The HVAC Pipe Sizer - Gas Low application allows you to quickly size a simple low pressure (< 1.5psi) gas piping system by inputting a number of piping and gas properties.


You can specify the total gas flow in ft^3/hr (m^3/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.


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 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 is available to display both english and metric units.

The HVAC Pipe Sizer - Gas Low application was designed by Carmel Software Corporation, a leader in HVAC design software since 1995. In fact, our software currently powers the analysis capabilities of Autodesk's (makers of AutoCAD) 3D modeling software tools. Also, ASHRAE has hired Carmel to custom develop the mobile apps for their various standards.

Click here to go to Apple iTunes to download the HVAC Pipe Sizer - Gas Low app.