How do electric air cleaners work?
Media air filters – at the microscopic level – consist of an interlocking network of fibers that appear quite porous. This porosity is necessary to allow air to pass through the unit with minimal pressure drop. Despite appearances, the fibrous media captures a surprising number of particles, using 3 different methods: diffusion, impaction, and interception. Diffusion: the random trajectory of many particles, jostled by air molecules, carries them directly into the path of a fiber. Impaction: Many particles are too heavy to move out of the path of a fiber; they slam into a fiber and stick. Interception: Random air currents cause particles to sweep too close to a fiber; molecular attraction grabs the particle.
