Getting Started with TRNFlow

TRNFlow is a airflow network model option for TRNSYS multizone component, Type56. Here are some tips on how to get started with TRNFlow.

Creating a new TRNFlow project

The basic operations are the same as for a usual multizone model, but the TRNFlow component will be used.

Putting TRNFlow components into the project.

After installing the TRNFlow option, TRNFlow (Type56-TRNFlow) will appear in the list of components.

To create a new TRNFlow project, place the component in your project.

Turn on the TRNFlow state

After creating a building model in TRNSYS3D/SketchUp and importing it to TRNBuild, enable the TRNFlow feature.

Click “TRNFlow” in the Navigator window to display the TRNFlow window, and click “on” for the State to enable TRNFlow.

You will now be able to create an airflow model in TRNBuild.

Then save the file, close TRNBuild, and don’t forget to “Update building variable list” in Simulation Studio.

Enabling TRNFlow feature

TRNFlow is turned off by default. Before starting the calculation, you need to enable the following two settings.

Type56-TRNFlow, Input, TRNFlow value

On the Input tab, there is a value to turn the TRNFlow feature on and off. Set this value to 1 to enable the TRNFlow feature.

As a side note, you can use this value to switch the time of day or period when the TRNFlow feature is used. For example, you can use TRNFlow to study natural ventilation only during certain periods of time, such as summer or mid-season.

Connecting wind direction and speed

TRNFlow requires wind direction and speed data for its calculations. Please connect the wind direction and speed from the weather data reader to the Type56-TRNFlow.

Absolute ambient barometric pressure setting

Input also provides absolute ambient barometric pressure. Please refer to the linked article to set absolute ambient barometric pressure.

For wind direction and wind velocity, please also set conditions for meteo stations and building location.

The TRNFlow setup is now almost complete. Then use TRNBuild to configure the airflow network.

Applying TRNFlow to an existing project

To add an airflow network to an existing multizone project, replace the Type56 component with Type56-TRNFlow.
Select the Type56 icon, click the right mouse button and select “Replace” from the menu.

Now, select “C:\TRNSYS18\Studio\Proformas\Loads and Structures\Multi-Zone Building with Air Flow (TRNFLow)\Type56-TRNFlow.tmf ” and replace the component.

Make sure the icon of the component has changed to Type56-TRNFlow.

Then, enable the TRNFlow feature and connect the wind direction and speed in the same way as when creating a new project.

Test Environment

It has been confirmed that the software works in the following environments.

  • Windows10 Pro(64bit, 21H1)
  • TRNSYS18.02.0002(64bit)


  • Hi Yuichi

    I am a student doing BIPV simulation by using Trnsys. But I don’t have trnflow to simulate natural ventilation behind the PV panels.

    However, my university does not have such license as well. The price is too expensive for me to afford and my university does not have funding to support for me. Can I borrow or rent Trnflow license for one month from you ?

    Many thanks
    Best regards

    • Roger,

      TRNFlow is a commercial product. According to the license agreement, you cannot rent or borrow licenses.


Leave a Comment

Your email address will not be published. Required fields are marked *