# A2L Safe Charge - Superheat — R-454B PT Chart & Max Charge > HVAC refrigerant charging tool for next-generation gases with error-proof calculations. (iPhone/iPad app by Mike Watson.) - Source: https://appshunter.io/ios/app/a2l-safe-charge-superheat/id6760899340 (this page in markdown: same URL + `.md`) - Developer: [Mike Watson](https://appshunter.io/developer/1848411021) - Category: Business, Productivity - Price: Free with in-app purchases - Rating: 5.00/5 from 2 App Store ratings - Age rating: 4+ - Requires: iOS 15.1 · 45 MB - Languages: American English - Released: 2026-03-24 - Data updated: 2026-08-06 - Monetization: free with in-app purchases - User reviews in markdown: https://appshunter.io/ios/app/a2l-safe-charge-superheat/id6760899340/reviews.md ## What is A2L Safe Charge? 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. ## Key features - A2L-ready for R-454B and R-32 - Error-proof superheat/subcooling calculations - Integrated Max Allowable Charge Calculator - Branded PDF field reports - Offline P/T charts and safety guides - No account or login required ## Pricing and in-app purchases Base price: Free. **One-time purchases** | Purchase | Price | Type | | --- | --- | --- | | A2L SafeCharge Pro | $1.99 | one-time | ## Frequently asked questions about A2L Safe Charge ### What refrigerants does A2L Safe Charge support? A2L Safe Charge fully supports next-generation refrigerants R-454B and R-32, in addition to R-410A. This makes it a versatile tool for modern HVAC systems. ### How does A2L Safe Charge prevent charging errors? The app automatically applies Dew Point for superheat and Bubble Point for subcooling on R-454B. This feature eliminates the most common A2L charging mistakes, ensuring accuracy. ### Can I calculate safe refrigerant charge limits with A2L Safe Charge? Yes, A2L Safe Charge includes an integrated Max Allowable Charge Calculator. You can enter room dimensions to instantly get your safe charge limit based on current A2L safety standards. ### Does A2L Safe Charge require an internet connection? No, A2L Safe Charge offers full offline reference capabilities. This includes P/T charts, refrigerant comparisons, and safety guides, meaning you can use it without cell service. ### Can I generate reports with A2L Safe Charge? Yes, you can generate professional, branded PDF field reports directly within A2L Safe Charge. These reports can include your company name and logo and be emailed to clients. ### Is my data collected by A2L Safe Charge? A2L Safe Charge is privacy-focused and collects no data. All information and calculations performed on the job site remain on your device. ### What devices is A2L Safe Charge available on? A2L Safe Charge is available for iPhone, iPad, and iPod. It is designed for iOS devices. ### How often is A2L Safe Charge updated? The latest version of A2L Safe Charge is 1.1.1, which was last updated on April 19, 2026. Updates typically address performance improvements and feature enhancements. ## Version history (last 5 releases) ### 2.0.0 — 2026-08-02 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 ### 1.3.7 — 2026-07-28 - Improved ad configuration and reliability - Minor bug fixes and behind-the-scenes stability improvements ### 1.3.6 — 2026-07-22 • Small banner on A2L Quick Reference — same 100% free app, no paywalls • Refreshed store screenshots for R-454B / R-32 charging and max safe charge • Under-the-hood polish ### 1.3.5 — 2026-07-16 -Updated tracking on ads platform ### 1.3.3 — 2026-07-15 New field-ready calculator layout with an in-app keypad and one-tap Resume on the home screen Compare superheat/subcooling results to an optional OEM target from the nameplate ## More apps by Mike Watson - [Leafed - Private Book Tracker](https://appshunter.io/ios/app/leafed-private-book-tracker/id6754466418) - [HVAC Load Calculator Manual J](https://appshunter.io/ios/app/hvac-load-calculator-manual-j/id6758120488) - [Water Damage Report Photo Docs](https://appshunter.io/ios/app/water-damage-report-photo-docs/id6758919407) - [Pesticide Mix Calculator](https://appshunter.io/ios/app/pesticide-mix-calculator/id6759580852) - [Attentionly: Time Audit](https://appshunter.io/ios/app/attentionly-time-audit/id6761147386) All apps by Mike Watson: https://appshunter.io/developer/1848411021 --- *Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-08-06.*