# DuctWheel - HVAC Duct Sizer — Round & Rectangular Sizing

> Round & Rectangular Sizing (iPhone/iPad app by Yoshifumi Sato.)

- Source: https://appshunter.io/ios/app/ductwheel-hvac-duct-sizer/id6796186947 (this page in markdown: same URL + `.md`)
- Developer: [Yoshifumi Sato](https://appshunter.io/developer/6780413827)
- Category: Utilities
- Price: $3.99
- Age rating: 4+
- Requires: iOS 17.0 · 1 MB
- Languages: American English
- Released: 2026-08-04
- Data updated: 2026-08-07
- User reviews in markdown: https://appshunter.io/ios/app/ductwheel-hvac-duct-sizer/id6796186947/reviews.md

## What is DuctWheel?

DuctWheel sizes HVAC ductwork the way a mechanical designer would — by solving the actual duct friction physics, not by eyeballing a chart.

Enter your airflow (CFM) and a target friction rate, and DuctWheel solves for the round duct diameter using the Darcy-Weisbach equation with a Swamee-Jain friction-factor approximation (the same physics behind the SMACNA/ASHRAE duct friction charts). Need a rectangular duct instead? Convert between round and rectangular sizes using the standard ASHRAE equal-friction equivalent-diameter formula, in either direction.

Why DuctWheel:
- Real duct physics (Darcy-Weisbach + Swamee-Jain), not a static lookup chart
- Round-to-rectangular and rectangular-to-round conversion
- Galvanized and flex duct roughness presets, or enter your own
- Velocity flagged automatically when it's high enough to cause noise
- Save calculations to compare runs and jobs
- Works completely offline - no account, no ads

Reference tool note: this app is a design aid using standard published duct-friction methodology. Always check results against your project specs, local code, or a licensed mechanical engineer for anything code-critical.

One-time purchase, no subscription. No data collected.


## Version history (last 1 release)

### 1.0 — 2026-08-04

No release notes.

## More apps by Yoshifumi Sato

- [おけいこ月謝帳 教室の集金管理](https://appshunter.io/ios/app/id6787108752)
- [DualShot: Front & Back Cam](https://appshunter.io/ios/app/dualshot-front-and-back-cam/id6788761561)
- [Progressly – Body Progress](https://appshunter.io/ios/app/progressly-body-progress/id6789591055)
- [Holdly – Isometric Timer](https://appshunter.io/ios/app/holdly-isometric-timer/id6789790139)
- [かんじ1年生 小学1年の漢字ドリル](https://appshunter.io/ios/app/1-1/id6789917332)
- [かんじ3年生 小学3年の漢字ドリル](https://appshunter.io/ios/app/3-3/id6790055787)

All apps by Yoshifumi Sato: https://appshunter.io/developer/6780413827

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-08-07.*