Detailed simulation of transient thermal effects in building enclosures

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BISTRA Features


  • Transient thermal simulation of all shapes in 2D
  • Geometrical input via BISCO format (steady-state variant)
  • Temperature dependent material properties
  • Detailed solar processor
  • Graphic animations (AVI files) of time varying temperatures
  • Software operational in English, French, German and Dutch


BISTRA Application fields

Application fields

  • Transient analysis of thermal bridges / construction elements
  • Glass fracture caused by solar radiation
  • Fire engineering (according to Eurocodes)
  • Floor heating (EN ISO 11855-2)
  • Ground heat losses (EN ISO 13370) and frost insulation (EN ISO 13793)
  • Phase change materials (PCM)
  • Dynamic thermal analysis of heating / cooling
  • Calculation of solar heat gains


BISTRA Input and geometric modelling

Input and geometric modelling

  • Same as in BISCO (also drawing and fill tools for bitmap editing)
  • Additional input of material densities and specific heat values
  • Thermal conductivities and specific heat values may be temperature dependent (e.g. useful in fire simulations)


BISTRA Dynamic boundary conditions

Dynamic boundary conditions

  • Boundary conditions are time dependent functions: constant, steps, periodic, reference climate, fire curve, user defined
  • Preview (with zoom) of time functions and temperature functions (material properties)
  • Improved simulation of (non-linear) radiation and convection by use of RADCON module



RADCON feature for BISTRA

  • Detailed simulation of radiation based on view factors

  • Extremely fast and stable calculation of non-linear radiation problems

  • Convection based on (calculated) convective heat transfer coefficient

  • Transparent materials for small cavities: conduction + radiation

  • Validated according to EN ISO 10077-2:2017 (radiosity method)




  • Graphic animations (AVI files) of time varying temperatures
  • Snapshots at any time step
  • Tables and graphs of time varying temperatures and heat flows



BISTRA Compatibility with other Physibel tools

Compatibility with other Physibel tools

  • BISTRA can read BISCO data
  • VOLTRA can read BISTRA data
  • Same function definitions as in CAPSOL


BISTRA Licence options

Licence options

  • BISTRA is available with subscription licences (stand-alone or floating)
  • A subscription licence gives you access to the latest version of BISTRA, technical support and Physibel Knowledge Base.
  • More information on the difference licence options can be found here

what's new in version 5?

Version history


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