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CFD should come first – fire engineering in the design process

As smoke control specialists we use CFD (computational fluid dynamics) to work out how smoke will react in building areas of different types, using criteria such as expected fire energy output, corridor dimensions, distance between doors, stairwell locations, damper size etc etc. It’s a very important part of designing, for example, a mechanical smoke shaft setup (such as our VeriShaft system) and therefore is a very important part of making sure a new high rise residential building is a safe place to live.
But there’s a problem, one that resides with how the construction design process works altogether.
All too often CFD models are only applied to a new build toward the end of a project, by which time the building is half-built and the locations of the shafts etc are fixed; in other words, when it’s too late to make meaningful improvements to the layout of the smoke control system. Any unexpected or undesirable results lead to scrabbling around, looking for fixes and compromises to correct the issue and ensure the building is as safe as it needs to be. It’s not the sensible approach, it’s not the cost-effective approach and it’s not necessarily the most effective approach.
The ideal
It’s not always done this way. On some projects the fire engineers are enabled to do the modelling right at the start and these projects are almost always better designed as a result.
The downside, from a certain point of view, is that the client – rather than the contractor – has to foot the bill for the work and take some responsibility for it. It also means the fire engineer must be retained throughout the entirety of the project in order to provide the necessary design warranties (if not, the installation contractor is often asked to warrant the system). This then means the CFD model must be done again, adding more unnecessary cost.
It’s a tricky problem to solve, for sure, but if we are all as serious about making the safety of building occupants our absolute priority – which we surely must – then the fire engineering process (including CFD) must be completed before the building starts to go up in order allow it to be changed and made as successful as it possibly can be.