HVAC Toolkit: PT & Superheat

HVAC Field Toolkit is an offline field suite for residential and light-commercial HVAC techs in North America and Europe — charging math, PT lookup, psychrometrics, and EPA Section 608 study in one app, even without cell signal.

Not just another superheat calculator: work rooftops and mechanical rooms with a toolkit built for EPA-minded techs who need results they can share.

FREE TOOLS • Superheat and subcooling with °F/°C and psi/bar/kPa switching — TXV vs fixed-orifice paths • PT charts for common refrigerants — R-410A, R-32, R-454B, R-22, R-134a, R-448A, R-507A, R-717, R-290, and more • Zeotropic blends: bubble (liquid) and dew (vapor) so SH uses dew and SC uses bubble • Psychrometric calculator: dry bulb, wet bulb, dew point, RH, enthalpy, humidity ratio • Filter sizing: CFM and filter type (pleated / fiberglass / HEPA / electronic) → area, nominal size, and extra filters needed • Ventilation Check (ASHRAE 62.1 / 62.2) — quick outdoor-air minimum from occupants + floor area + measured supply CFM • Blower Fan Law — same fan / wheel, CFM ∝ RPM, SP ∝ RPM², HP ∝ RPM³ (mode: from new RPM, or solve RPM from target CFM) • Delta T, temperature/pressure converters, voltage drop • Refrigerant reference cards, favorites, and recent tools • One free PDF export preview across all 18 calculators to try job-site sharing

PRO — ONE-TIME UNLOCK ($9.99) • EPA Section 608 study: practice, timed exams, mistakes review, bookmarks, spaced repetition (Leitner 5-box), and progress dashboard • Target superheat for fixed-orifice charging (generic field chart — prefer OEM when available), with System Type filter for Mini-Split and Heat Pump • Static Pressure check — TESP (return + supply) with PASS / WARN / FAIL vs rated max, with System Class presets (Residential PSC / ECM, High-Efficiency, Light Commercial) • Charging by Weight — cylinder tare, gross, and net in lbs/oz or kg/g • Voltage Imbalance — 3-phase diagnostic per NEMA MG-1 (Vab / Vbc / Vca, imbalance %, LRA derate, status vs rated) • Compressor Amp Draw — measure 3-phase current vs. nameplate RLA + imbalance with diagnostic hints (locked rotor / single-phase / winding / undercharge / overload / non-condensables); pairs with Voltage Imbalance • Named Jobs: save and reopen field calculations • Unlimited PDF reports across all 18 calculators (Superheat, Subcooling, Psychrometrics, Delta T, Duct Sizing, Static Pressure, Charging by Weight, Voltage Imbalance, Target Superheat, Compressor Amp Draw, Capacitor, Airflow, Voltage Drop, Filter Sizing, Ventilation Check, Blower Fan Law, Temperature Converter, Pressure Converter) — share with customers or the shop • Duct sizing (equal friction / Manual D–style helpers) • Remove banner ads

BUILT FOR THE FIELD • Light and dark themes, readable industrial UI • Local history and favorites on device — no account for core tools • 18 languages for crews that work across regions

IMPORTANT Target superheat values are a generic approximation for fixed-orifice systems. Manufacturer charging charts (Carrier, Trane, Goodman, Lennox, and others) can differ. TXV and EEV systems should be charged by subcooling per OEM instructions. PT data is field-grade for service work, not a laboratory REFPROP substitute.

Download HVAC Field Toolkit — EPA study, offline PT/SH/SC, Jobs, and PDF reports in one $9.99 unlock.

What's new in v1.0.11: Compressor Amp Draw (Pro) — 3-phase current vs. nameplate RLA + imbalance with diagnostic hints; Ventilation Check (Free) — ASHRAE 62.1 / 62.2 outdoor-air minimum from occupants + floor area + measured supply; Blower Fan Law (Free) — CFM / SP / HP from RPM change.