Abstract

A ventilation device uses a cross-flow fan and one or more filters, where the filter preferably has a J-shape that at least partially surrounds the rotor of the cross-flow fan. In one embodiment, the filter includes a plurality of pleats, preferably along a bottom surface of the filter. The filters preferably remove particles, undesired gases, and micro-organisms. A filtration and ventilation system with at least one first ventilation device and at least one second ventilation device larger than the first ventilation device, as well as a method of filtering contaminants out of air using a personal ventilation device, are also disclosed.