Make the temperature difference clear.
Calculate superheat and subcooling from your pressure and measured line temperature. Confirm the refrigerant, mode, and units before interpreting the result.
HVAC Charge ProClarity at the service valve.
Superheat &
Subcooling.
Made Clear.
Get superheat and subcooling from your gauge and line readings, with a built-in refrigerant P-T reference, saved jobs and PDF reports. Made for HVAC technicians on iPhone.
- Calculations work offline
- No account required
- Nine refrigerants
- English and Spanish
Core calculations, offlineWork locally, without a connection.
Your jobs, on your deviceKeep a practical record of field work.
No required accountOpen your tools and get to work.
See the real app
Built around the reading
you take at the valve.
Six screens from HVAC Charge Pro, from the first reading to the finished report. Use the arrows or swipe.
Screens are real captures of HVAC Charge Pro with demonstration data, shown as in the Pro experience. Free includes three successful calculations in total, PDF sharing from those results, the basic P-T reference, the unit converter and the refrigerant list. Pro ($5.99 per month or $49.99 per year in the United States, purchased through Apple) adds unlimited calculations, Saved Jobs, PDF reports from saved job records and Advanced P-T Reference.
The essentials, within reach
From a measurement
to a useful reference.
A focused toolkit for the moments between checking your instruments and making a service decision.
Pressure and temperature, connected.
Look up saturation temperature from gauge pressure on an offline refrigerant P-T reference. Pro adds Advanced P-T Reference with two-way lookup, full tables and refrigerant comparison. Cross-check against the equipment manufacturer’s requirements.
Keep the context with the job.
Save a calculation with its job details on your device, then recalculate it later. Update the existing job or save the new readings as a new job, and share a professional PDF report.
Made for the service workflow
Less between you
and the task.
An iOS utility built around the work, with local calculations and a straightforward path back to your records.
- Useful where connectivity is limited.Core calculations work locally. Apple purchase, restore, and subscription services may require internet access.
- A private, on-device job workflow.Saved jobs remain on your device. No required account, advertising, or third-party analytics SDK.
- Measurements deserve context.Use the result alongside instrument checks, equipment documentation, and approved service procedures.
Reference data
Nine refrigerants,
stored offline.
Superheat uses the dew point and subcooling uses the bubble point, so blends are read on the correct side of the curve.
- R-22
- R-32
- R-134a
- R-404A
- R-407C
- R-410A
- R-448A
- R-449A
- R-454B
Saturation data is bundled in the app and generated with CoolProp 8.0.0. Gauge pressure uses a standard sea-level reference with no altitude correction. Superheat and subcooling are calculated from your readings; the app does not provide target values, so keep the manufacturer’s data handy.
How bubble point and dew point differ ↗HVAC CHARGE PROA toolkit worth keeping
A toolkit worth keeping
in your field workflow.
Calculations, reference, and job continuity support the same goal: a more organized approach to service work.
Download on the App StoreFree to try. Pro to keep going.
Monthly$5.99per month
Yearly$49.99per year
United States prices. Pro is an auto-renewing subscription, purchased and managed through Apple’s in-app purchase system and your Apple Account. There is no free trial. The price and billing period are shown in the app before you buy.
Payment is charged to your Apple Account. Subscriptions renew automatically unless canceled at least 24 hours before the end of the current period. Manage or cancel in your Apple Account settings.
Purchase questions? Contact support ↗Try the core workflow.
- Three successful superheat or subcooling calculations in total, not a monthly allowance
- PDF sharing from your successful calculation Results, within those three calculations
- Basic P-T reference
- Unit converter
- Common refrigerants list
- English and Spanish interface
Unlimited, with records.
- Unlimited calculations
- Saved Jobs: search, recalculate, Update Existing Job or Save as New Job
- Advanced P-T Reference: two-way lookup, full tables, refrigerant comparison
- PDF reports from saved job records, with job details and an optional company name
$5.99 per month or $49.99 per year (United States)
Field guides
The math behind the readings.
Short references with worked examples, written for technicians.
How to calculate superheat
The formula, where to measure, which saturation temperature to use, and a worked R-410A example.
How to calculate subcooling
The formula, which saturation temperature to use, and a worked R-410A example.
Reading a refrigerant P-T chart: bubble point, dew point and glide
Gauge pressure, bubble versus dew, glide on blends, and a short R-410A and R-454B excerpt.
Questions
Common questions.
Is HVAC Charge Pro on the App Store yet?
Yes. HVAC Charge Pro is available for iPhone on the App Store.
Does it work without a connection?
Yes for the core workflow. Calculations, the P-T reference, saved jobs and PDF generation run on the device. Purchasing, restoring Pro and opening support or legal links need internet.
Do I need an account?
No. The app asks for no account and no access to camera, photos, location, contacts or microphone.
How many calculations are free?
Three successful calculations in total. It is a one-time allowance, not a monthly one. Pro unlocks unlimited calculations.
Can I export a PDF without Pro?
Yes. Free users can share PDFs from their three successful calculation results: after a successful calculation, open Share Result on the Result screen and choose Share PDF Report. Once all three free calculations are used, a new calculation requires Pro. PDFs already saved to Files remain accessible. Saved Jobs, and PDF reports created from saved job records, require Pro.
How much does Pro cost?
In the United States, Pro is $5.99 per month or $49.99 per year. It is an auto-renewing subscription purchased and managed through Apple, and there is no free trial. The price and billing period are shown in the app before you buy.
Which refrigerants are supported?
R-22, R-32, R-134a, R-404A, R-407C, R-410A, R-448A, R-449A and R-454B.
Does it tell me the target superheat or subcooling?
No. It calculates the actual value from your readings. Use the manufacturer’s charging chart, data plate or service literature for the target.
Does it correct for altitude?
No. Pressure data uses a standard sea-level reference and applies no altitude correction.
Which devices does it run on?
iPhone with iOS 17 or later.
Engineering comes first
A reference aid.
Your judgment leads.
Superheat and subcooling values alone do not determine whether refrigerant should be added or removed.
Verify your instruments, selected units, refrigerant, and entered measurements. Follow equipment manufacturer instructions, approved service procedures, and applicable professional and safety requirements.
Read the Engineering Disclaimer ↗Your next field companion
Bring clarity to the job.
HVAC Charge Pro by MUEN Apps.
Professional tools. A focused workflow.