About BSim

​BSim (Building Simulation) is an integrated PC tool for analysing buildings and installations.

The BSim program package consist of seven program modules:

SimView - Graphic user interface

SimView is the graphic user interface of several applications included in the program package and the graphic model editor. SimView is used for creating and defining features and properties of the building such as geometry, constructions, materials and installations.

The model is shown simultaneously as a 3D drawing, a floor plan and two sections. Moreover, a hierarchical tree structure is shown on the left of the display, allowing the user to access and edit individual parts of the building model. Data can be transfered to other programs for further processing, fx DirectX.


Tsbi5 - Indoor climate, thermal and moisture conditions

tsbi5 is the thermal simulation core of the BSim program package. tsbi5 makes it possible to perform a dynamic simulation of the indoor climate, energy and moisture conditions in buildings. This can contribute to the selection of heating, cooling and ventilating systems at the design stage of new buildings and refurbishment of existing buildings and installations.

By using tsbi5, it is possible to test different strategies for obtaining desired indoor conditions in buildings such as utilising solar shading, venting, ventilation, cooling etc.

A unique feature of the program is an extension model for synchronous simulation of the moisture and thermal conditions in the spaces and the constructions of the model. It is, for instance, possible to make precise predictions of moisture variations in the indoor climate and the risk of condensation in the building constructions. Data can be transfered to other programs for further processing, fx CFD (Computional Fluid Dynamics).


Xsun - Sunlight and shadows

XSun is a tool for making detailed analyses and simulation of direct solar radiation through windows and openings in building constructions. Analyses of shadows from remote objects such as neighbouring buildings can also be analysed by using XSun. During thermal simulations with tsbi5, the routines of XSun are used to distribute direct solar energy to the exact location in the model.

Simulations with XSun can be shown as animations of the movements of sunspots in the spaces of the building model. Animations can be saved as standard Windows video sequences and be shown on a PC, even where BSim has not been installed. Data can be transfered to other programs for further processing, fx Radiance.


SimLight - Daylight calculations

SimLight is a model for calculating daylight conditions in a reference point, or in a grid of points in a plane, in a space with simple (convex) geometry.

Results from the calculations with SimLight can be used directly for controlling the use of artificial light in tsbi5 simulations. Data can be transfered to other programs for further processing, fx Radiance.


Be06 - Danish Building regulations compliance checker

The Danish compliance checker – Be06 is EN ISO 13790 and other relevant standards on calculation of installations - is not part of the BSim package. By means of this tool it is possible to check if the heating requirement of the entire model is within the limits of the Danish building code.

Be06 is a stand-alone program that can be used in combination with the BSim program package. Thus a building model made in BSim can be used directly in Be06, resulting in a calculation of the monthly heating demand over the heating season. Be06 has a built-in Danish climate file, but other climate files can be made and used for calculations.

SimDXF - Importing CAD drawings

SimDXF can be used to create a spatial geometry from a CAD plan drawing saved in DXF format. This enables CAD drawings to be used as a basis for establishing complex model geometry in BSim. System lines are selected from the CAD drawing and they generate the 3D geometry when opened in SimView.


SimDB - Database with constructions and materials

A standard database (MS-Access) containing data for a large number of different materials, constructions, windows and surfaces is also included in the BSim package. The contents of the database can be extended as needed.

SimDB is the BSim user interface to the database and even in models with several hundred constructions and windows, it is possible with only a few clicks on the mouse to attribute data to different groups of constructions, e.g. all external walls by one click on the mouse button.



For further information please contact Kim B. Wittchen, Karl E. Grau or Kjeld Johnsen.