# airTool vs h,x Calculator

The clearest difference is iOS requirement: h,x Calculator at 7.0 against airTool's 15.6. On price, update cadence, ads and in-app purchases there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

Both ship on a similar rhythm, roughly every 4 months. The most recent releases landed on October 14, 2026 and October 11, 2026 respectively.

## The numbers

| Metric | airTool | h,x Calculator |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 4 months | Every 4 months |
| Monetization | — | Free |
| Size | 17 MB | 27 MB |
| Requires iOS | 15.6 | **7.0** |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [maennchen1.de <Roger Rehnelt>](https://appshunter.io/developer/460800416) | [Condair GmbH](https://appshunter.io/developer/903871077) |

## What reviewers say

### airTool

[App page](https://appshunter.io/ios/app/airtool/id463173545)

**Features:** macOS Compatibility

**In-app purchases:** none


### h,x Calculator

[App page](https://appshunter.io/ios/app/hx-calculator/id903871074)

This software calculates air condition changes during adiabatic or isothermal humidification processes. It determines air states before and after humidification, humidification power, and heating power. The app supports both metric and imperial units.

**Highlights:** Calculate air condition changes, Determine humidification power, Calculate heating power, Generate h,x diagram, Metric and imperial unit support

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is airTool free?

airTool is free to download, with no in-app purchases.

### Is h,x Calculator free?

h,x Calculator is free to download, with no in-app purchases.

### Do airTool or h,x Calculator have ads?

Neither airTool nor h,x Calculator shows ads.

### Which is updated more often, airTool or h,x Calculator?

airTool ships an update every 4 months, and h,x Calculator every 4 months. Most recently, airTool was updated on October 14, 2026 and h,x Calculator on October 11, 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.*