Blueair Blue Pure 211i Max Review: CADR, HEPASilent, Ozone and Alternatives

The Blueair Blue Pure 211i Max is a large-room purifier for a living room, open-plan space or big bedroom up to about 674 sq ft. Blueair rates it at 435 cfm of smoke CADR, ENERGY STAR confirms a near-identical figure, and it draws only 46 W at full speed. The trade-off is HEPASilent: the filter is helped by electrostatic charging that you can’t switch off, so CARB lists it as an electronic air cleaner. We’d buy it for a big room if a small, documented ozone reading doesn’t bother you; if it does, look at a mechanical-only model instead.

This review is research-based, not a test of our own. Every number below comes from Blueair’s product pages, the ENERGY STAR Version 3.0 data set and the CARB certified list. Blueair isn’t in the AHAM Verifide directory, so the CADR figures are Blueair’s own, cross-checked against ENERGY STAR. Our research method explains how we work.

Blueair 211i Max specs at a glance

Spec	Blueair Blue Pure 211i Max	Source
CADR (smoke / dust / pollen)	435 / 452 / 450 cfm (Blueair); 443 / 457 / 450 cfm (ENERGY STAR)	Blueair, ENERGY STAR
Room size	674 sq ft at 4.8 air changes per hour (Blueair); 687 sq ft (ENERGY STAR)	Blueair, ENERGY STAR
Filter	One cylindrical filter: washable fabric pre-filter, particle media, carbon layer	Blueair
Technology	HEPASilent (electrostatic charging plus filter media)	Blueair
CARB	Certified (SKU 3613111100, Electronic, EO G-23-076)	CARB
Ozone	2 ppb	ENERGY STAR
Noise	23 to 53 dB	Blueair
Power	46 W max	Blueair
ENERGY STAR	Yes (V3.0, 10.14 smoke CADR/W, 259 kWh/yr)	ENERGY STAR
Smart features	Wi-Fi, Blueair app, Alexa and Google Home, PM1/PM2.5/PM10 sensing, Auto and Night modes, 4 speeds	Blueair

How much air does the 211i Max clean?

Blueair rates it at 435 cfm for smoke, 452 for dust and 450 for pollen. ENERGY STAR’s record for the same SKU is slightly higher at 443 smoke and 457 dust. The two sources are close enough that it doesn’t change the buying decision; we use Blueair’s numbers in this review and say so when we use ENERGY STAR’s.

Blueair’s 674 sq ft matches AHAM’s own formula (smoke CADR x 1.55), which works out to about 4.8 air changes per hour in a room with an 8 ft ceiling. AHAM’s simpler rule of thumb, a smoke CADR of at least two-thirds of the floor area, puts the ceiling at roughly 650 sq ft. Think a 20 x 30 ft living room or an open kitchen and family room. For wildfire smoke, AHAM suggests a smoke CADR equal to the room’s square footage, which would cap the 211i Max at about 435 sq ft.

One detail worth knowing: under AHAM’s AC-1-2020 test method, 450 cfm is the highest pollen CADR the test can measure. The 211i Max sits right at that ceiling for pollen.

Ignore the 3,235 sq ft figure on Blueair’s page. It assumes one air change per hour and can’t be compared with 4.8-ACH room sizes from other brands. To check your own room, use our air purifier size calculator, and read what CADR is for how the test works. Like every CADR, these numbers are measured at top speed; on Night mode it cleans less air.

HEPASilent, electrostatic charging and ozone

HEPASilent is Blueair’s name for combining electrostatic charging with mechanical filter media. It’s the reason the 211i Max is grouped with ionizing purifiers in the regulators’ lists, even though it has no separate ionizer button.

The cost is that it counts as an electronic air cleaner. CARB certifies the 211i Max (SKU 3613111100, EO G-23-076, April 2023) as electronic, which means it emits no more than 0.050 ppm (50 ppb) of ozone. ENERGY STAR, which also caps ozone at 50 ppb for certified models, lists a measured 2 ppb. That’s a small number, but it isn’t zero, and Blueair documents no button or setting to switch the charging off.

EPA notes that air cleaners using ionizers or electrostatic precipitators may emit ozone, a lung irritant. HEPASilent isn’t exactly either, but CARB puts it in the same electronic group. In our view the 211i Max’s documented reading is low, but if anyone in the home is sensitive to ozone, we’d choose a mechanical-only purifier. Our guides to the ionic air purifier and air purifier side effects explain the background.

Don’t read the HEPASilent name as a True HEPA claim either. The US DOE defines HEPA as a filter tested at 99.97% efficiency at 0.3 µm, and none of the sources we rely on give such a figure for the 211i Max. What counts for comparison is the CADR, and that’s both published and cross-checked.

Filters: what’s inside and what they cost

The 211i Max uses one cylindrical filter with a particle layer and a carbon layer, wrapped in a fabric pre-filter. Blueair says to replace the main filter up to every 9 months and sells three versions:

• Particle + Carbon (#110039), the standard filter for light household odors, around $70
• SmokeBlock (#111234), with “2x more activated carbon” per Blueair, around $85
• AllergenBlock (#111226), around $90

Replacement fabric pre-filters cost around $13. The pre-filter is the only washable part; the main filter can’t be washed.

Blueair publishes no carbon weight for any of these. EPA notes that thin carbon layers saturate quickly, so the standard filter is for everyday cooking and household smells, not heavy smoke odor or VOCs. If smoke is the main reason you’re buying, get the SmokeBlock filter, and see our HEPA vs carbon filter guide for why carbon amount matters.

Noise, controls and running cost

Blueair rates the 211i Max at 23 dB on its lowest setting and 53 dB at the top of its four speeds. Sensors read PM1, PM2.5 and PM10 and drive Auto mode; Night mode is there for bedrooms. You can control it through the Blueair app or with Alexa and Google Home.

Power is where it stands out. Blueair lists 46 W at maximum, and ENERGY STAR rates it at 10.14 smoke CADR per watt with an estimated 259 kWh a year. At the US average of 18.31 cents per kWh (EIA, July 2026), ENERGY STAR’s estimate works out to about $47 a year. Running flat out at 46 W around the clock would be about 403 kWh and roughly $74 a year by our math; eight hours a night at top speed would be about $25. Try your own hours and rate in the air purifier electricity cost calculator.

Add the filters, and at Blueair’s 9-month interval the standard filter adds roughly $90 to $95 a year.

Blueair 211i Max vs 311i Max, Blue Signature and Coway Airmega 400

	211i Max	311i Max	Blue Signature (Large)	Coway Airmega 400
Smoke CADR	435 (Blueair)	283 (Blueair)	455 (Blueair)	376 (ENERGY STAR)
Room size	674 sq ft	439 sq ft	705 sq ft	583 sq ft
Max power	46 W	32 W	42 W	66 W
Ozone tech	Electrostatic (CARB electronic)	Electrostatic (CARB electronic)	Electrostatic (CARB electronic)	None (CARB mechanical)
Filter life	Up to 9 months	Up to 9 months	Up to 1 year	6 to 12 months (Coway)

Blueair Blue Pure 211i Max

The 211i Max is the one to get for a large room when you want high CADR on very little power and an app. You get a CADR that ENERGY STAR backs up, a washable fabric pre-filter, PM1 to PM10 sensing and four speeds, at around $350. The trade-offs are electrostatic charging you can’t turn off, a 9-month filter interval and no published carbon weight.

Blueair Blue Pure 311i Max

The 311i Max uses the same design at a smaller scale. Blueair lists 283 smoke, 314 dust and 365 pollen CADR for 439 sq ft, matching ENERGY STAR’s record. It draws 32 W at max, is ENERGY STAR certified (193 kWh a year) and is rated at 23 to 50 dB. It has Wi-Fi, the Blueair app, Auto and Night modes and three speeds. Filters are around $45 and last up to 9 months; the unit is around $230.

It shares the 211i Max’s caveat: CARB lists it as electronic (EO G-23-050) and ENERGY STAR measured 2 ppb of ozone. We’d pick it for a bedroom or a medium living room under about 430 sq ft. Blueair also sells a higher-output 311i+ Max (339 smoke CADR, 525 sq ft per ENERGY STAR) for rooms in between.

Blueair Blue Signature (Large)

The Blue Signature Large (SP4i) covers slightly more space: Blueair lists 455 smoke, 434 dust and 450 pollen CADR for 705 sq ft, again matching ENERGY STAR. It draws 3.5 to 42 W, scores 11.49 smoke CADR per watt and is rated at 23 to 55 dB. Its filter adds Blueair’s “OdorFence” carbon and lasts up to a year at around $100, and the unit doubles as a side table with a motion-activated display. It costs around $450.

It’s also CARB-listed as electronic (ENERGY STAR measured 3 ppb of ozone for the Large). Blueair’s “10x more odor removal” claim comes from its own comparison test, so we wouldn’t buy it on that alone. Medium (SP3i) and Small (SP1i) versions exist for smaller rooms.

Coway Airmega 400

If you want a big-room purifier without any ionizing or electrostatic stage, the Airmega 400 is the alternative we’d look at. ENERGY STAR lists 376 smoke, 384 dust and 409 pollen CADR for 583 sq ft (Coway’s own page shows lower figures), CARB lists it as mechanical and ENERGY STAR records 0.00 ppb of ozone. It has two washable pre-filters and two combined carbon and HEPA filters. The catches are price, around $650 for the 400 and $750 for the Wi-Fi 400S, and 66 W at max.

Who the 211i Max suits, and who should skip it

Good fit:

• A living room or open-plan space up to about 650 sq ft
• Anyone who wants low running costs on a large purifier
• Homes with pets, thanks to the washable fabric pre-filter; our best air purifier for pets guide compares more options

We’d skip it if:

• You don’t want any electrostatic or ionizing stage in the house (look at the Coway Airmega 400)
• Your room is under about 400 sq ft (the 311i Max costs less and uses less power)
• You need heavy odor or smoke removal on the standard filter; at minimum, switch to SmokeBlock

For more large-room options, see our guide to the best air purifier for a large room.

Note: An air purifier can reduce airborne allergens, dust and smoke particles, but it doesn’t replace removing the source or ventilating. If you’re buying for asthma or allergies, talk to your doctor about what else will help.

Our verdict

On paper, the Blueair Blue Pure 211i Max is one of the most efficient large-room purifiers you can buy: a 435 smoke CADR that ENERGY STAR confirms, about 674 sq ft of coverage, and only 46 W at full speed. The weak points are electrostatic charging with no off switch, which makes it a CARB electronic unit even though its measured ozone is low, a filter that lasts up to 9 months, and thin carbon in the standard filter. In our view it’s a strong buy for a big living space if you’re comfortable with that. If you’re not, we’d pay more for the mechanical-only Coway Airmega 400; if your room is smaller, the 311i Max is the better-value Blueair.