Medify MA-40 Air Purifier with HEPA Filter | 1,793 ft² Coverage in 1hr for Smoke, Wildfires, Odors, Pollen, Pets | Quiet Removal to 0.3 Microns | White, 1-Pack

The Medify MA-40 has a CADR of 406 and costs about $250. Medify rates it for up to 896 sq ft in 30 minutes, or 1,793 sq ft in an hour. It has about 14,000 reviews at 4.6 stars.

Two things set it apart. The lifetime warranty (you have to register the unit) is the long-term selling point. The noise is the drawback.

The noise

It's loud. The quietest setting is 46 dB and the top speed is 66 dB. For comparison, the Levoit Core 300-P drops to 24 dB and the Blueair 211i Max to 23 dB. There is a sleep mode, but what it does is dim the lights. The 46 dB floor still applies.

So this isn't a bedroom purifier for light sleepers. It works better in a living room, a basement or a workshop, where some fan noise doesn't matter. Our quiet air purifier for sleeping roundup has the quieter options.

Filtration

It uses an H13 HEPA filter with a carbon layer. The listing claims 99.9% capture down to 0.1 micron. A replacement filter lasts about 3,000 hours, or roughly six months. Our how often to change an air purifier filter article covers filter timing, and HEPA filter air purifier explains the H13 grade.

Controls

There's a touch panel with three fan speeds, a 0-8 hour timer, a filter indicator and a child lock. There's no air quality sensor, no auto mode and no app. You pick a speed and it stays there. It is CARB compliant and ETL listed.

Who it's for

People with a large space who care more about coverage and warranty length than noise or smart features, and who plan to keep the unit for many years.

How it compares

The Blueair Blue Pure 211i Max has a similar CADR (about 410) and costs more, around $320 to $350. For that you get a sensor, auto mode, an app and a much quieter low setting (23 dB). If the purifier is going in a room where people sit or sleep, the Blueair is worth the extra.

The Winix 5510 has a lower smoke CADR (253) but costs about $135. It adds auto mode, an app and a 23.5 dB low setting. For a room of about 400 sq ft or less, it's the better value.

Our best air purifier for large rooms guide has the full large-room comparison.