# HVAC Duct Sizer — HVAC duct sizing and more...

> HVAC duct sizing calculator for iPhone and iPad. (iPhone/iPad app by Carmel Software Corporation.)

- Source: https://appshunter.io/ios/app/hvac-duct-sizer/id317970395 (this page in markdown: same URL + `.md`)
- Developer: [Carmel Software Corporation](https://appshunter.io/developer/317970398)
- Category: Utilities, Business
- Price: $5.99 with in-app purchases
- Rating: 2.90/5 from 8 App Store ratings · 39 written reviews indexed
- Age rating: 4+
- Requires: iOS 15.6 · 17 MB
- Languages: American English
- Released: 2009-06-02
- Data updated: 2026-08-14
- Monetization: free with in-app purchases
- User reviews in markdown: https://appshunter.io/ios/app/hvac-duct-sizer/id317970395/reviews.md

## What is HVAC Duct Sizer?

The HVAC Duct Sizer app is the #1 selling duct sizing application for the Apple iPhone and iPad. Tens of thousands of happy users have downloaded this useful application for performing quick and simple duct sizing analysis. 

The HVAC Duct Sizer is a universal duct sizing app so that it works on both the iPhone and iPad and adjusts its screen size accordingly.

This app includes the HVAC Equipment Locator. Click here for details: http://bit.ly/1BPl1Nr

Just a couple of comments from our users:

"I'll be presenting your iPhone program to my HVAC class as an easy compact tool to have in hand when making sales and service calls." - R. Black

"I like this app and use it daily" - V. Joe

The Duct Sizer application allows you to quickly size one HVAC duct run or a range of duct sizes using the constant friction method. Think of this application as a digital version of the classic Trane Ductulator. 

In the "Size by Airflow" mode, you can specify the total airflow in CFM (or L/s), the aspect ratio and one of either the velocity of air or the friction loss per 100 feet (30 meters). The results include both the exact and rounded height and width (or diameter) dimensions and the calculated velocity and friction loss.

In the "Size by Dimensions" mode, you can analyze an existing duct system. There are options to input the existing duct dimensions and one of either the airflow or velocity values to derive the calculated duct friction loss.

In the "Range of Duct Sizes" mode, you can specify minimum and maximum friction loss and airflow values to display a range of duct sizes that fall in between the friction loss bounds.

You can specify additional parameters such as the duct shape (rectangular, round, or oval), the air temperature and the air pressure. You can also choose to display values in either English (IP) or Metric (SI) units.

This application uses slider controls that allow you to quickly increment or decrement the input values and immediately observe the calculated results. 

This app now works on your iPhone and iPad and adjusts its screen size accordingly.

Finally, you can email all of the inputs and results from all 3 input modes to perform further analysis using your desktop computer. The email includes HTML text and a .CSV attachment that can be imported into any popular spreadsheet.

The "HVAC Duct Sizer" application was designed by Carmel Software Corporation, a leader in HVAC design software since 1995. In fact, Autodesk (the makers of AutoCAD) acquired our load calculation software and incorporated it into their leading 3D modeling software called Revit. In addition, we developed a number of customized apps for ASHRAE, DNV GL, and other organizations.

This app now includes the HVAC Equipment Locator which allows you to keep track of all of your equipment and store it in the cloud. Click here for details: http://bit.ly/1yTq539

We also offer the following additional apps for the iPhone and iPad:

1. HVAC Residential Load Calcs for iPhone and iPad
2. HVAC Quick Load Plus
3. HVAC Quick Load
4. HVAC Toolkit
5. HVAC Pipe Sizer – Gas Low Pressure
6. HVAC Pipe Sizer - Gas High Pressure
7. HVAC Pipe Sizer – Liquid
8. HVAC Pipe Sizer – Steam
9. Steam Tables
10. Psychrometric Plus
11. Psychrometric LT
12. HVAC Pipe Sizer Plus
13. HVAC Pipe Sizer Gas Plus
14. HVAC Toolkit Ultimate
15. HVAC Equipment Locator
16. HVAC ResLoad-J
17. HVAC Psych HD

## Key features

- Duct sizing by airflow
- Duct sizing by dimensions
- Range of duct sizes calculation
- Rectangular, round, and oval duct shapes
- English and Metric unit options
- Email results with CSV attachment
- HVAC Equipment Locator

## Pricing and in-app purchases

Base price: $5.99.

**One-time purchases**

| Purchase | Price | Type |
| --- | --- | --- |
| HVAC Equipment Locator | $9.99 | one-time |


## Chart rankings

- #193 in Top Paid · Utilities (US App Store)

## Recent user reviews (10 of 39)

All indexed reviews: https://appshunter.io/ios/app/hvac-duct-sizer/id317970395/reviews.md

### 1/5 — ความคุ้มค่า

*2025-08-15, version 6.95*

ลองใช้แล้วไม่คุ้มเงิน ตั้งค่าอะไรไม่ได้เลย ยิ่งใช้งานยิ่งงง

### 5/5 — Great duct sizer

*2020-03-07*

I’m an HVAC engineer and I use this at work almost every day. It’s a great way to quickly size a run of duct and easily switch between duct types.

### 5/5 — A classic

*2014-08-13*

I’ve had this app for 4 or 5 years now, and I can’t believe how use it still is. It’s great that Carmel keeps updating it and now I can use it on my iPad.

### 4/5 — high quality accuracy.

*2014-07-15*

Very accurate and useful. Relatively easy to use if you know how to properly size ducts. The only problem with the app is after you enter a value, the screen stops scrolling up and down so you can't see the results. You have to back out to the main menu then re-select the category (i.e. Size by airflow) to see the answer.

### 1/5 — Worked before update

*2014-02-21, version 2.0*

Was a great app but now doesn't show top of screen after entering values. 
Sliders are impossible to set accurately too. They always move when your finger is lifted.

### 1/5 — Don't Waste Your Money

*2013-01-02, version 1.8*

You can get the same program by downloading the Johnstone Supply app for free.

### 5/5 — Mechanical Contractor

*2012-11-15*

Use this app professionally, easy to use, always on target!

### 5/5 — Poor quality app

*2012-11-15, version 1.8*

Not worth the money.

### 5/5 — Excellent

*2012-11-02*

This app is excellent tool for HVAC tech.  Thanks for help us.

### 5/5 — A classic

*2012-09-28*

This app has been around for years, and I finally got around to rating it. I use it daily and it's all i can ask for a simple duct sizing app. I love the emailing capability. Sure beats a ductulator. 

Love it!

## Frequently asked questions about HVAC Duct Sizer

### What does the HVAC Duct Sizer app do?

The HVAC Duct Sizer app is designed to perform quick and simple HVAC duct sizing analysis. It allows users to calculate necessary duct dimensions based on airflow requirements or existing duct dimensions. The app also offers a feature to determine a range of duct sizes within specified friction loss and airflow parameters.

### What are the key features of the HVAC Duct Sizer app?

Key features include sizing ducts by airflow or dimensions, calculating a range of duct sizes, supporting rectangular, round, and oval duct shapes, and offering both English (IP) and Metric (SI) units. Users can also email detailed results, including a .CSV attachment for further analysis, and access an HVAC Equipment Locator.

### How much does the HVAC Duct Sizer app cost?

The application is available for free with in-app purchases. While the core duct sizing functionality is accessible, additional features or advanced capabilities might be available through in-app purchases.

### What devices is the HVAC Duct Sizer app compatible with?

The HVAC Duct Sizer app is a universal application that works on both the Apple iPhone and iPad. It automatically adjusts its screen size to provide an optimal user experience on either device.

### Who would benefit from using the HVAC Duct Sizer app?

This app is ideal for HVAC professionals, technicians, and students who need a convenient tool for performing duct sizing calculations on the go. It's useful for sales and service calls, as well as for general HVAC design and analysis tasks.

## Version history (last 5 releases)

### 7.3 — 2026-02-16

1. Fixed crashing issue in Range of Duct Sizes form on iPad version.
2. Updated help.

### 7.1 — 2025-11-30

1. Added a Share button to the iPhone and iPad versions of the app, so you can now text, email, and download reports.
2. Updated help.

### 7.0 — 2025-10-28

1. Fixed issue with Global Settings form crashing on iPad with iOS 8.x or above.

### 6.95 — 2025-08-08

1. Added Share button to iPad version so user can share reports via email, text, or other means.

### 6.91 — 2025-05-20

1. Optimized for iOS 18.
2. Updated help

## Apps similar to HVAC Duct Sizer

| App | Rating | Price | Category |
| --- | --- | --- | --- |
| [Duct Calculator](https://appshunter.io/ios/app/duct-calculator/id1078238132) | 4.5 (188) | $19.99 | Utilities |
| [Bluon HVAC](https://appshunter.io/ios/app/bluon-hvac/id1357521880) | 4.8 (4,450) | Free | Utilities |
| [LGMV-Business](https://appshunter.io/ios/app/lgmv-business/id1506724643) | 2.1 (25) | Free | Utilities |
| [IN HVAC Calculator](https://appshunter.io/ios/app/in-hvac-calculator/id1219008229) | 4.2 (11) | Free | Utilities |
| [Digiduct](https://appshunter.io/ios/app/digiduct/id6738926359) | 4.6 (11) | Free | Utilities |
| [Duct Calculator Elite](https://appshunter.io/ios/app/duct-calculator-elite/id665701601) | 4.8 (231) | $9.99 | Utilities |

## More apps by Carmel Software Corporation

- [HVAC Pipe Sizer - Liquid](https://appshunter.io/ios/app/hvac-pipe-sizer-liquid/id325069065)
- [HVAC Pipe Sizer - Steam](https://appshunter.io/ios/app/hvac-pipe-sizer-steam/id336112747)
- [Steam Tables](https://appshunter.io/ios/app/steam-tables/id339948012)
- [HVAC Pipe Sizer - Gas Low](https://appshunter.io/ios/app/hvac-pipe-sizer-gas-low/id341688321)
- [HVAC Pipe Sizer - Gas High](https://appshunter.io/ios/app/hvac-pipe-sizer-gas-high/id341828523)

All apps by Carmel Software Corporation: https://appshunter.io/developer/317970398

## Related topics

[ductulator duct sizer](https://appshunter.io/ios/topics/ductulator-duct-sizer) · [hvac duct sizer](https://appshunter.io/ios/topics/hvac-duct-sizer) · [duct sizing](https://appshunter.io/ios/topics/duct-sizing) · [duct sizer](https://appshunter.io/ios/topics/duct-sizer) · [duct sizer calc hvac](https://appshunter.io/ios/topics/duct-sizer-calc-hvac) · [air duct size calculator](https://appshunter.io/ios/topics/air-duct-size-calculator) · [spiralite duct sizer](https://appshunter.io/ios/topics/spiralite-duct-sizer)

---

*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 2026-08-14.*