# HVAC RefCharge vs ASHRAE Psychrometric Chart

The clearest difference is price: HVAC RefCharge at $9.99 against ASHRAE Psychrometric Chart's $19.99. ASHRAE Psychrometric Chart's advantage is in-app purchases (none vs 1) and iOS requirement (13.0 vs 17.0). On review sentiment, update cadence, ads and monetization model there is nothing between them.

HVAC RefCharge costs $9.99 and ASHRAE Psychrometric Chart $19.99 up front. HVAC RefCharge sells 1 one-off in-app purchase. ASHRAE Psychrometric Chart asks for nothing beyond the download.

Both ship on a similar rhythm, roughly every 11 months. The most recent releases landed on October 27, 2026 and October 12, 2026 respectively.

## The numbers

| Metric | HVAC RefCharge | ASHRAE Psychrometric Chart |
| --- | --- | --- |
| Price | **$9.99** | $19.99 |
| Positive reviews | **33.3% of reviews** | 27.3% of reviews |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | Every 11 months | Every 11 months |
| Monetization | Paid | Paid |
| Size | 6 MB | 2 MB |
| Requires iOS | 17.0 | **13.0** |
| Devices | **iPhone, iPad** | iPad |
| Age rating | +4 | 4+ |
| Developer | [Carmel Software Corporation](https://appshunter.io/developer/317970398) | [ASHRAE, Inc.](https://appshunter.io/developer/375374912) |

## What reviewers say

### HVAC RefCharge

[App page](https://appshunter.io/ios/app/hvac-refcharge/id577005428)

This app helps HVAC technicians quickly calculate refrigerant superheat and subcool levels. It supports over 100 refrigerants and offers interactive adjustments for precise charging decisions. Features include atmospheric pressure adjustments and unit customization.

**Highlights:** Superheat and subcool calculations, Supports 100+ refrigerants, Interactive slider for adjustments, Atmospheric pressure compensation, Customizable input types, Project photo assignment, Email report generation, English/Metric unit display

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| HVAC Equipment Locator | $9.99 | one-time |


### ASHRAE Psychrometric Chart

[App page](https://appshunter.io/ios/app/ashrae-psychrometric-chart/id584295008)

This interactive tool allows users to plot and customize psychrometric charts on their iPad. Easily create and save HVAC process graphs, update properties dynamically, and share charts and data via email. Supports both IP and SI units.

**Highlights:** Interactive psychrometric chart plotting, Customizable chart appearance, Dynamic property updates, Create and edit points and labels, Email charts and data, Unlimited projects and templates, Zoom and pinch functionality

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is HVAC RefCharge free?

HVAC RefCharge costs $9.99, and also offers in-app purchases.

### Is ASHRAE Psychrometric Chart free?

ASHRAE Psychrometric Chart costs $19.99, with no in-app purchases.

### Do HVAC RefCharge or ASHRAE Psychrometric Chart have ads?

Neither HVAC RefCharge nor ASHRAE Psychrometric Chart shows ads.

### Which is updated more often, HVAC RefCharge or ASHRAE Psychrometric Chart?

HVAC RefCharge ships an update every 11 months, and ASHRAE Psychrometric Chart every 11 months. Most recently, HVAC RefCharge was updated on October 27, 2026 and ASHRAE Psychrometric Chart on October 12, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*