About this app
The field calculator built for the A2L transition. Legacy Check & Charge is gone, and its replacement now needs a login just to run a superheat calculation. A2L Safe Charge is the same fast, no-account tool techs relied on — rebuilt for R-454B and R-32, with the one thing most field apps quietly skip: handling A2L glide correctly, automatically. ON A 454B CHANGE-OUT Enter suction pressure and line temperature, get superheat with dew point applied for you. Run subcooling the same way with bubble point. Then open Max Allowable Charge, enter room size and unit location, and confirm you’re under the passive safe charge limit before you leave the job. WHY TECHS SWITCH • Built on NIST REFPROP data — the same thermodynamic reference OEMs use, cited on every result, not a proprietary chart • Automatically uses dew point for superheat and bubble point for subcooling on R-454B — the #1 A2L charging mistake, handled for you • Superheat and subcooling calculator for R-454B, R-32, and R-410A • Enter your OEM nameplate target and see how your reading compares instantly • Max allowable charge calculator — enter room dimensions and unit location, get a passive charge limit based on A2L safety guidelines • Save job history and export a professional one-page PDF field report with your company branding • A2L quick reference — refrigerant comparison, bubble/dew point explainer, and A2L safety rules — all offline BUILT FOR THE FIELD No account, no login, no signal required. Basement, attic, mechanical room with zero bars — it opens fast and gives you a clear answer. Your job data stays on your phone. 100% FREE Every feature is included — calculators, history, PDF reports. A small ad keeps it free. No subscriptions, no paywalls, no upsells.
Latest release
What’s New
Nameplate check against the room charge limit with a clear Within / Exceeds result and margin Charge tier guidance (m1 / m2 / m3) plus optional active-mitigation limit, with GPS-stamped PDF job tickets when location is available
Audience growth
Ratings growth
Baseline captured. Growth appears after the crawler observes a changed rating count.
Momentum comes from crawler snapshots for the tracked storefront. “Viral growth signal” means unusually fast recent rating gains; it is an indicator, not download data.
Price tracking
Price intelligence
First snapshot captured. The trend line starts after the next crawler price observation.
- First observed Aug 11, 2026 · 7:22 AM Free
Screenshots
