# HVAC Pipe Sizer - Gas Plus — High/Low press. gas pipe calcs

> HVAC gas pipe sizing calculator for low and high pressure systems. (iPhone/iPad app by Carmel Software Corporation.)

- Source: https://appshunter.io/ios/app/hvac-pipe-sizer-gas-plus/id342239204 (this page in markdown: same URL + `.md`)
- Developer: [Carmel Software Corporation](https://appshunter.io/developer/317970398)
- Category: Productivity, Business
- Price: $7.99 with in-app purchases
- Rating: 5.00/5 from 1 App Store ratings · 5 written reviews indexed
- Age rating: 4+
- Requires: iOS 15.6 · 18 MB
- Languages: American English
- Released: 2009-12-05
- Data updated: 2026-09-09
- Monetization: paid
- User reviews in markdown: https://appshunter.io/ios/app/hvac-pipe-sizer-gas-plus/id342239204/reviews.md

## What is HVAC Pipe Sizer?

The "HVAC Pipe Sizer - Gas Plus" application allows you to quickly size a simple low (less than or equal to 1.5 psi) and/or high (greater than 1.5 psi) pressure gas piping system by inputting a number of piping and gas properties. This application combines the functionality of our popular "HVAC Pipe Sizer - Gas Low" and "HVAC Pipe Sizer - Gas High" applications.

This app is now a universal app meaning that it works on both the iPhone and iPad and adjusts its screen size accordingly.

For low pressure gas piping, you can specify the total gas flow in ft3/hr (m3/hr) and one of either pressure drop (in. wg or Pa), pipe internal diameter (inches) or gas velocity (ft/s) parameters. The results include both the exact and nominal pipe diameters and the calculated velocity and total pipe equivalent length. If you are analyzing an existing pipe system, there is an option to input the existing pipe internal diameter and one of either pressure drop or gas velocity parameters to derive the calculated gas flow and other remaining properties.
 
For high pressure gas piping, you can specify the total gas flow in ft3/hr (m3/hr), the upstream pressure (psig or kPa), and one of either downstream pressure (psig or kPa), pipe internal diameter (inches) or gas velocity (ft/s) parameters. The results include both the exact and nominal pipe diameters and the calculated velocity and total pipe equivalent length. If you are analyzing an existing pipe system, there is an option to input the existing pipe internal diameter, the upstream pressure, and one of either downstream pressure or gas velocity parameters to derive the calculated gas flow and other remaining properties.

You can specify additional parameters such as the type of gas, various properties of the gas, the pipe material type, the total length of pipe, quantities for up to 11 different types of pipe fittings, and much more. You can also choose to display values in either english or metric units.

This application includes built-in pipe fitting equivalent length and nominal pipe sizing tables for a wide variety of pipe material types and diameters.

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

This app now includes the HVAC Equipment Locator. Click here for details: http://bit.ly/1yTq539 

The "HVAC Pipe Sizer - Gas Plus" 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

## Key features

- Low and high pressure gas pipe sizing
- Calculate flow, pressure drop, diameter, and velocity
- Universal app for iPhone and iPad
- English and metric unit support
- Built-in pipe fitting equivalent length tables
- Slider controls for quick adjustments

## Pricing and in-app purchases

Base price: $7.99.

**One-time purchases**

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


## Recent user reviews (5 of 5)

All indexed reviews: https://appshunter.io/ios/app/hvac-pipe-sizer-gas-plus/id342239204/reviews.md

### 1/5 — Crap

*2012-06-19*

Load of crap all in wg no millibar settings and useless. Not worth the money.

### 5/5 — Good simple tool for gas pipe sizing

*2010-05-16*

I mainly do high pressure gas pipe sizing for my job at a processing plant. This handy little tool helps me spot check the velocities, diameters, etc. for some of those pesky pipes that are giving me troubles.

This app is quite versatile since it allows me to first specify gas flow and then upstream/downstream pressures to get predicted diameters and velocities. It also allows me to specify diameters and pressure loss to get gas flows.

Great app!

### 5/5 — Great value and useful for HVAC techs

*2010-05-03*

Simple interface. Good tools for sizing low and high pressure
gas piping. I have used this app in the field to guestimate the size
of natural gas piping into homes. Quite accurate. I've already gotten
3 or 4 updates since I bought the app and they were all very useful
updates, not just bug fixes. I see Carmel as a long-term company, not
just a fly-by-night. Good work!

### 5/5 — Good stuff

*2010-05-03*

High pressure calcs: Good stuff and accurate after comparing to the Waymouth equations that I have programmed into my Excel spreadsheet. 

Low pressure calcs: These calcs appear accurate. I use this the most to look at natural gas piping into homes, etc.

### 5/5 — Useful app

*2010-05-03*

This is very useful for my business involved with process piping. I often go into the field and need to do some quick calcs of gas flow rates based upon the pipe diameter. The calcs are quite accurate after comparing to my desktop-based calcs. I use the high-pressure calcs more than the low-pressure, but they both seem accurate.

Great work.

## Frequently asked questions about HVAC Pipe Sizer

### What types of gas pressure does HVAC Pipe Sizer support?

HVAC Pipe Sizer - Gas Plus supports both low pressure (less than or equal to 1.5 psi) and high pressure (greater than 1.5 psi) gas piping systems.

### What information can I input to size a gas pipe?

For low pressure, you can input total gas flow and either pressure drop, pipe internal diameter, or gas velocity. For high pressure, you input total gas flow, upstream pressure, and either downstream pressure, pipe internal diameter, or gas velocity.

### What results does HVAC Pipe Sizer provide?

The app provides exact and nominal pipe diameters, calculated velocity, and total pipe equivalent length. It can also derive gas flow if you input existing pipe dimensions.

### Can I use HVAC Pipe Sizer on my iPad?

Yes, HVAC Pipe Sizer - Gas Plus is a universal app that works on both iPhone and iPad, adjusting its screen size accordingly.

### Does HVAC Pipe Sizer have ads?

No, HVAC Pipe Sizer - Gas Plus does not contain advertisements. It is a paid application.

### How often is HVAC Pipe Sizer updated?

The latest version, 5.2, was last updated on December 12, 2025, indicating regular updates to maintain functionality and compatibility.

### What is the price of HVAC Pipe Sizer?

HVAC Pipe Sizer - Gas Plus is available for a one-time purchase of $7.99.

### What other HVAC apps does Carmel Software Corporation offer?

Carmel Software Corporation also offers HVAC Residential Load Calcs, HVAC Quick Load Plus, HVAC Quick Load, and HVAC Toolkit for iPhone and iPad.

## Version history (last 5 releases)

### 5.2 — 2025-12-12

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.
3. Optimized for iOS 26.

### 4.8 — 2023-03-21

1. Optimized for iOS 16 and iPhone 14
2. Updated help

### 4.5 — 2021-11-10

1. Minor UI update
2. Updated email subject text
3. Updated launch icon

### 4.3 — 2021-11-04

1. Optimized for iOS 15 and iPhone 13
2. Updated the UI for the Gas High module
3. Updated the UI for the Gas Low module
4. Updated help

### 4.2 — 2020-08-06

1. Updated the app launch screen per new Apple iOS guidelines.
2. Updated Google Analytics and Crashlytics

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## More apps by Carmel Software Corporation

- [HVAC Duct Sizer](https://appshunter.io/ios/app/hvac-duct-sizer/id317970395)
- [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

[pipe sizing calc hvac](https://appshunter.io/ios/topics/pipe-sizing-calc-hvac)

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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 2026-09-09.*