# HVAC Master AI vs UnitDown AI

The clearest difference is update cadence: UnitDown AI at every 4 days against HVAC Master AI's every 11 days. On price, ads, in-app purchases and device support there is nothing between them.

Both are free to download. HVAC Master AI sells 1 in-app purchase, starting at $4.99 per month and UnitDown AI sells 2 in-app purchases, starting at $9.99 per month. Whichever you choose, the download price is not the number that matters.

HVAC Master AI ships an update every 11 days, UnitDown AI every 4 days. The most recent releases landed on October 16, 2026 and October 17, 2026 respectively.

## The numbers

| Metric | HVAC Master AI | UnitDown AI |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[5.0 (3 ratings)](https://appshunter.io/ios/app/hvac-master-ai/id6738960643/reviews)** | — |
| Number of ratings | **3** | — |
| Positive reviews | 100.0% of reviews | — |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | Every 11 days | **Every 4 days** |
| Monetization | Free with in-app purchases | — |
| Size | 159 MB | 8 MB |
| Requires iOS | 15.6 | **15.0** |
| Devices | iPhone, iPod | **iPhone, iPad, iPod** |
| Age rating | 17+ | 4+ |
| Developer | [alexis atilano](https://appshunter.io/developer/1783149667) | [JESUS ESCAMEA](https://appshunter.io/developer/1896505910) |

## What reviewers say

### HVAC Master AI

[App page](https://appshunter.io/ios/app/hvac-master-ai/id6738960643)

This mobile assistant helps HVAC technicians diagnose, repair, and optimize heating, ventilation, and air conditioning systems. It provides expert advice, refrigerant information, EPA 608 guidance, and heat pump insights for quick access to solutions.

**Highlights:** Comprehensive HVAC troubleshooting advice, Refrigerant expertise, EPA 608 compliance guidance, Heat pump system insights, Quick access to solutions

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Monthly  Subscription | $4.99 | per month |


### 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 HVAC Master AI free?

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

### Is UnitDown AI free?

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

### Do HVAC Master AI or UnitDown AI have ads?

Neither HVAC Master AI nor UnitDown AI shows ads.

### Which is updated more often, HVAC Master AI or UnitDown AI?

HVAC Master AI ships an update every 11 days, and UnitDown AI every 4 days. Most recently, HVAC Master AI was updated on October 16, 2026 and UnitDown AI on October 17, 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.*