ABSTRACT
The collection efficiency of glass wool air filter decreases with the air velocity, which is followed by an increasing trend. A similar type of observation is also reported in the literature. The decrease in collection efficiency at low air velocity is mainly due to the diffusion phenomenon for the collection of particles. However, at higher velocity, the collection of particles is mainly due to interception and inertial impaction. The number of airborne microbes in the inlet and outlet is determined at different air flow rates using a plating technique containing nutrient agar. The particles when entrained in the streamlines of air are collected by contact with the fibers. The flow pattern of the particles deviates from that of the air flow due to the inertia of the particles as they approach the cylindrical surface.
