System Syzer is an HVAC tool that helps with piping system design. The application is based on the original plastic wheel calculator by designed by Gil Carlson of Bell & Gossett. It was first introduced in 1963 and has since been distributed to well over a hundred thousand engineers and tradesmen.

The tool is made up several different calculators. There is a calculator for friction loss and velocity through pipe based on your fluid conditions. Use it to determine the relationship between fluid temperature, system flow and heat/cooling load. There is a Cv tool that can help in multiple ways.

We have also bundled the Circuit Setter® / Triple Duty Valve calculator that is very handy for balance contractors. Use it during design to help predetermine valve settings and out in the field to determine flow through the valves based on pressure drop readings.

What’s New

Version 2.0.2

• Fix Circuit Setter bug where the "Settings" value would not reset to 0 when tapping the reset button.

Ratings and Reviews

MichaelW_bg ,

Ebiz guy

Confirmed problem with 50% setting on Circuit Setters is fixed in the latest version.

Flow state causes confusion but is correct. There are three states for flow: laminar, transition turbulent and complete turbulent. Transition turbulent was shortened to just "transition" in the app. However, most engineers understand this state as simply "turbulent". Further confusion is caused since "transition" sounds like it is in the Reynolds range where you cannot reliably predict the flow state. The flow labels have been improved in the full windows version. The next app upgrade will clarify the flow state labels.

Robert (B&G) ,

Well designed

Good app. Must have. Easy to navigate and much easier than carrying around the wheels. Would like to see the Circuit Setters and TDVs broken up so it is easier to quickly get to the proper device. Would like to see recommended maximum flow rates for pipe size.

SureShot$ ,

Works great

I find it really useful when calculating pressure drop on fluid other than 60F water.


Xylem Inc.
6 MB
Requires iOS 8.0 or later. Compatible with iPhone, iPad, and iPod touch.
Age Rating
Rated 4+
© Bell & Gossett a unit of Xylem Inc.


  • Family Sharing

    With Family Sharing set up, up to six family members can use this app.

More By This Developer

You May Also Like