Numerical modelling was required to assess a large number of fume cupboard exhausts during roof refurbishment activities. Thus, different wind conditions and exhaust gases were assessed through a series of CFD simulations. The MEP team were able to improve the design by increasing the stack heights and exhaust gases dilution, reducing any adverse effects at the pedestrian areas.
For the current assessment, a release of Chloroform has been considered, representing a worst-case scenario of the substances being utilised in the Chemistry Building laboratories. The EH40/2005 workplace long-term exposure limit of Chloroform and the corresponding short-term exposure limit (three times the long-term exposure limit) were defined as critical concentration limits.