COMPUTATIONAL FLUID DYNAMICS or CFD modelling is frequently required by AHJs as part of the analysis of the smoke management systems for car parks and building atriums. Output of CFD analysis – plots of temperature, visibility and smoke clearance height – allow designers to evaluate multiple fire scenarios and iterate between system design parameters before arriving at an optimum solution that complies with the Code requirement (i.e. “tenability criteria”) and saves cost by helping avoid over-engineered systems. While CFD simulation is carried out at the design stage, the effectiveness of the system in actual operation can be demonstrated using Hot Smoke Testing once the equipment is commissioned.