# DuctChecker vs PVVS

The clearest difference is price: PVVS at Free against DuctChecker's $6.99. DuctChecker's advantage is ads (none vs shown). On update cadence, in-app purchases, device support and iOS requirement there is nothing between them.

PVVS is free to download; DuctChecker costs $6.99 up front. Neither carries in-app purchases, so what you see is what you pay.

DuctChecker ships an update every 4 months, PVVS every 2 months. The most recent releases landed on September 7, 2026 and September 8, 2026 respectively.

## The numbers

| Metric | DuctChecker | PVVS |
| --- | --- | --- |
| Price | $6.99 | **Free** |
| Positive reviews | 0.0% of reviews | — |
| In-app purchases | No | No |
| Ads | **No** | Yes |
| Update frequency | Every 4 months | **Every 2 months** |
| Monetization | Paid | — |
| Size | 23 MB | 7 MB |
| Requires iOS | 15.0 | 15.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [AIR DESIGN, INC.](https://appshunter.io/developer/923430781) | [sigeyosi kanenishi](https://appshunter.io/developer/629958778) |

## What reviewers say

### DuctChecker

[App page](https://appshunter.io/ios/app/ductchecker/id933593987)

Easily calculate duct dimensions using various engineering methods like constant pressure, static pressure regain, total pressure, and velocity. This tool simplifies complex duct design calculations, typically found in flow diagrams or slide rules.

**Highlights:** Constant pressure method calculation, Static pressure regain method, Total pressure method, Velocity method, Duct dimension determination, Simplified duct design

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

**In-app purchases:** none


### PVVS

[App page](https://appshunter.io/ios/app/pvvs/id1476646663)

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is DuctChecker free?

DuctChecker costs $6.99, with no in-app purchases.

### Is PVVS free?

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

### Do DuctChecker or PVVS have ads?

PVVS shows ads; DuctChecker does not.

### Which is updated more often, DuctChecker or PVVS?

DuctChecker ships an update every 4 months, and PVVS every 2 months. Most recently, DuctChecker was updated on September 7, 2026 and PVVS on September 8, 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.*