# CaptiveAire Toolbox vs UnitDown AI

The clearest difference is in-app purchases: CaptiveAire Toolbox at none against UnitDown AI's 2. On price, update cadence, ads and device support there is nothing between them.

Both are free to download. UnitDown AI sells 2 in-app purchases, starting at $9.99 per month. CaptiveAire Toolbox asks for nothing beyond the download.

CaptiveAire Toolbox ships an update every 6 days, UnitDown AI every 4 days. The most recent releases landed on October 5, 2026 and October 17, 2026 respectively.

## The numbers

| Metric | CaptiveAire Toolbox | UnitDown AI |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[5.0 (1 ratings)](https://appshunter.io/ios/app/captiveaire-toolbox/id6765656560/reviews)** | — |
| Number of ratings | **1** | — |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 6 days | **Every 4 days** |
| Monetization | Free | — |
| Size | 71 MB | 8 MB |
| Requires iOS | 16.0 | **15.0** |
| Devices | iPhone, iPad | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [CaptiveAire Systems, Inc.](https://appshunter.io/developer/1896026735) | [JESUS ESCAMEA](https://appshunter.io/developer/1896505910) |

## What reviewers say

### CaptiveAire Toolbox

[App page](https://appshunter.io/ios/app/captiveaire-toolbox/id6765656560)

This app provides over 40 HVAC and building-systems engineering calculators. It's designed for field use, offering standard industry formulas for cooling, heating, ventilation, electrical sizing, and more. Access detailed formula definitions and reference data.

**Highlights:** 40+ HVAC engineering calculators, Cooling and heating load calculations, Ventilation and airflow tools, Electrical sizing and motor circuits, Duct and piping pressure drop, Reference data and psychrometric chart

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

**In-app purchases:** none


### UnitDown AI

[App page](https://appshunter.io/ios/app/unitdown-ai/id6767750626)

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

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| UnitDown Pro Monthly | $9.99 | per month |
| UnitDown Pro Annual | $149.00 | per year |


## Frequently asked questions

### Is CaptiveAire Toolbox free?

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

### Is UnitDown AI free?

UnitDown AI is free to download, with in-app purchases available.

### Do CaptiveAire Toolbox or UnitDown AI have ads?

Neither CaptiveAire Toolbox nor UnitDown AI shows ads.

### Which is updated more often, CaptiveAire Toolbox or UnitDown AI?

CaptiveAire Toolbox ships an update every 6 days, and UnitDown AI every 4 days. Most recently, CaptiveAire Toolbox was updated on October 5, 2026 and UnitDown AI on October 17, 2026.

---

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