Computer based design aids have much potential to improve the productivity of the design process and provide more confidence in the performance of a building. Although sophisticated design aids have existed for some time there is still a reluctance to use them to full advantage. This is particularly true of the strategic phase of building design. The barriers to the use of computer models are explored and the means by which they can be overcome via the education of post-graduate students and practising professionals are discussed.

Since two years, the Dutch building consultancy practice has been supported by an integrated design environment to base its advices on. This environment, called the Uniform Environment or UO in Dutch abbreviated form, has been developed by the Association for Computerisation in the Building and Installation Technology (VABI) and TNO Building and Construction Research. The basic principle of the UO is that all data, associated with a building project, is stored in one database, irrespective of the design tools being used in the project.

A new integrated simulation system for the building services design and facilities management purposes is being developed by Insinööritoimisto Olof Granlund Oy. The system covers the thermal simulation needs of the whole building life cycle from the preliminary design to renovations. The main components of the simulation system are a simulation database, user interfaces, a result module, a building geometry modeller and a calculation engine. The building geometry modeller generates a 3-D surface model of the building. The calculation engine of the first version is DOE 2.1E.

In  this  paper,  the  parameters  in  a  building  thermal simulation model are tracked, which are subject to modeling uncertainty, i.e. uncertainty arising from commonly applied physical assumptions and simplifications. As an example, the simulation of the thermal comfort performance of a naturally ventilated office building without cooling plant is analyzed.

The IMAGE (IMplementation of Advanced Glazing in Europe) project was funded by the European Commission and involved glass manufactures, onsultants and research organisations (see acknowledgements).

If a map of a city is encoded as a Digital Elevation Model, it becomes amenable to image-processing software, such as the public-domain NIH Image application. Standard techniques can be used to measure plan areas and volumes and simple macros can be devised to measure perimeter length and wall areas. A macro for calculating shadow volumes is elaborated for the simulation of solar gains and daylight, including indirect lighting, leading to the possibility of an image-based urban-scale environmental model.

Combined conduction-convection-radiation heat transfer in concrete block walls with one or two cavities is simulated using the CFD code “FIDAP”. It is shown that the resistance of the block itself depends on the temperature difference between the external and internal parts. The heat flux is shown to vary appreciably, approximately 30 %, between the upper and the lower parts of the block.

A new method aimed at the selection of the best reduction technique for each given invariant linear system, such as those obtained when modelling the thermal behaviour of building envelopes, is presented here. The method can be divided into three main steps. In the first step, we evaluate a priori whether or not the selection of the reduction technique is critical knowing either the desired reduction order or either the level of accuracy required for the reduced model.

Training new users of simulation programs typically focuses on a single tool–specific techniques for interacting with, creating models, and assessing performance. Unfortunately, this tends to produce users limited by a particular tool’s capabilities—not users that can easily decide how best to tackle a simulation problem, regardless of tool.

Models of faulty components or processes may either be used on-line as part of a fault detection and diagnosis (FDD) system or may be used in simulations to train or test FDD procedures. Some faults may be modelled by choosing suitable values of the parameters of fault free models, whereas other faults require specific extensions to fault freemodels. An example of themodelling of various faults in a cooling coil subsystem is presented and different methods of using simulation in testing and training are discussed.