Modelling the performance of different ventilation systems on VOC removal in a full-scale room.

Among significant occupational health problems are building-related health complaints and symptoms. A potential cause has been identified as the elevated concentrations of various types of indoor contaminants, which are frequently associated with inadequate ventilation. This research aimed to model and evaluate the performance of several ventilation methods on volatile organic compound (VOC) removal in indoor environments. The time history of the contaminant concentrations in a model office have been simulated using a newly developed computer model. Studies of three ventilation methods, namely displacement ventilation and two mixing systems are described. VOC sources are assumed to be from the floor level, one with a constant flux and the other a fast decaying source (wood stain). Simulation results show that different ventilation methods affect the contaminant distributions within the room. When the contaminant sources are distributed on the floor and not associated with a heat source or initial momentum, displacement ventilation may behave like a perfect mixing ventilation at or above the breathing zone. Conventional "mixing" diffusers, on the other hand, could perform better or worse than a true mixing system. The computer model could be used for selecting appropriate ventilation systems and analyzing indoor air quality.