By Georg Hewelt, Product Manager Trimble Nova, Trimble International
Thermal calculations relating to thermal regulations, summer heat loss and summer heat gain form a fundamental basis for the design of the building's technical installations. The choice of heating, air-conditioning and ventilation equipment will depend directly on the results.
Thermal calculations involve parameters, some of which are taken directly from the architectural model, unlike fluid network dimensioning calculations, where the input parameters are entirely specifiable by the engineer. Many users wish to optimize thermal model input by retrieving data from the architect's model, quickly and efficiently.
The emergence of BIM in construction projects makes it possible to determine a thermal surface model from an architectural model. The IFC exchange format offers a standardized exchange of information relating to a model from architectural software to thermal software.
Current status of the architectural model
To know whether an architectural model can be interpreted in a thermal model, it's necessary to understand what the architect wants the model to show.
When architects create their models in an application, criteria such as 3D visualization, 2D printing plans, quantity take-offs and quantity take-offs come to the fore. In practice, this means modeling elements that are not always relevant to the thermal surface model (e.g. furniture, technical cabinets, flooring, etc.).
In addition, the parameters that are important for thermal calculations are not always adequately provided: for example, considering the glazing and blind casing of a window separately can prove problematic when calculating summer heat gain.
