Blueair Blue Signature Small vs Dreo Air Purifier 539S

The Blueair Blue Signature Small and Dreo Air Purifier 539S are evenly matched compact air purifiers, with both units providing near-identical clean air delivery rates. The Blueair is the better choice if you're looking for something with a subtler impact on your daily life; you can set small items on its flat top, and it runs noticeably quieter at both its highest and lowest fan speeds. That said, the Blueair features an always-on particle ionizer system. While said system's ozone production levels are certified to fall within safe limits, the Dreo might still be the better choice if that remains a risk factor for you or someone else in your household.