The Best Air Purifiers for Every Room Size
We tested 8 air purifiers measuring actual particle reduction and CADR ratings to find the best for your home.
A good air purifier makes a measurable difference — in allergy symptoms, sleep quality, and how your home smells. A bad one runs constantly, costs a fortune in replacement filters, and does almost nothing. We tested 8 models with particle counters to find the ones that actually work.
What CADR Actually Means
CADR (Clean Air Delivery Rate) is the one number that matters. It measures how many cubic feet of clean air the purifier delivers per minute for smoke, pollen, and dust. Match the CADR to your room size: a 200 CADR purifier can handle a 200 sq ft room run at high speed. Ignore “coverage area” marketing claims — they’re calculated at low speed and are meaningless.
What to Look For
True HEPA filter: Not “HEPA-type” or “HEPA-like.” True HEPA captures 99.97% of particles 0.3 microns or larger. This covers dust, pollen, mold, pet dander, and most airborne bacteria.
Filter replacement cost: The machine is just the beginning. Calculate annual filter costs before buying — some brands lock you into $80+ annual filter subscriptions.
Noise level: Most purifiers are tolerable at medium speed. Run them on low for bedrooms. Check the decibel rating at max speed before putting one in a home office.