Photoionization, or PI, begins its magic as soon as foul air enters the unit, first clearing out large particles through dust filters. It then progresses to the heart of the process in the UV chamber, where the real transformation occurs. Odourous pollutants are neutralized by a powerful duo of free radicals and activated oxygen. This clean air, still carrying some remaining pollutants, is polished in the catalyst compartment for a final touch-up before being released back, fresh and odour-free.