# Q vs Engineering Calculator HVAC

The clearest difference is in-app purchases: Engineering Calculator HVAC at none against Q's 3. Engineering Calculator HVAC also leads on device support (3 vs 1) and iOS requirement (15.0 vs 26.0). Q's advantage is update cadence (every 2 months vs every 6 months). On price and ads there is nothing between them.

Both are free to download. Q sells 3 one-off in-app purchases. Engineering Calculator HVAC asks for nothing beyond the download.

Q ships an update every 2 months, Engineering Calculator HVAC every 6 months. The most recent releases landed on October 7, 2026 and October 28, 2026 respectively.

## The numbers

| Metric | Q | Engineering Calculator HVAC |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | **Every 2 months** | Every 6 months |
| Size | 39 MB | 19 MB |
| Requires iOS | 26.0 | **15.0** |
| Devices | iPhone | **iPhone, iPad, iPod** |
| Age rating | 17+ | 4+ |
| Developer | [Aernoud Dekker](https://appshunter.io/developer/1772623159) | [aleksandr bronnikov](https://appshunter.io/developer/1885003900) |

## What reviewers say

### Q

[App page](https://appshunter.io/ios/app/q-ledger/id6754329231)

**Features:** macOS Compatibility

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| 5 Wallet Bundle (Pro Discount) | $2.99 | one-time |
| 5 Wallet Bundle | $3.99 | one-time |
| Q-Ledger Pro | $7.99 | one-time |


### Engineering Calculator HVAC

[App page](https://appshunter.io/ios/app/engineering-calculator-hvac/id6760564633)

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

**In-app purchases:** none


## Frequently asked questions

### Is Q free?

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

### Is Engineering Calculator HVAC free?

Engineering Calculator HVAC is free to download, with no in-app purchases.

### Do Q or Engineering Calculator HVAC have ads?

Neither Q nor Engineering Calculator HVAC shows ads.

### Which is updated more often, Q or Engineering Calculator HVAC?

Q ships an update every 2 months, and Engineering Calculator HVAC every 6 months. Most recently, Q was updated on October 7, 2026 and Engineering Calculator HVAC on October 28, 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.*