Data Exchange for Thermal Modelling and Ventilation Simulation

Data exchange is the process by which information is transferred between the engineer and software and between one piece of software and another. Building and plant simulation involves handling large data sets describing constructional details, system components and reference data. The time required to prepare and check the data is significant and is one obstruction to the widespread use of simulation within the design process. Links between drafting systems and analytical tools offer an obvious way to speed up the process and reduce input errors. The concept of data exchange, however, involves much more than the automated transfer of information from drawings: it allows one analytical program to talk to another without intervention from the operator. Thus, for example, the engineer could combine a favoured method of heat loss calculation with an assessment of infiltration provided by a different software vendor. The same applies at output: the results could be ported to a favourite graphical display package rather than that supplied by the vendor. There is also the possibility to prepare data bases that could be used to help maintain the systems throughout the life of the building. However, while simple in concept, to be effective, data exchange requires the community wide acceptance of a standard way to describe data. This paper looks at a single aspect of data exchange i.e. the linking of analytical tools. The intention is to indicate the minimum requirements necessary to obtain valid simulations. Two examples are considered, i.e.: The linking of a zonal air flow model with a dynamic thermal model; An analysis of the effect of thermal boundary conditions on predictions made using computational fluid dynamics software. The work described within the paper formed part of a Subtask 4 of IEA Annex 30 Bringing Simulation to Application.