A2L Safe Charge - Superheat

R-454B PT Chart & Max Charge

Free · In-App Purchases · Designed for iPad. Not verified for macOS.

Legacy Check & Charge needs a login for superheat. A2L Safe Charge stays free, offline, no account — R-454B glide handled, max safe charge built in. 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.

Ratings & Reviews

  • This app has not received enough ratings or reviews to display an overview.

• 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

Version 1.3.6

The developer, Mike Watson, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .

  • Data Used to Track You

    The following data may be used to track you across apps and websites owned by other companies:

    • Location
    • Identifiers
    • Usage Data

  • Data Linked to You

    The following data may be collected and linked to your identity:

    • Location
    • Identifiers
    • Usage Data

  • Data Not Linked to You

    The following data may be collected but it is not linked to your identity:

    • Diagnostics

Privacy practices may vary based, for example, on the features you use or your age. Learn More

The developer indicated that this app supports the following accessibility features. Learn More

  • Supported Features

    • VoiceOver

    • Voice Control

    • Dark Interface

    • Differentiate Without Colour Alone

    • Sufficient Contrast

    • Reduced Motion

Information

Provider
  • Mike Watson
Size
  • 46.1 MB
Category
  • Business
Compatibility
Requires iOS 15.1 or later.
  • iPhone
    Requires iOS 15.1 or later.
  • iPad
    Requires iPadOS 15.1 or later.
  • iPod touch
    Requires iOS 15.1 or later.
  • Mac
    Requires macOS 12.0 or later and a Mac with Apple M1 chip or later.
  • Apple Vision
    Requires visionOS 1.0 or later.
Languages
  • English
Age Rating
4+
In-App Purchases
Yes
Copyright
  • © 2026 Mike Watson
  • Developer Website
  • Privacy Policy

    • More by Mike Watson

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