# BTU Calculator vs Digiduct

The clearest difference is in-app purchases: Digiduct at none against BTU Calculator's 1. Digiduct also leads on ads (none vs shown). BTU Calculator's advantage is ratings volume (318 vs 11) and iOS requirement (12.0 vs 26.2). On price, rating, update cadence and device support there is nothing between them.

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

On the App Store both sit at effectively the same score — 4.6 for BTU Calculator against 4.6 for Digiduct. That said, the two scores are not equally well evidenced: BTU Calculator has 318 ratings behind it against 11, so its average is the more settled of the two.

BTU Calculator ships an update every 4 months, Digiduct every 2 months. The most recent releases landed on October 22, 2026 and October 16, 2026 respectively.

## The numbers

| Metric | BTU Calculator | Digiduct |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [4.6 (318 ratings)](https://appshunter.io/ios/app/btu-calculator-data-centers/id685976218/reviews) | **[4.6 (11 ratings)](https://appshunter.io/ios/app/digiduct/id6738926359/reviews)** |
| Number of ratings | **318** | 11 |
| Positive reviews | 68.8% of reviews | — |
| In-app purchases | Yes | **No** |
| Ads | Yes | **No** |
| Update frequency | Every 4 months | **Every 2 months** |
| Monetization | Free with in-app purchases | **Ad-supported** |
| Size | 23 MB | 4 MB |
| Requires iOS | **12.0** | 26.2 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Cristinel Bontas](https://appshunter.io/developer/645866051) | [Syska Hennessy Group](https://appshunter.io/developer/1782943081) |

## What reviewers say

### BTU Calculator

[App page](https://appshunter.io/ios/app/btu-calculator-data-centers/id685976218)

Estimate the cooling capacity needed for your data center. This tool considers factors like space, occupants, and heat output to help you maintain optimal temperature and humidity. It provides instant results as you update inputs, serving as a guide for system selection.

**Highlights:** Estimate cooling capacity, Maintain 24°C and 30-50% humidity, Consider space, occupants, window R-value, Calculate total heat output, Instant cooling load results, Guide for system selection

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Remove Ads | $0.99 | one-time |


### Digiduct

[App page](https://appshunter.io/ios/app/digiduct/id6738926359)

This HVAC tool assists professionals with duct sizing calculations based on ASHRAE standards. It supports multiple duct shapes and offers intelligent features to ensure accurate and reliable designs for real-world scenarios.

**Highlights:** Duct sizing for rectangular, round, and flat oval ducts, Customizable dimensions with locked values, Duct location intelligence for context-aware sizing, Calculations based on CFM, pressure drop, or velocity, Alerts for exceeding pressure drop or velocity limits

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

**In-app purchases:** none


## Frequently asked questions

### Is BTU Calculator free?

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

### Is Digiduct free?

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

### Which has better reviews, BTU Calculator or Digiduct?

Digiduct is rated higher. BTU Calculator averages 4.6 out of 5 from 318 ratings, while Digiduct averages 4.6 from 11 ratings.

### Do BTU Calculator or Digiduct have ads?

BTU Calculator shows ads; Digiduct does not.

### Which is updated more often, BTU Calculator or Digiduct?

BTU Calculator ships an update every 4 months, and Digiduct every 2 months. Most recently, BTU Calculator was updated on October 22, 2026 and Digiduct on October 16, 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.*