When it comes to sheer air purifying power, the Alen is top rated with our testers. You'll pay out a quality for that efficiency, and it is a beast of a unit, but the Alen will be the uncommon equipment which can seize contaminants down to 0. The Coway 200M Accurate HEPA is a superb air purifier for homeowners of weighty-shedding or smelly pets.