Intelligent CAD as an interface to thermal simulation programs

Thermal simulation programs for buildings have been available for many years. They vary from simple methods that can be performed at the sketch design stage using a spreadsheet through to sophisticated dynamic thermal simulations requiring mainframe computers. However, these methods are not widely used by building designers during the early stages of design when the most important decisions are made. Explanations for this are that the preparation of the data can be time consuming and few building designers are confident in interpreting the results of the simulations. One method to encourage designers to use thermal simulation tools 4 to incorporate these tools in the drawing environment that they use. Simulation programs will then be seen as part of the design process rather than an appendix. This paper describes a research project, TES (Thermal Expert System), that integrates the graphical methods with which building designers are comfortable and thermal simulation tools. Work is currently restricted to detached houses. The user interface is based on an intelligent CAD system which only requires the designer to enter the features of the building which differentiate it from an archetype. The major task in developing this system was the implementation of the intelligent database (knowledge base) representing the building. This knowledge base had to store information informs that were suitable for interactive manipulation by the user and provides the information required for the thermal simulations. The integration of an intelligent CAD interface with thermal simulation programs allows thermal analyses to be more easily carried out while designing a building and provides either detailed or non-technical information as requested by the user.