# RefCalc: Refrigerant PT Chart — Superheat & Subcooling Calc

> Superheat & Subcooling Calc (iPhone/iPad app by Duong Nguyen Huu.)

- Source: https://appshunter.io/ios/app/refcalc-refrigerant-pt-chart/id6793166788 (this page in markdown: same URL + `.md`)
- Developer: [Duong Nguyen Huu](https://appshunter.io/developer/1887479789)
- Category: Utilities, Productivity
- Price: $1.99
- Age rating: 4+
- Requires: iOS 16.4 · 31 MB
- Languages: American English
- Released: 2026-07-29
- Data updated: 2026-09-05
- User reviews in markdown: https://appshunter.io/ios/app/refcalc-refrigerant-pt-chart/id6793166788/reviews.md

## What is RefCalc?

RefCalc is the fast, offline Pressure–Temperature chart and Superheat/Subcooling calculator built for HVAC/R technicians — no subscription, no ads, one-time purchase.

CHECK CHARGE IN SECONDS
Enter suction pressure and suction line temperature to get instant superheat. Enter liquid line pressure and temperature to get instant subcooling. Color-coded results show at a glance whether you're in range.

FULL PT CHART, ANY REFRIGERANT
Type a pressure, get the saturation temperature. Type a temperature, get the saturation pressure. For blend refrigerants, RefCalc shows both bubble point and dew point plus the glide between them — the detail cheap PT apps get wrong.

BUILT-IN REFRIGERANTS
R-410A, R-32, R-454B, R-452B, R-22, R-134a, R-404A, R-407C, R-448A/R-449A, R-290, R-1234yf, R-513A — including the newer A2L mildly-flammable refrigerants (R-32, R-454B, R-452B) that older apps don't support.

WORKS YOUR WAY
• psi / bar / kPa / MPa
• Gauge (psig) or absolute (psia) reference
• °F or °C
• 7 languages: English, Spanish, Chinese, Portuguese, Japanese, Korean, Vietnamese

100% OFFLINE
No account, no internet permission, no analytics, no ads. Your data stays on your device. Buy once, use forever.

Refrigerant data sourced from NIST REFPROP and manufacturer/ASHRAE published PT charts. RefCalc provides the math — always confirm final charge against the equipment nameplate or OEM charging chart.


## Version history (last 1 release)

### 1.0 — 2026-07-30

No release notes.

## More apps by Duong Nguyen Huu

- [Tích Sản: Giá Vàng & Tài Sản](https://appshunter.io/ios/app/tich-san-gia-vang-and-tai-san/id6761044270)
- [PDFScan Go](https://appshunter.io/ios/app/pdfscan-go/id6761462436)
- [AirCalc Psychrometric](https://appshunter.io/ios/app/aircalc-psychrometric/id6762062746)
- [Daily Health Reminder App](https://appshunter.io/ios/app/daily-health-reminder-app/id6762444133)
- [Meno: Perimenopause Tracker](https://appshunter.io/ios/app/meno-perimenopause-tracker/id6762710155)
- [Barber Việt Nam](https://appshunter.io/ios/app/barber-viet-nam/id6763964976)

All apps by Duong Nguyen Huu: https://appshunter.io/developer/1887479789

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*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 2026-09-05.*