An Air Purifier or Air Cleaner is a portable, electric appliance that removes fine particles, such as dust and pollen, from indoor air. They clean air with either fibrous media air filers or electronic air cleaners. The effectiveness of an air purifier is measured using a measurement created by AHAM, with the intent of standardizing air purifier effectiveness ratings. That measurement is the Clean Air Delivery Rate (CADR) and refers to the cubic feet per minute of air that has had all particles of a given size distribution removed. The CADR of a unit is measured for dust, pollen and tobacco smoke particles.
Energy savings come from lower operation power per CADR, resulting in reduced energy consumption. The RTF measure is the Installation of a new, ENERGY STAR certified portable room air purifier. The RTF specification is split into 4 measure identifiers, 30 ≤ Smoke CADR < 100, 100 ≤ Smoke CADR < 150, 150 ≤ Smoke CADR < 225, Smoke CADR ≥ 225, with a minimum CADR/W rating requirement for each.