Functionality

The AirDoctor purifier is large enough to filter the air in a 2,400-square-foot room once every hour, so that should accommodate all except the largest spaces. This heavy-duty unit is designed to run for long periods of time. Exactly how long it can purify air for effectively depends on the size of the space and its air quality to start with. According to the manufacturer, the AirDoctor's Gas Trap VOC filter should last approximately six months if running 24/7 and its UltraHEPA filter should last about 12 months. If your purifier is running less, these filters will last longer.

The unit is backed by a one-year limited warranty. This does not include the filters. It also includes automatic settings that can turn the purifier on and adjust the speeds as necessary to maintain optimal air quality without overworking the purifier and sensors that let you know when the filters need to be changed.

Filtration and CADR ratings

Air purifiers have three CADR ratings that indicate how well it does at filtering out various contaminants with a higher rating indicating that the purifier does a better job of filtering out that particular contaminant. The AirDoctor has a 326 rating for smoke, a 343 rating for dust and a 373 rating for pollen. These are higher ratings than you see with many other comparable air purifiers, so it's a good choice for homes with poor air quality or those who need a very clean environment.

The AirDoctor purifier includes an UltraHEPA filter. HEPA filters are designed to trap particles down to 0.3 microns, and they're usually held up as the standard for high-quality air filtration. But the UltraHEPA filter traps particles down to 0.003 microns -- that's 100 times smaller than the typical HEPA filter. So for the AirDoctor and the IQ Air, they capture particles as small as 0.003 microns, as compared to the Germ Guardian that captures particles ay 0.3 microns. The AirDoctor backs all of this up with an air ionizer, which you can turn on and off at your own convenience. This can also help remove particles from the air and it can also eliminate odors, leaving the room smelling fresher.

Manufacturer reliability and customer service

AirDoctor maintains an A+ rating with the Better Business Bureau and it stands by its product with a one-year limited warranty. If you experience any issues with the purifier or you have any questions, you can reach out to the company six days per week via phone or at any time via email. You can also view a copy of the purifier's manual on its website, which should address some of the most common concerns. AirDoctor also qualifies as an Energy Star certified appliance.