The application is used for calculating air velocities in fabric ducting and diffusers. Upon entering a given airflow, the velocity for the given size is displayed. Upon changing the size, we get the velocity for the given airflow. Values can be entered by moving the ruler or by typing particular values.

The color of the speed scale signalizes suitability of the calculated velocity. Red means an unacceptable, orange risky and green suitable velocity. Blue signalizes excessively dimensioned.

You can modify the cross section by clicking on the cross section picture. By clicking on the units, their offer is analogously displayed.

The calculations are exact and rounded to the values used in real life. Nevertheless, the speed evaluation is only informative.

For more information, please visit

What’s New

Version 1.2

In order to correctly design the air distribution, it is necessary to know the reach of flows from perforation. These values are determined by entering the static pressure in the duct along with its length and selecting the cross section angle that will be filled by the perforation. The axial flowing speed in the selected distance from the duct is shown on the scale. Alternatively, you can find the distance at which the speed has a certain value. The next screen will show you an illustration of the distribution of speed zones of the whole air flow.


TreeTech s.r.o.
13.5 MB

Requires iOS 8.0 or later. Compatible with iPhone, iPad, and iPod touch.



Age Rating
Rated 4+
© Kryštof Mrózek


  • Family Sharing

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

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