Application of Simulation programs to the Assessment of Overhekating Rosks in Buildings and the of IEA Annex 21

This paper describes the objectives of International Energy Agency (IEA) Annex 21 and the ongoing work of Subtask B which deals with how programs should be used for particular applications. Well documented procedures for using programs need to be developed to fulfill a real need by increasing consistency of performance assessment, aiding in training, allowing improvement of procedures and promoting quality assurance. The emphasis in this work is on how programs are applied, so that the programs are taken as 'given'. The assumptions embodied in programs are relevant to the choice of program for a particular purpose and application, but the immediate focus here is on how best to use them rather than on how their design might be improved. The way programs should be used to address a particular purpose has been termed a Performance Assessment Method (PAM) and an attempt has been made to structure these using a documentation proforma, or 'Shell'. A prototype expert system has also recently been developed as an aid to systematic documentation and information retrieval. It is expected that many different PAMs will be in use by practitioners and researchers, but that there will be common elements which will become clear once a number of PAMs have been documented. Documentation is essential so that, firstly, the assumptions in currently adopted methods can be made explicit and thus open to analysis, secondly, that quality assurance can be carried out, and thirdly, that portions of the assessment method for one application can be re-used for different applications. Thus part of the data selection/analysis procedure can be applied equally well to an overheating investigation as to an energy retrofit. The development of a library of accredited PAMs could lead to an important increase in the quality and credibility of the use of prediction programs in the building field.