Blueair Blue Pure 511i Max Air Purifier: CADR, Noise, Coverage & Specs
Last verified: Aug 22, 2026
Aug 2026
Quick verdict
The Blueair Blue Pure 511i Max is best suited to medium rooms where high airflow, quiet minimum operation, and app control are priorities. Its 174 CFM smoke CADR supports about 270 sq ft at approximately 4.8 air changes per hour. Buyers should separately evaluate filter cost, maximum-speed noise, and Blueair’s HEPASilent filtration before deciding.
Best for
- Living rooms and medium bedrooms
- Low-noise minimum settings
- App or Wi-Fi control
Consider alternatives if
- You need a verified maximum-speed noise figure
- Filter replacement interval or cost is a deciding factor
Verified strengths
- 174 CFM smoke CADR (~270 sq ft at ~4.8 ACH)
- 19 dB published minimum noise
- HEPASilent filtration (as published)
- Wi-Fi or app control
Verified limitations or missing information
- Maximum-speed noise is not in our sources
- Filter replacement interval is not verified
Blueair Blue Pure 511i Max overview
The Blueair Blue Pure 511i Max is a medium-room air purifier with a smoke CADR of 174 CFM. Based on our CADR-based room-size method, it is suitable for approximately 270 sq ft. It includes HEPASilent filtration, 19 dB minimum noise, and Wi-Fi or app support.
- Smoke CADR
- 174 CFM
- Recommended room size
- 270 sq ft
- Claimed coverage
- 465 sq ft
- Minimum noise
- 19 dB
- Filter type
- HEPASilent
- Wi-Fi / app
- Yes
- Power
- 17 W
- Weight
- 4.2 lb
- Last verified
- Aug 22, 2026
Blueair Blue Pure 511i Max CADR and room size
Recommended room size is about 270 sq ft (CADR × 1.55). That is approximately 4.8 air changes per hour in a room with an eight-foot ceiling. The manufacturer figure of 465 sq ft corresponds to about 2.8 air changes per hour at the same ceiling height and is shown separately. Our recommended room size uses approximately 4.8 air changes per hour with an eight-foot ceiling. Manufacturer coverage figures may use a lower air-change rate and are shown separately.
Validated coverage from documentation is 465 sq ft.
Blueair Blue Pure 511i Max noise level
Published minimum noise is 19 dB.
Maximum-speed noise is not in our sources.
Blueair Blue Pure 511i Max filtration
Published filter type: HEPASilent.
Blueair describes HEPASilent as a combination of mechanical and electrostatic filtration. We do not independently verify particle-removal efficiency.
Filter replacement interval is not verified in our sources.
Blueair Blue Pure 511i Max smart features
Wi-Fi capability, Smart sensor, Auto mode, Night mode
Blueair Blue Pure 511i Max specifications
- CADR (smoke)
- 174 CFM
- Recommended room size
- 270 sq ft
- Validated coverage
- 465 sq ft
- Manufacturer claimed coverage
- 465 sq ft
- Minimum noise
- 19 dB
- Filter type
- HEPASilent
- Power
- 17 W
- Weight
- 4.2 lb
- Wi-Fi / app
- Yes
About Blueair air purifiers
Blueair models in this catalog are compared by CADR, recommended room size, noise, and filter type.
Blueair Blue Pure 511i Max comparisons
Compared with the Blueair Blue Signature Small, the Blueair Blue Pure 511i Max has 9% higher CADR.
What is the CADR of the Blueair Blue Pure 511i Max?
Smoke CADR is 174 CFM.
What room size is the Blueair Blue Pure 511i Max suitable for?
About 270 sq ft at approximately 4.8 air changes per hour with an eight-foot ceiling.
How loud is the Blueair Blue Pure 511i Max?
Minimum reported noise: 19 dB.
Does the Blueair Blue Pure 511i Max have Wi-Fi?
Yes — app or Wi-Fi features are listed.
What filter does the Blueair Blue Pure 511i Max use?
HEPASilent.
Methodology
Specifications are compiled from manufacturer documentation, product listings and other cited sources.
How we calculate recommended room size.
Sources
All air purifiers · Blueair air purifiers · Best air purifiers for allergies · Methodology