# RefrigCharge — HVAC Refrigerant Calculator

> HVAC Refrigerant Calculator (iPhone/iPad app by Shanghai Sheyuan Network Technology Co., Ltd..)

- Source: https://appshunter.io/ios/app/refrigcharge/id6761541500 (this page in markdown: same URL + `.md`)
- Developer: [Shanghai Sheyuan Network Technology Co., Ltd.](https://appshunter.io/developer/1560626858)
- Category: Utilities
- Price: $4.99
- Age rating: 4+
- Requires: iOS 17.0 · 1 MB
- Languages: English
- Released: 2026-04-04
- Data updated: 2026-07-08
- User reviews in markdown: https://appshunter.io/ios/app/refrigcharge/id6761541500/reviews.md

## What is RefrigCharge?

Built for HVAC service techs and install crews who need subcool / superheat diagnosis on the roof - not a dashboard you log into.

WHAT IT DOES
Computes measured subcooling and superheat from your gauge readings, compares them against per-refrigerant target windows, and tells you whether the system is undercharged, overcharged, or showing airflow issues. Charge adjustment advice differs for TXV vs. piston / cap-tube metering, matching the field workflow.

REFRIGERANTS SUPPORTED
- R-410A
- R-22
- R-134a
- R-404A
- R-407C

INPUTS
- Refrigerant type (picker)
- Metering device (TXV or Piston / Cap Tube)
- Liquid line temperature
- Condensing saturation temperature
- Suction line temperature
- Evaporating saturation temperature
- °F or °C toggle

RETURNS
- Measured subcooling vs. target (color-coded: green within ±3°F, red outside)
- Measured superheat vs. target (color-coded)
- Diagnosis: undercharged, overcharged, normal, or airflow issue
- Charge adjustment advice: ADD, REMOVE, or CORRECT
- Adjustment basis: subcool for TXV, superheat for piston

WHY THIS APP, NOT THE FREE ONES
- Math is shown - measured minus target, with the per-refrigerant windows visible.
- Status at a glance - color-coded so you do not have to do mental arithmetic on the ladder.
- Works offline - RF-shielded basements, attics, and roofs. Always available.
- No login. No ads. No telemetry. No subscription.

PRICING
$4.99. Pay once, own it. Lifetime access on iPhone, iPad, and Mac via Family Sharing.

NOT A SUBSTITUTE FOR
The manufacturer's charging procedure for your specific equipment. The equipment data plate's nameplate charge. Calibrated gauge sets. This app gives you a directional read - verify against the OEM service manual before adjusting.


## Version history (last 3 releases)

### 1.0.3 — 2026-07-01

Added R-32 and R-454B (A2L low-GWP) refrigerant support for 2026 system charging.

### 1.0.1 — 2026-04-29

Listing refresh - clarified the description, inputs/outputs, and which standards are referenced. No functional changes.

### 1.0 — 2026-04-04

No release notes.

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All apps by Shanghai Sheyuan Network Technology Co., Ltd.: https://appshunter.io/developer/1560626858

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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 2026-07-08.*