Blueair Blue Pure Max Series: Which Model Clears a Large Room Fast and Stays Quiet?
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The short answer: The Blue Pure 211i Max is the top pick for large rooms: its 435 CFM CADR and 674 sq ft coverage clear more space per minute than any other model here, and it runs at 23 dB on low. If you want most of that airflow for less, the 311i+ Max delivers 339 CFM and 525 sq ft coverage for $95.00 less, while the 311i Max is the value step-down at $229.99.
- Best overall: Blue Pure 211i Max — 435 CFM CADR and 674 sq ft coverage are the highest in the family, and it still runs at 23 dB on low. See price at blueair.com
- Best value: Blue Pure 311i+ Max — 339 CFM CADR and 525 sq ft coverage for $254.99, $95.00 less than the 211i Max, with the same 23 dB low setting. See price at blueair.com
- Best for mid size rooms: Blue Pure 311i Max — 283 CFM CADR and 439 sq ft coverage at $229.99, $25.00 less than the 311i+ Max, in a 7.8 lb body. See price at blueair.com
- Best compact: Blue Pure 511i Max — 153 CFM CADR and 237 sq ft coverage at 19 dB on low, weighing 4.2 lb and costing $139.99. See price at blueair.com
| Product | cadr | coverage sqft | noise db | dimensions | weight | Price now | 90-day low | Rating | |
|---|---|---|---|---|---|---|---|---|---|
| Blue Pure 211i Max | 435 CFM | 674 sq ft | 23 dB | 22.7 x 14.4 x 14.4 | 16.2 lb | $349.99 | — | 4.6 | blueair.com |
| Blue Pure 311i Max | 283 CFM | 439 sq ft | 23 dB | 19 x 12.5 x 12.5 | 7.8 lb | $229.99 | — | 4.6 | blueair.com |
| Blue Pure 311i+ Max | 339 CFM | 525 sq ft | 23 dB | 21 x 12.5 x 12.5 | 7.9 lb | $254.99 | — | 4.6 | blueair.com |
| Blue Pure 411i+ Max | 167 CFM | 259 sq ft | 19 dB | 18.9” x 10.6” x 10.6” | — | $144.49 | — | 5.0 | blueair.com |
| Blue Pure 511 | 122 CFM | 189 sq ft | 24 dB | 13.4” x 7.9” x 7.9” | 4.2 lb | $99.99 | — | 4.2 | blueair.com |
| Blue Pure 511i Max | 153 CFM | 237 sq ft | 19 dB | 14.5” x 9.3” x 9.3” | 4.2 lb | $139.99 | — | 4.6 | blueair.com |
Blue Pure 211i Max
Pros
- 435 CFM CADR, the highest airflow in the lineup, for fast clearing of large rooms
- 674 sq ft coverage, the largest here
- Runs at 23 dB on low, quiet for its airflow
- Rated 4.6
Cons
- At $349.99 it costs $120.00 more than the Blue Pure 311i Max and $95.00 more than the 311i+ Max
- 16.2 lb, the heaviest of the listed models
Who it's for: Anyone who needs to clear a large room quickly and will pay the lineup's top price for maximum airflow and coverage.
Blue Pure 311i Max
Pros
- 283 CFM CADR and 439 sq ft coverage for fast air turnover in a large room
- Runs at 23 dB, quiet enough for low-speed use in a bedroom or office
- Weighs 7.8 lb and measures 19 x 12.5 x 12.5 in, easy to move between rooms
- Rated 4.6 by users
Cons
- At $229.99 it costs $25.00 less than the 311i+ Max, which offers higher CADR (339 CFM) and coverage (525 sq ft)
- Lower CADR and coverage than the 211i Max, which is $120.00 more
Who it's for: Buyers who want a quiet, lightweight purifier for a large room and will trade some airflow for a lower price than the 311i+ Max.
Blue Pure 311i+ Max
Pros
- 339 CFM CADR and 525 sq ft coverage clear a large room quickly
- Runs at 23 dB on low, so it stays quiet while you sleep or work
- At $254.99 it costs $25.00 more than the Blue Pure 311i Max and $95.00 less than the Blue Pure 211i Max
- Rated 4.6 by users
Cons
- At 7.9 lb and 21 x 12.5 x 12.5 in, it is larger and heavier than the 7.8 lb Blue Pure 311i Max
- Lower CADR and coverage than the Blue Pure 211i Max's 435 CFM and 674 sq ft
Who it's for: Buyers who want strong large-room airflow with quiet low-speed operation and a mid-range price.
Blue Pure 411i+ Max
Blue Pure 511
Blue Pure 511i Max
Pros
- 19 dB noise rating matches the quietest units in the lineup
- 153 CFM CADR and 237 sq ft coverage in a 4.2 lb, 14.5 x 9.3 x 9.3 in body
- Rated 4.6, and at $139.99 it costs $40.00 more than the Blue Pure 511 and $4.50 less than the Blue Pure 411i+ Max
Cons
- 153 CFM CADR is the second-lowest here, well under the 435 CFM Blue Pure 211i Max
- 237 sq ft coverage is smaller than the 439-674 sq ft of the 311i Max, 311i+ Max and 211i Max
Who it's for: Buyers who want a compact, very quiet purifier for a small room and don't need the airflow of the larger Blue Pure Max models.
How we chose
How we chose
We lined up the six Blue Pure Max models and compared the numbers that decide whether a purifier actually suits a room: CADR in CFM, coverage in sq ft, noise on low in dB, and the current price. Every model here carries a 4.6 rating except the Blue Pure 411i+ Max at 5.0 and the Blue Pure 511 at 4.2.
Airflow and coverage separate the family clearly. The Blue Pure 211i Max is rated 435 CFM and 674 sq ft, the Blue Pure 311i+ Max 339 CFM and 525 sq ft, the Blue Pure 311i Max 283 CFM and 439 sq ft, the Blue Pure 411i+ Max 167 CFM and 259 sq ft, the Blue Pure 511i Max 153 CFM and 237 sq ft, and the Blue Pure 511 122 CFM and 189 sq ft.
On quiet operation, the Blue Pure 411i+ Max and Blue Pure 511i Max are rated 19 dB, the Blue Pure 211i Max, 311i Max and 311i+ Max 23 dB, and the Blue Pure 511 24 dB. Current prices run from $99.99 for the Blue Pure 511 to $349.99 for the Blue Pure 211i Max, so we weighed each step up in airflow against the dollars it adds.
Who should skip these
Skip the Blue Pure 211i Max if your room is under roughly 500 sq ft. Its 674 sq ft coverage and 435 CFM are more than a smaller space needs, and the 311i+ Max covers 525 sq ft for $95.00 less.
Skip the Blue Pure 511 and the Blue Pure 511i Max if you need to clear a large room quickly. At 122 CFM and 189 sq ft, and 153 CFM and 237 sq ft respectively, neither moves air fast enough for that job.
If your room is small, the 411i+ Max covers 259 sq ft at 167 CFM for $144.49, and the 511 covers 189 sq ft for $99.99. Both are sized for a single room rather than a whole floor.
How to choose the right one
Start with coverage. Each model lists the square footage it is rated for, so match that number to the room you actually need to clean: 674 sq ft for the Blue Pure 211i Max, 525 sq ft for the 311i+ Max, 439 sq ft for the 311i Max, 259 sq ft for the 411i+ Max, 237 sq ft for the 511i Max, and 189 sq ft for the 511.
Then look at CADR, which tells you how quickly the unit moves cleaned air: 435 CFM on the 211i Max, 339 CFM on the 311i+ Max, 283 CFM on the 311i Max, 167 CFM on the 411i+ Max, 153 CFM on the 511i Max, and 122 CFM on the 511. For a bedroom, check the low-setting noise figure, since that is what you will hear overnight: 23 dB on the 211i Max, 311i Max, and 311i+ Max, 19 dB on the 411i+ Max and 511i Max, and 24 dB on the 511.
Price separates them. The 211i Max costs $120.00 more than the 311i Max and $95.00 more than the 311i+ Max. The 311i+ Max costs $25.00 more than the 311i Max, which costs $90.00 more than the 511i Max and $130.00 more than the 511.
Questions readers ask
Which model clears a large room fastest?
The Blue Pure 211i Max has the highest CADR at 435 CFM and covers up to 674 sq ft, the largest figures in this family.
Which models run quietly on low?
The Blue Pure 411i+ Max and Blue Pure 511i Max are rated 19 dB, while the 211i Max, 311i Max and 311i+ Max are rated 23 dB.
How much more does the 211i Max cost than the others?
It costs $120.00 more than the 311i Max, $95.00 more than the 311i+ Max, $205.50 more than the 411i+ Max, $250.00 more than the 511 and $210.00 more than the 511i Max.
What is the price difference between the 311i Max and 311i+ Max?
The 311i+ Max costs $25.00 more than the 311i Max.
Which is the lightest option?
The Blue Pure 511 and Blue Pure 511i Max both weigh 4.2 lb, the lightest in the family.
Update history
- — First published
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