# Psychro Chart vs Ductulator

Psychro Chart and Ductulator both sit at 4.8 stars, but that hides the real split: 50% of Ductulator's written reviews are positive against 0% of Psychro Chart's. Ductulator also leads on ratings volume (353 vs 6) and update cadence (every 2 months vs every 9 months). Psychro Chart's advantage is price (Free vs $3.99) and iOS requirement (7.0 vs 18.6). On rating, ads, in-app purchases and monetization model there is nothing between them.

Psychro Chart is free to download; Ductulator costs $3.99 up front. Neither carries in-app purchases, so what you see is what you pay.

On the App Store both sit at effectively the same score — 4.8 for Psychro Chart against 4.7 for Ductulator. That said, the two scores are not equally well evidenced: Ductulator has 353 ratings behind it against 6, so its average is the more settled of the two. Written reviews are what separate them: 0% of Psychro Chart's written reviews are positive against 50% of Ductulator's.

Psychro Chart ships an update every 9 months, Ductulator every 2 months. The most recent releases landed on October 24, 2026 and October 25, 2026 respectively.

## The numbers

| Metric | Psychro Chart | Ductulator |
| --- | --- | --- |
| Price | **Free** | $3.99 |
| Rating | **[4.8 (6 ratings)](https://appshunter.io/ios/app/psychro-chart/id1072047219/reviews)** | [4.7 (353 ratings)](https://appshunter.io/ios/app/ductulator-duct-sizing/id1474939475/reviews) |
| Number of ratings | 6 | **353** |
| Positive reviews | 0.0% of reviews | **50.0% of reviews** |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 9 months | **Every 2 months** |
| Monetization | Free | Free |
| Best chart rank | — | **#75** |
| Size | 27 MB | 1 MB |
| Requires iOS | **7.0** | 18.6 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Condair GmbH](https://appshunter.io/developer/903871077) | [Wassim Murr](https://appshunter.io/developer/1474939474) |

## What reviewers say

### Psychro Chart

[App page](https://appshunter.io/ios/app/psychro-chart/id1072047219)

This app simplifies complex air humidity calculations for humidification and heating needs. It allows for quick and accurate assessment of various scenarios using psychrometric or Mollier diagrams.

**Highlights:** Calculate air conditions, Determine humidification/heating needs, Perform psychrometric calculations, Use Mollier diagrams, Assess scenarios quickly

**Features:** macOS Compatibility

**In-app purchases:** none


### Ductulator

[App page](https://appshunter.io/ios/app/ductulator-duct-sizing/id1474939475)

**Currently charting:** #75 Top Paid · Productivity (US App Store)

Instantly calculate HVAC duct sizes based on airflow, friction rate, or velocity. This tool provides accurate duct dimensions in seconds without needing charts, supporting various duct types and units.

**Highlights:** Instant duct sizing, Friction rate or velocity calculation, Multiple valid duct dimensions, IP and SI units support, Detailed sizing mode, Rectangular, circular, and flexible ducts

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

**In-app purchases:** none

**What reviewers like**

- 👍 Very helpful for duct sizing
- 👍 Easy to use in the field
- 👍 Saves time
- 👍 Seamless imperial/metric transitions
- 👍 Excellent tool for duct design

**What reviewers complain about**

- 👎 App should be free
- 👎 Functionality is pointless for some needs
- 👎 Doesn't help with traditional residential HVAC duct sizing
- 👎 App is a scam
- 👎 Decimal point doesn't work

**Reported bugs**

- Decimal point doesn't work on calculator
- New flex option isn't working properly
- Friction rate can't be changed in the latest version
- Skips duct sizes (e.g., 24-26)

**Requested features**

- Ability to pick duct size and see CFM
- Include flat oval ducts
- Option to select round or square duct
- Ability to enter duct size and get CFM
- Option for flex duct


## Frequently asked questions

### Is Psychro Chart free?

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

### Is Ductulator free?

Ductulator costs $3.99, with no in-app purchases.

### Which has better reviews, Psychro Chart or Ductulator?

Psychro Chart is rated higher. Psychro Chart averages 4.8 out of 5 from 6 ratings, while Ductulator averages 4.7 from 353 ratings.

### Do Psychro Chart or Ductulator have ads?

Neither Psychro Chart nor Ductulator shows ads.

### Which is updated more often, Psychro Chart or Ductulator?

Psychro Chart ships an update every 9 months, and Ductulator every 2 months. Most recently, Psychro Chart was updated on October 24, 2026 and Ductulator on October 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.*