Object Oriented Modelling of Variable Envelope Properties in Buildings

The paper deals with some important aspects of continuous systems modelling approaches. Namely the traditional approach is based on block oriented schemes in which causal relations play an important role. However this causality is artificially generated in order to fulfil appropriate conditions for simulation on conventional sequential computers. Fortunately new concepts which are based on object oriented approaches, physically oriented connections and algebraic manipulations enable the so called acausal modelling. Both approaches are used in the modelling of thermal flows in intelligent building. Advantages and disadvantages of two concepts and environments are discussed. As validation is always the most important phase of each modelling project a small physical “chamber” was built. The second part of the paper demonstrates the efficiency of the developed simulation model. With the simulation we studied how to compensate or efficiently use variable outdoor conditions, e.g. solar radiation and outdoor temperature in order to assure the appropriate indoor conditions. This was not performed with conventional approaches, e.g. with heating, cooling, ventilating, humidifying, etc. but with on line dynamical adaptations in the building envelope. Variable wall insulation, movable window insulation, movable shading system and rotating object were proposed and studied. Key-Words: Object oriented modelling, Simulation, Acausal modelling, Thermal flows, Intelligent building