Blueair Blue Pure 211i Max Review
The most capable machine we cover on raw numbers, and the one with the most interesting asterisk. We do not test units; here is what the two registers say.
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The most capable machine we cover on raw numbers: 435 certified smoke CADR across 674 certified square feet at 9.0 CFM per watt, which is the best air-per-watt figure on this site by a clear margin. The asterisk is 2 ppb of measured ozone and an ion stage the two registers describe differently.
To be clear before anything else: we have not tested this unit. We own no air purifiers and run no laboratory. What follows is the certified record, which for this machine is unusually complete because it is one of the few models listed in both registers — our method, including where it runs out.
The certified record
| Specification | Figure | Source |
|---|---|---|
| Smoke CADR | 435 CFM | AHAM VERIFIDE |
| Dust CADR | 453 CFM | AHAM VERIFIDE |
| Pollen CADR | 450 CFM | AHAM VERIFIDE |
| PM2.5 CADR | 444 CFM | AHAM VERIFIDE |
| Certified room size | 674 sq ft | AHAM, at 4.8 ACH |
| Annual energy use | 256 kWh | AHAM |
| Electricity per year | $47 | Our arithmetic at a named rate |
| Power draw | 44 W | AHAM |
| Air per watt | 9.0 CFM/W | AHAM |
| Measured ozone | 2 ppb | ENERGY STAR |
| Technology (AHAM) | Fan Filter with Ion Generator | AHAM VERIFIDE |
| Technology (ENERGY STAR) | Fan and Filter | ENERGY STAR |
| Filter classification | HEPA-Type | ENERGY STAR |
| Noise | Not published in our sources | — |
| Filter interval and price | Not published in our sources | — |
Electricity costs on this page use 18.34¢ per kWh, the U.S. average residential price for June 2026 from the U.S. Energy Information Administration, Electric Power Monthly, Table 5.3. Your rate is on your bill and is probably not this one; multiply the kWh figure by your own rate and you have your number.
The number that makes it interesting
9.0 CFM per watt is the highest Integrated Energy Factor of any machine on this site, and the gap is not marginal. The LEVOIT Core 600S, its nearest rival on coverage, manages 6.0. The Coway Airmega 400 manages 6.1. The Whirlpool Whispure manages 3.0.
In practical terms the 211i Max certifies 674 square feet on 256 kWh a year, while the Core 600S certifies 606 on 387. That is 11% more coverage for a third less electricity — $47 against $71 a year. Over the life of a machine that runs continuously, this is the strongest single argument for it.
The asterisk, in detail
AHAM’s directory classifies this model “Fan Filter with Ion Generator”. EPA’s ENERGY STAR database classifies the same model number “Fan and Filter” and publishes a measured ozone emission of 2 ppb.
Both of those cannot be a complete description of the same machine, and we are not in a position to adjudicate between two certification bodies. What we can say is what each publishes, which is why both rows are in the table above.
Two parts per billion is a small figure — the program limit is 50, and several machines we cover measure higher. It is also not the 0.00 ppb that the Honeywells, the LEVOIT Core range, the Coway Airmega 400 and the Medify MA-40 all return. EPA advises avoiding portable air cleaners that intentionally produce ozone because ozone is a lung irritant, and Blueair does not document a way to switch this stage off.
What Blueair does not publish
Two gaps, both of which competitors fill. Blueair publishes no noise figure we could source for this model, which matters for a machine that may end up in a room people sit in all evening — LEVOIT publishes a dB range for every Core unit. And it publishes no filter interval or replacement price we could source, which is half the running cost unbudgeted.
We print “Not published” rather than estimating either, and the absence is worth weighing against a machine that does publish them.
Quick picks
The 211i Max against the two machines a buyer at this size should weigh it against.
| # | Product | Best for | Certified CADR | Price |
|---|---|---|---|---|
| 1 |  The unit reviewed Blueair Blue Pure 211i Max 435 certified CFM across 674 sq ft at 9.0 CFM per watt. | Open-plan spaces above 500 sq ft | 435CFM smoke AHAM VERIFIDE | |
| 2 |  If ozone decides it Coway Airmega 400 376 certified CFM with 0.00 ppb measured and no ion stage. | Large rooms, verified Coway | 376CFM smoke ENERGY STAR verified | |
| 3 |  If the room is smaller Blueair Blue Pure 311i Max 283 certified CFM across 439 sq ft on 29.6 watts. | Mid-size rooms on a small electricity bill | 283CFM smoke AHAM VERIFIDE |
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The alternatives worth weighing
Coway Airmega 400
Coway · model Airmega 400 (AP-2015F)
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The Coway that is actually in a certification register: 376 certified smoke CADR, 583 square feet, zero measured ozone. If you want a Coway, this is the one with third-party numbers.
376 smoke / 384 dust / 409 pollen CFM · 380 PM2.5
- Certified room size
- 583 sq ft
- Energy / year
- 366 kWh
- Electricity / year
- $67
- Air per watt
- 6.1 CFM/W
- Noise
- Not published
- Measured ozone
- 0 ppb
- Filter class
- Composite Filter
- AHAM rule, 500 sq ft
- Clears it (334 needed)
No ionizer — filtration only
ENERGY STAR classifies this unit 'Fan and Filter', 0.00 ppb measured ozone.
376 certified smoke CADR across 583 certified square feet with 0.00 ppb measured ozone, no ion generator, and a real activated carbon layer the Blueair does not document. The two compared in full.
The honest con: 16% less air across 16% less room for $67 a year against $47 — you pay more to move less. ENERGY STAR also declines to classify its filter HEPA or HEPA-Type at all.
Blueair Blue Pure 311i Max
Blueair · model 3332111100 (Blue Pure 311i Max)
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439 certified square feet on under 30 watts. The best power-to-coverage ratio at mid size, with the same ion-generator caveat as the rest of the Max range.
283 smoke / 314 dust / 365 pollen CFM · 298 PM2.5
- Certified room size
- 439 sq ft
- Energy / year
- 193 kWh
- Electricity / year
- $35
- Air per watt
- 8.4 CFM/W
- Power draw
- 29.6 W
- Noise
- Not published
- Measured ozone
- 2 ppb
- Filter class
- HEPA-Type
- AHAM rule, 400 sq ft
- Clears it (267 needed)
Ion generator — fitted
AHAM classifies this model 'Fan Filter with Ion Generator'; ENERGY STAR records 'Fan and Filter' with 2 ppb measured ozone.
The same design at the next size down: 283 certified smoke CADR across 439 certified square feet on 29.6 watts, at 8.4 CFM per watt and $35 a year. Its certified pollen CADR of 365 is 29% above its own smoke figure, the largest such gap we have measured.
The honest con: identical ion-stage and 2 ppb position to the 211i Max, so it solves the room-size question and not the ozone one.
Common questions
Is the Blueair 211i Max worth it?
Does the Blueair 211i Max produce ozone?
What room size is the Blueair 211i Max good for?
Is the 211i Max better than the 311i Max?
Sources
- AHAM VERIFIDE directory of certified room air cleaners
- ENERGY STAR certified room air cleaners database
- EPA — Guide to Air Cleaners in the Home
Figures were read on the dates shown against each source. If one has changed, or if we have got something wrong, tell us and we will correct the page.
Read next
- Room sizeThe Best Air Purifiers for Large RoomsCertified for 500+ square feet, ranked on real coverage and what each costs to run.
- CADR & costBlueair vs LEVOITBlueair wins air-per-watt by a distance. Every Blueair here also has an ion stage and a measured ozone figure; every LEVOIT reads 0.00.
- CADR & costCoway Airmega 400 vs Blueair Blue Pure 211i Max435 CFM across 674 sq ft at 9.0 CFM/W against 376 across 583 at 6.1 — and 2 ppb measured ozone against 0.00.