# Digiduct vs HVACsim

The clearest difference is rating: Digiduct at 4.6 against HVACsim's 2.6. Digiduct also leads on in-app purchases (none vs 1). HVACsim's advantage is iOS requirement (13.4 vs 26.2). On price, ratings volume, update cadence and ads there is nothing between them.

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

Digiduct holds the better App Store score, 4.6 against 2.6. Both are backed by a comparable volume of ratings — 11 and 10 respectively.

Both ship on a similar rhythm, roughly every 2 months. The most recent releases landed on September 12, 2026 and September 20, 2026 respectively.

## The numbers

| Metric | Digiduct | HVACsim |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.6 (11 ratings)](https://appshunter.io/ios/app/digiduct/id6738926359/reviews)** | [2.6 (10 ratings)](https://appshunter.io/ios/app/hvacsim/id6740935191/reviews) |
| Number of ratings | **11** | 10 |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 2 months | Every 2 months |
| Monetization | **Ad-supported** | Free with in-app purchases |
| Size | 4 MB | 20 MB |
| Requires iOS | 26.2 | **13.4** |
| Devices | iPhone, iPad | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Syska Hennessy Group](https://appshunter.io/developer/1782943081) | [Nauman Innovation Group LLC](https://appshunter.io/developer/1764933586) |

## What reviewers say

### 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


### HVACsim

[App page](https://appshunter.io/ios/app/hvacsim/id6740935191)

This app offers interactive learning and real-world data analysis to help HVAC professionals diagnose and troubleshoot systems. It provides personalized training plans, skill assessments, and team management tools for contractors.

**Highlights:** Technical Knowledge Evaluator, Individualized Learning Plans, Real-World Data Analysis, Team Management Tools, Continuous Learning Library

**Features:** macOS Compatibility

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Full Access | $29.99 | one-time |


## Frequently asked questions

### Is Digiduct free?

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

### Is HVACsim free?

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

### Which has better reviews, Digiduct or HVACsim?

Digiduct is rated higher. Digiduct averages 4.6 out of 5 from 11 ratings, while HVACsim averages 2.6 from 10 ratings.

### Do Digiduct or HVACsim have ads?

Neither Digiduct nor HVACsim shows ads.

### Which is updated more often, Digiduct or HVACsim?

Digiduct ships an update every 2 months, and HVACsim every 2 months. Most recently, Digiduct was updated on September 12, 2026 and HVACsim on September 20, 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.*