Blueair Blue Pure 211i Max vs Blueair Blue Pure 311i Max

Blueair Blue Pure 311i Max for bedrooms, offices and normal-sized living rooms up to about 439 sq ft: it is cheaper, draws just 7.8 W and has identical filtration and sensing. Blueair Blue Pure 211i Max only when the space is bigger, since its 435 CFM smoke CADR and 674 sq ft rating are the sole meaningful upgrade.

Size and airflow. Blueair Blue Pure 211i Max is rated at 435 CFM smoke CADR for 674 sq ft and draws 46 W; Blueair Blue Pure 311i Max is rated at 283 CFM for 439 sq ft and draws 7.8 W. Filtration, the PM1, PM2.5 and PM10 sensors, the app, the certifications and the feature set are the same.

Yes, and that is unusual at this price. Both Blueair Blue Pure 211i Max and Blueair Blue Pure 311i Max separate the three particle sizes on the unit's display and in the Blueair app, instead of collapsing everything into a single colour indicator. Neither senses VOCs, CO2 or formaldehyde.

No. Both units use HEPASilent, which charges particles electrostatically before a mechanical filter catches them, rather than forcing air through a dense HEPA membrane. The benefit is much lower airflow resistance, which is how Blueair reaches high clean air delivery rates while staying quiet at moderate speeds.

Both are Energy Star certified and both use a washable pre-filter with a main filter rated at 9 months, tracked by the app. Blueair Blue Pure 311i Max is the cheaper one to keep running at 7.8 W against 46 W, though the larger machine is moving substantially more air for that power.