew points on every blend.
• Unlimited saved jobs.
• PDF and share export. One payment, handled by Apple. No monthly fee, no renewal.

SAVE THE JOB Tag any reading as a saved job - unit, call, and the numbers - one tap away.

HVAC Tech is an estimation aid and is not a substitute for proper diagnostic procedures. Always verify results against the manufacturer's charging charts and target values.