How do I make a fair comparison of air purification systems?
When the particle size and filter efficiency of any two air cleaners are the same (as they often are), the Clean Air Delivery Rate (CADR) is key to choosing the more effective system. CADR test results are expressed in cubic feet per minute (CFM), with a number rating for three “yardstick” pollutants: tobacco smoke, dust and pollen. The higher the CADR test numbers, the better the overall ability of the unit to clean your indoor air. CADR results reflect: – the size of the particle removed – what percentages of particles are removed – the volume of air actually moving through the system Air volume is often described as air exchange (the number of times the total volume of air in the room is processed by the unit within a given period of time). Some manufacturers substitute air exchange rates for CADR results, but they are not equivalent. CADR numbers give a much more precise report of an air purifier’s performance. CADR works the same way, rating not just how much air is cleaned nor ju
