Air Purifier Buyers Guide

Measure your room size to find the square footage.

Your air purifier will, at minimum, need a HEPA filter. Use your room size to find out the appropriate CADR minimum rating. You will find separate ratings for smoke (the smallest particles), dust (medium-size particles) and pollen (the largest particles).

Determine what types of filters you need. While you will get the best results from a purifier that uses a pre-filter, a HEPA filter and an activated carbon filter.  Look for a HEPA filter with a build in carbon filter.  A pre-filter is essential for larger pollutants like pet hair, and extends the life of your HEPA filter, and an activated carbon filter is essential for gases, VOCs, odors and the like. If you’re doing renovations or live in an area where wildfire smoke is a big concern, spring for the activated carbon — you’ll be happy you did.

Check the type of filter used. We recommend sticking with a HEPA filter that removes at least 99.97% of particles larger than or equal to 0.3 microns in diameter.

Check the decibel rating for the fan speeds. Air purifiers should operate below 30 decibels at the lowest fan speed so you can run them while you sleep. Also check the noise level at the highest speed. This is the speed at which the CADR rating is measured and will be the most efficient at cleaning the air. If your air quality is expected to be poor for an extended period of time, like with wildfires, the high fan speed sound level will be especially important. Anything over 50 decibels will make conversation difficult.

Think past the purchase. Things break and when they do can you get your air purifier repaired? Check to ensure there is a part-supported warranty.