Models that offer the best CADR smoke level can yield a reading of up to 450. The greater the better, but if you need a purifier for a small room, CADR 80 is more than enough. For example, hOmeLabs 3 in 1 Ionic Air Purifier can cover up to 50 square feet, that’s why its CADR 85.2 copes perfectly well with getting rid of smoke in a short time.