# BOHN vs Duct Calculator.

The clearest difference is in-app purchases: BOHN at none against Duct Calculator.'s 1. BOHN also leads on rating (5.0 vs 4.7) and update cadence (every 3 months vs every 10 months). Duct Calculator.'s advantage is ratings volume (3 vs 1). On price, ads and device support there is nothing between them.

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

BOHN holds the better App Store score, 5.0 against 4.7. Both are backed by a comparable volume of ratings — 1 and 3 respectively.

BOHN ships an update every 3 months, Duct Calculator. every 10 months. The most recent releases landed on October 7, 2026 and October 12, 2026 respectively.

## The numbers

| Metric | BOHN | Duct Calculator. |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[5.0 (1 ratings)](https://appshunter.io/ios/app/bohn/id735544893/reviews)** | [4.7 (3 ratings)](https://appshunter.io/ios/app/duct-calculator/id6756908372/reviews) |
| Number of ratings | 1 | **3** |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | **Every 3 months** | Every 10 months |
| Monetization | **Free** | Free with in-app purchases |
| Size | 15 MB | 44 MB |
| Requires iOS | **12.1** | 15.6 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [armando monroy](https://appshunter.io/developer/735544896) | [Sachinbhai Surani](https://appshunter.io/developer/1838685550) |

## What reviewers say

### BOHN

[App page](https://appshunter.io/ios/app/bohn/id735544893)

This app provides a comprehensive catalog of refrigeration products, featuring technical specifications, pricing, and catalogs. Users can perform quick equipment calculations for specific applications and share them. Direct contact with the company is available through email or the app's web page.

**Highlights:** Product catalog access, Technical specifications, Pricing information, Equipment calculation tool, Direct contact options, Improved search functionality

**Features:** macOS Compatibility

**In-app purchases:** none


### Duct Calculator.

[App page](https://appshunter.io/ios/app/duct-calculator/id6756908372)

This professional HVAC utility assists engineers and technicians with precise duct sizing and airflow calculations for ventilation systems. It simplifies essential calculations for both design and installation work, improving on-site efficiency.

**Highlights:** Calculate duct sizes using airflow (CFM) and velocity (FPM), Supports rectangular and round duct sizing in inches, Determine air flow rate in CFM, Calculate air velocity in FPM, Simple interface for fast on-site calculations

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Lifetime premium | $9.99 | one-time |


## Frequently asked questions

### Is BOHN free?

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

### Is Duct Calculator. free?

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

### Which has better reviews, BOHN or Duct Calculator.?

BOHN is rated higher. BOHN averages 5.0 out of 5 from 1 ratings, while Duct Calculator. averages 4.7 from 3 ratings.

### Do BOHN or Duct Calculator. have ads?

Neither BOHN nor Duct Calculator. shows ads.

### Which is updated more often, BOHN or Duct Calculator.?

BOHN ships an update every 3 months, and Duct Calculator. every 10 months. Most recently, BOHN was updated on October 7, 2026 and Duct Calculator. on October 12, 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.*