Evaluation of draught in surgical operating theatres: proposed revision to (NEN)-EN-ISO-7730

Purpose – The purpose of this paper is to show that it is advisable to evaluate draught in an operating theatre in a different manner than the method according to NEN-EN-ISO-7730. The NEN-EN-ISO-7730 is an international standard for the analytical determination and interpretation of the thermal comfort of the human body and the local thermal comfort like for instance draught. Design/methodology/approach – Using a CFD computer program, it is possible to evaluate draught in an operating theatre in the design stage, according to different mathematical draught models. Findings – It would seem advisable to begin with the draught model developed by Griefahn. The model does, however, need to be modified to include the effects of temperature sensation and the direction of the air stream, so that it becomes applicable to a thermally cool environment (PMV<0) and a vertical air stream, the air pattern prescribed for an operating theatre. Originality/value – It can be demonstrated that by implementing the proposal in this paper in a CFD program, the possibility exists to be able to evaluate, in a responsible fashion, the results for a much broader range of parameters than is currently possible by means of the NEN-EN-ISO-7730.