00904nas a2200109   4500008004100000245005500041210005400096260003600150520053200186100001800718856005800736       1997                        eng d00aFault Modelling in Component-based HVAC Simulation0 aFault Modelling in Componentbased HVAC Simulation  aPrague, Czech Republicc09/19973 aModels of faulty components or processes may either be used on-line as part of a fault detec- tion and diagnosis (FDD) system or may be used in simulations to train or test FDD procedures. Some faults may be modelled by choosing suit- able values of the parameters of fault free models, whereas other faults require specific extensions to fault free models. An example of the modelling of various faults in a cooling coil subsystem is pre- sented and different methods of using simulation in testing and training are discussed.1 aHaves, Philip  uhttp://www.ibpsa.org/proceedings/BS1997/BS97_P101.pdf