Air quality in the near zone of humans with different ventilation strategies

The concentration in the convection flows ofresuspended particles from the floor area wasexperimentally investigated under laboratoryconditions with different ventilation strategies.It was concluded that the number of smallparticles transported into the breathing zone waslarge with a forced resuspension; however thereseemed to be little risk of resuspension ofparticles from the floor due to the air supplyunder normal conditions. The geometry of thesimulators and the layout of the room had a biginfluence on the exposure. The particleconcentration in the convection flows was muchhigher with displacement than with mixingventilation indicating a higher exposure risk. Inprevious studies of particle exposure theconcentrations are mostly presented in particlemass but here the results are presented innumber concentration. As potential healthproblems are more closely associated withparticle number or surface area than withparticle mass this study can be of interest whendesigning a ventilation system.