Our software in version 18 performs better than ever. Functions were improved and some important ones added. Find out about new features, the basics of TRNSYS and download the demo version which allows you to simulate different examples.


New Features

The current release has many new interesting features

How to simulate with TRNSYS?

An important feature of TRNSYS is its open, modular structure, which allows the user to combine individual components to form any system. For project creation, the user has access to the graphical simulation environment TRNSYS Studio, in which the components are selected, parameterized and linked and from which the simulation is started. Each output quantity can be output for each time step or as an average value over freely selectable time intervals. Energy quantities are calculated as an integral of the power output over a time period to be specified.


Which components are available?

The standard library contains a wide range of components. Users can also integrate their own components and link TRNSYS to other simulation programs. Numerous components are also available as Add-Ons e.g. to model geothermal energy systems or air flow in buildings.

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Physical Components

In addition to buildings, the physical components allow the simulation of conventional, renewable and hybrid energy systems. They are divided into the following groups:

  • Thermal solar collectors
  • Heat accumulator
  • Hydraulic elements
  • Heating and cooling devices
  • Building components
  • Controllers
  • Electrical components
  • Hydrogen systems

Multi-zone Building Model

TRNSYS has a powerful multi-zone building model, which is characterized by the following features:

  • coupled thermal zones with multiple air nodes
  • arbitrary number of building elements (user-defined constructions, libraries)
  • detailed window model and thermoactive components
  • variable internal convective and radiative heat loads
  • short and long wave radiation models that include external and internal shading
  • natural and mechanical ventilation, interzone air exchange
  • humidity and daylight calculation
  • internal/ external control strategies for sun protection, ventilation, heating and cooling
  • evaluation of local comfort

Auxiliary Components

For meteorological data, special weather data readers are available to read the common standard formats such as TRY, TMY3, Meteonorm etc. and other free formats. Components for input and output, operation and occupancy schedules,  data averaging and interpolation are available, as are components for the calculation of physical processes (e.g. material properties, radiation conversion, etc.) . Users are also able to write their own equations.Komponenten für gekoppelte Simulation

Components for Coupled Simulation

TRNSYS can be connected to other simulation environments by means of coupling modules included in the software package making it possible to exchange results between the programs at each simulation step. BCVTB (Building Controls Virtual Test Bed), for example, is a software environment that allows experts to couple different simulation programs for co-simulation or simulation programs with actual hardware. Coupling to other programs can be realized by creating a corresponding component.

Own Components

If more complex systems of equations need to be solved, it is possible to program your own components and integrate them into the simulation. According to the modular philosophy the mathematical model of each component is described by its own subroutine. Custom components can be created in common programming languages (FORTRAN,C, C++, etc.) and integrated as a DLL (dynamic link library) in TRNSYS. Since the source code of almost all components is available, standard components can also be modified by the user.

Prices & Order

Transsolar is developer and official distributor of TRNSYS with sales rights in all countries except France and the USA. Transsolar has exclusive sales rights in Germany, Austria and Switzerland. In our opinion, the quality of a software product is not only characterized by the product itself, but also by the available support. In addition to a basic support for license questions and program errors, Transsolar offers its customers an extended support for solving TRNSYS problems.


  • Testversion
  • Limited functionality




  • Commercial use
  • Full functionality

4800 €


  • For Institutes
  • Full functionality

2400 €