If you are buying an air purifier then an important metric to consider if the CADR or Clean Air Delivery Rate. But what does this describe?
CADR is a metric that is specifically used for home (residential) air purifiers, so it shouldn’t come as a surprise if you haven’t seen it before.
CADR measures the amount of air — in volume, specifically cubic feet per minute (CFM) — that is filtered by air purifier.
CADR isn’t simply CFM though because the measurement takes into account different sizes and types of particles, for instance dust, pollen, and smoke. A CADR rated air purifier will have separate CADR measurements for each type of particle.