HVAC Duct Sizer vs Bluon HVAC
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
HVAC Duct Sizer
This app provides quick and simple HVAC duct sizing analysis. It allows users to calculate duct dimensions based on airflow or existing dimensions, and can also determine a range of duct sizes. Results can be emailed for further analysis.
- 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
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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. 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. 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 a PDF report, 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. 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
Bluon HVAC
Access a vast database of HVAC-R and plumbing unit documentation, including specs, manuals, and replacement parts. Get AI-powered troubleshooting and connect with live veteran technicians for support.
- 35,000,000+ HVAC unit database
- Model specs, age, and warranty info
- Original parts and replacement options
- AI-powered troubleshooting (Master Mechanic)
- Live veteran technician support line
- Supplier contact and ordering
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Bluon provides the technical information and support to tackle any job in HVAC-R and plumbing. Scan or search for any unit to find the documentation on over 35,000,000+ HVAC models across virtual every brand. Instantly access the key model specs, age/warranty, manuals, original parts, part specs, and replacement options. See which suppliers carry which part - you can even text/email them or order directly through their website. Get detailed troubleshooting guidance from MasterMechanic, our custom A.l. built with the database and with the problem/solution knowledge of over 135,000 live support calls, or call our Live Tech Support line to connect to our team of 25+ year veteran technicians. Bluon has your back. App Features Include: - Database of 35,000,000+ HVAC units (manuals, specs and part lists) - Master Mechanic: leading A.I. tool for techs - Live Support line: talk to REAL veteran techs to solve problems in the field!
Screenshots
Verdict
The clearest difference is price: Bluon HVAC at Free against HVAC Duct Sizer's $4.99. Bluon HVAC also leads on rating (4.8 vs 3.1) and in-app purchases (none vs 1). HVAC Duct Sizer's advantage is ads (none vs shown). On review sentiment and device support there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
Bluon HVAC is free to download; HVAC Duct Sizer costs $4.99 up front. HVAC Duct Sizer sells 1 one-off in-app purchase. Bluon HVAC asks for nothing beyond the download.
Bluon HVAC holds the better App Store score, 4.8 against 3.1. That said, the two scores are not equally well evidenced: Bluon HVAC has 4.5K ratings behind it against 9, so its average is the more settled of the two. Written reviews complicate that: 63% of HVAC Duct Sizer's written reviews are positive against 55% of Bluon HVAC's, so the app with the better star average is not the one people write more warmly about.
HVAC Duct Sizer ships an update every 3 months, Bluon HVAC monthly. The most recent releases landed on October 31, 2026 and November 6, 2026 respectively.
| Parameter | HVAC Duct Sizer | Bluon HVAC |
|---|---|---|
| Price | $4.99 | Free — better |
| Rating | 3.1 (9 ratings) | 4.8 (4.5K ratings) — better |
| Positive reviews | 62.5% of reviews — better | 54.6% of reviews |
| Number of ratings | 9 | 4.5K — better |
| Update frequency | Every 3 months | Monthly — better |
| Ads | No — better | Yes |
| In-app purchases | Yes | No — better |
| Monetization | Free with in-app purchases | Ad-supported — better |
| Devices | iPhone, iPad | iPhone, iPad, iPod — better |
| Requires iOS | 17.0 | 15.1 — better |
| Further details — not scored | ||
| Size | 1 MB | 170 MB |
| Age rating | +4 | 4+ |
| Developer | Carmel Software Corporation | Bluon, Inc. |
Customer experience
HVAC Duct Sizer
Bluon HVAC
Bugs and requests
HVAC Duct Sizer
Not enough reviews yet to summarise bugs or requests.
Bluon HVAC
Reported bugs
2 issues- Login/password reset issues
- Frequent crashes or loading problems
Requested features
3 requests- Individual technician subscription option
- More comprehensive coverage of HVAC equipment models
- Ability to access full manuals without restrictions
In-app purchases
HVAC Duct Sizer
- HVAC Equipment Locator$9.99
Bluon HVAC
No in-app purchases
Questions
Is HVAC Duct Sizer free?
Is Bluon HVAC free?
Which has better reviews, HVAC Duct Sizer or Bluon HVAC?
Do HVAC Duct Sizer or Bluon HVAC have ads?
Which is updated more often, HVAC Duct Sizer or Bluon HVAC?
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