Blueair Blue Pure 211i Max vs Windmill Windmill Air Purifier (975 sq ft model)
Windmill Windmill Air Purifier (975 sq ft model)
The short answer
Blueair Blue Pure 211i Max comes out ahead overall with 7.4/10 against 6.8/10 for the Windmill Windmill Air Purifier (975 sq ft model). Blueair Blue Pure 211i Max is stronger on cleaning performance for bedroom size, running cost & ownership and value. Windmill Windmill Air Purifier (975 sq ft model) is stronger on sleep-friendly features and indoor-air safety & materials. At current verified prices, the Windmill Windmill Air Purifier (975 sq ft model) costs about $110.99 less.
- Choose the Blueair Blue Pure 211i Max if: Owners of a large primary suite who want high CADR at night without an always-on ionizer, for about $90 less than the SP4i.
- Choose the Windmill Windmill Air Purifier (975 sq ft model) if: Sleepers who want built-in white noise and a minimalist design for a small bedroom.
Scores by criterion
| Criterion | Blueair Blue Pure 211i Max | Windmill Windmill Air Purifier (975 sq ft model) |
|---|---|---|
| Noise at sleep-usable speeds | 7.3RTINGS snippet: 33.9 dBA on low; no measured airflow below 45 dB. | 7.5Tom's Guide: 38.4 dBA on low. |
| Cleaning performance for bedroom size | 8.5435 smoke CADR rated. | 5.0130 cfm, 202 sq ft. |
| Sleep-friendly features | 8.0Night mode with dimmed lights, auto, app. | 8.8Whisper mode with lights off, White Noise mode, app. |
| Indoor-air safety & materials | 7.0Zero-ozone verified and CARB; HEPASilent uses electrostatic charging. | 8.0No ionizer; AHAM Verifide, CARB, Energy Star listed. |
| Running cost & ownership | 6.546 W; filters last about 9 months. | 5.0Proprietary 6-month filters. |
| Value | 6.5$349. | 6.0$189 from a third-party seller on Amazon. |
Specifications
| Spec | Blueair Blue Pure 211i Max | Windmill Windmill Air Purifier (975 sq ft model) |
|---|---|---|
| Workflow type | Extra Large Room | — |
| Lowest-speed noise (manufacturer) | 23 dB | 16 dB |
| Top-speed noise (manufacturer) | 53 dB | 52 dB |
| Lowest-speed noise (independent measurement) | 33.9 dBA | 38.4 dBA |
| CADR (smoke where given, else headline) | 435 cfm | 130 cfm |
| Recommended room size (4.8–5 ACH / AHAM) | 674 sq ft | 202 sq ft |
| Max power draw | 46 W | — |
| Sleep / night mode | Yes | Yes |
| App control | Yes | Yes |
| Ionizer / electrostatic stage | HEPASilent (electrostatic charging + mechanical filtration) | None mentioned |
| Filter type | HEPASilent particle + carbon filter, washable fabric pre-filter | 3-in-1 H13 HEPA with activated carbon layer (proprietary) |
| Main filter life | 9 months | 6 months |
| Quiet Mark certified | Yes | — |
Blueair Blue Pure 211i Max
Pros
- Large CADR headroom
- Night mode with dimmed lights
- Zero Ozone Verified per retailers
- Cheaper than the SP4i
- App control
Cons
- Limited independent noise testing
- Oversized for small rooms
- Loud at max, about 58.7 dBA
- Premium price
A sensible big-room alternative to the SP4i if you want to skip the unswitchable ionizer and save some money.
Full Blueair Blue Pure 211i Max review →Windmill Windmill Air Purifier (975 sq ft model)
Pros
- White Noise mode
- Lights-off Whisper mode
- Minimalist design
- App control
- Multiple certifications listed
Cons
- Modest 130 cfm CADR
- Filters every six months
- Among the costliest to own
- Amazon offer is third-party
A design and sleep-sound pick, not a performance pick. Buy it for the look and the white noise.
Full Windmill Windmill Air Purifier (975 sq ft model) review →Both products are part of our guide The Best Quiet Air Purifiers for Bedrooms of 2026, where you can see every pick, how we score and current prices from each retailer.