Comparison

HVAC Duct Sizer vs Pipe Sizer

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

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.

Highlights
  • 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
Features
Read full description

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

About

Pipe Sizer

This utility app assists in selecting appropriate pipe diameters for water systems, supporting both pressure and gravity flow calculations. It offers automatic recommendations based on user-defined limits and incorporates multiple pipe materials and unit systems.

Highlights
  • Pressure pipe sizing
  • Gravity pipe sizing
  • Automatic pipe size recommendations
  • Multiple pipe material support
  • SI and Imperial units
  • Hazen-Williams and Manning equations
Features
Read full description

PipeSizer helps you quickly choose the right pipe diameter for water systems — for both pressure and gravity flow. PRESSURE PIPE SIZING • Size pipes from a target flow rate. • Set your maximum friction rate and velocity limits. • Calculations based on the Hazen-Williams equation. GRAVITY PIPE SIZING • Size pipes from a target flow rate. • Evaluate flow capacity and velocity under gravity conditions. • Calculations based on the Manning equation. KEY FEATURES • Automatic recommended pipe size based on your limits. • Multiple pipe materials with built-in coefficients (more added over time). • Works in both SI and Imperial (I-P) units. • Designed for engineers, plumbers, and irrigation/drainage design workflows. Feedback is welcome — it directly shapes upcoming updates.

Screenshots

HVAC Duct Sizer4 screens
Pipe Sizer4 screens

Verdict

The call

The clearest difference is rating: Pipe Sizer at 5.0 against HVAC Duct Sizer's 3.1. Pipe Sizer also leads on review sentiment (100% vs 63%) and in-app purchases (none vs 1). HVAC Duct Sizer's advantage is update cadence (every 3 months vs every 27 months) and ratings volume (9 vs 3). On ads, device support and iOS requirement 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

CostPrice · In-app purchases · Ads · Monetization

HVAC Duct Sizer costs $4.99 and Pipe Sizer $0.99 up front. HVAC Duct Sizer sells 1 one-off in-app purchase. Pipe Sizer asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

Pipe Sizer holds the better App Store score, 5.0 against 3.1. Both are backed by a comparable volume of ratings — 9 and 3 respectively. Written reviews point the same way: 63% of HVAC Duct Sizer's written reviews are positive against 100% of Pipe Sizer's.

UpkeepUpdate frequency

HVAC Duct Sizer ships an update every 3 months, Pipe Sizer every 27 months. The most recent releases landed on October 31, 2026 and November 3, 2026 respectively.

Scorecard7 real differences · 3 level
HVAC Duct Sizer versus Pipe Sizer: the parameters behind the verdict, then further details
ParameterHVAC Duct SizerPipe Sizer
Price$4.99$0.99 — better
Rating3.1 (9 ratings)5.0 (3 ratings) — better
Positive reviews62.5% of reviews100.0% of reviews — better
Number of ratings9 — better3
Update frequencyEvery 3 months — betterEvery 27 months
AdsNoNo
In-app purchasesYesNo — better
MonetizationFree with in-app purchases — betterPaid
DevicesiPhone, iPadiPhone, iPad
Requires iOS17.0 — better17.6
Further details — not scored
Size1 MB1 MB
Age rating+44+
DeveloperCarmel Software CorporationWassim Murr

Customer experience

HVAC Duct Sizer

All ratings9 ratings
Positive44.4%
Neutral11.1%
Negative44.4%
Written reviews40 reviews
Positive62.5%
Neutral5.0%
Negative32.5%

Pipe Sizer

All ratings3 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews2 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

In-app purchases

1 purchases

HVAC Duct Sizer

One-time1
  • HVAC Equipment Locator$9.99
None

Pipe Sizer

No in-app purchases

Questions

Is HVAC Duct Sizer free?
HVAC Duct Sizer costs $4.99, and also offers in-app purchases.
Is Pipe Sizer free?
Pipe Sizer costs $0.99, with no in-app purchases.
Which has better reviews, HVAC Duct Sizer or Pipe Sizer?
Pipe Sizer is rated higher. HVAC Duct Sizer averages 3.1 out of 5 from 9 ratings, while Pipe Sizer averages 5.0 from 3 ratings.
Do HVAC Duct Sizer or Pipe Sizer have ads?
Neither HVAC Duct Sizer nor Pipe Sizer shows ads.
Which is updated more often, HVAC Duct Sizer or Pipe Sizer?
HVAC Duct Sizer ships an update every 3 months, and Pipe Sizer every 27 months. Most recently, HVAC Duct Sizer was updated on October 31, 2026 and Pipe Sizer on November 3, 2026.

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