# PolyPDF vs HVAC Duct Calculator

The clearest difference is in-app purchases: PolyPDF at none against HVAC Duct Calculator's 1. HVAC Duct Calculator's advantage is iOS requirement (15.0 vs 17.6). On price, ads and device support there is nothing between them.

Both are free to download. HVAC Duct Calculator sells 1 one-off in-app purchase. PolyPDF asks for nothing beyond the download.

## The numbers

| Metric | PolyPDF | HVAC Duct Calculator |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Weekly | — |
| Size | 3 MB | 8 MB |
| Requires iOS | 17.6 | **15.0** |
| Devices | iPhone, iPad | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [Mohammed Bala](https://appshunter.io/developer/955362555) | [MEP TASARIM MUHENDISLIK VE MUSAVIRLIK LIMITED SIRKETI](https://appshunter.io/developer/6780602473) |

## What reviewers say

### PolyPDF

[App page](https://appshunter.io/ios/app/polypdf/id6751167250)

**Features:** macOS Compatibility

**In-app purchases:** none


### HVAC Duct Calculator

[App page](https://appshunter.io/ios/app/hvac-duct-calculator/id6780602471)

**Features:** macOS Compatibility

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Lifetime VIP | $3.99 | one-time |


## Frequently asked questions

### Is PolyPDF free?

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

### Is HVAC Duct Calculator free?

HVAC Duct Calculator is free to download, with in-app purchases available.

### Do PolyPDF or HVAC Duct Calculator have ads?

Neither PolyPDF nor HVAC Duct Calculator shows ads.

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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.*