# Engineering Converter vs Duct Construction

The clearest difference is price: Engineering Converter at Free against Duct Construction's $0.99. Engineering Converter also leads on iOS requirement (15.0 vs 17.6). Duct Construction's advantage is ads (none vs shown) and update cadence (every 10 months vs every 42 months). On in-app purchases and device support there is nothing between them.

Engineering Converter is free to download; Duct Construction costs $0.99 up front. Neither carries in-app purchases, so what you see is what you pay.

Engineering Converter ships an update every 42 months, Duct Construction every 10 months. The most recent releases landed on September 12, 2026 and September 25, 2026 respectively.

## The numbers

| Metric | Engineering Converter | Duct Construction |
| --- | --- | --- |
| Price | **Free** | $0.99 |
| Rating | — | **[1.0 (1 ratings)](https://appshunter.io/ios/app/duct-construction/id6443518338/reviews)** |
| Number of ratings | — | **1** |
| Positive reviews | — | 0.0% of reviews |
| In-app purchases | No | No |
| Ads | Yes | **No** |
| Update frequency | Every 42 months | **Every 10 months** |
| Monetization | — | Paid |
| Best chart rank | — | **#184** |
| Size | 6 MB | 1 MB |
| Requires iOS | **15.0** | 17.6 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Brook Wallace](https://appshunter.io/developer/1234097174) | [Wassim Murr](https://appshunter.io/developer/1474939474) |

## What reviewers say

### Engineering Converter

[App page](https://appshunter.io/ios/app/engineering-converter/id1234097175)

**Features:** macOS Compatibility

**In-app purchases:** none


### Duct Construction

[App page](https://appshunter.io/ios/app/duct-construction/id6443518338)

**Currently charting:** #184 Top Paid · Productivity (US App Store)

This app helps determine duct construction and reinforcement options based on duct size and system pressure class. It provides condensed lists of suitable options, saving time spent on manual calculations and table lookups. Results are based on industry standards for galvanized steel duct sheets.

**Highlights:** Duct size range from 2" to 120", Pressure classes up to 4 in.wg, Calculates duct weights per linear foot, Determines required duct gauge and reinforcement spacing, Clear illustrations for reinforcement types, Simple and effective UI design

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

**In-app purchases:** none


## Frequently asked questions

### Is Engineering Converter free?

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

### Is Duct Construction free?

Duct Construction costs $0.99, with no in-app purchases.

### Do Engineering Converter or Duct Construction have ads?

Engineering Converter shows ads; Duct Construction does not.

### Which is updated more often, Engineering Converter or Duct Construction?

Engineering Converter ships an update every 42 months, and Duct Construction every 10 months. Most recently, Engineering Converter was updated on September 12, 2026 and Duct Construction on September 25, 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.*