Head to head

Alen BreatheSmart 75i Large Room Air Purifier vs Blueair Blue Pure 211+ Auto

Blueair Blue Pure 211+ Auto leads 3 to 2 on the 5 rankable specs and costs $410 less, which makes it the straightforward pick.

Catalog as of September 1, 2026

Why, in numbers

CADR: Alen BreatheSmart 75i Large Room Air Purifier lists 350 CFM across Smoke, Dust, Pollen (Alen sheet, 2026-09-02); Blueair Blue Pure 211+ Auto lists 353 CFM (Smoke), 347 CFM (Dust), 380 CFM (Pollen) (Blueair sheet, 2026-09-02).
Coverage area: Alen BreatheSmart 75i Large Room Air Purifier lists 1,400 sq ft (2 air changes/hr) / 700 sq ft (4 air changes/hr) (Alen sheet, 2026-09-02); Blueair Blue Pure 211+ Auto lists 550 sq ft (4.8 air changes/hr) / 1,320 sq ft (2 air changes/hr) (Blueair sheet, 2026-09-02).
Room size: Alen BreatheSmart 75i Large Room Air Purifier lists Large master suites, open living rooms, offices (Alen sheet, 2026-09-02); Blueair Blue Pure 211+ Auto lists Large living rooms, open floor plans, master suites (Blueair sheet, 2026-09-02).
Filter types: Alen BreatheSmart 75i Large Room Air Purifier lists Medical-grade H13 True HEPA + Antimicrobial layer + Heavy Odor Carbon (Alen sheet, 2026-09-02); Blueair Blue Pure 211+ Auto lists Washable fabric pre-filter + HEPASilent main filter (Particle + Carbon) (Blueair sheet, 2026-09-02).
Filter life: Alen BreatheSmart 75i Large Room Air Purifier lists 12–15 months extra long filter life (Alen sheet, 2026-09-02); Blueair Blue Pure 211+ Auto lists 6 months (Blueair sheet, 2026-09-02).

Manufacturer list price, not a live offer. Confirm current pricing before you buy.

Alen BreatheSmart 75i Large Room Air Purifier

$7492 spec wins

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Blueair Blue Pure 211+ Auto

$3393 spec wins

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Buying for

Every rankable spec counts once. Pick a lens to score only what matters for your air purifier.

Straight answer

Overall: 2 to 3

Buy the Blueair Blue Pure 211+ Auto.

Leads 3 of 5 rankable overall specs; Alen BreatheSmart 75i Large Room Air Purifier takes 2.
CADR: 353 CFM vs 350 CFM across Smoke, Dust, Pollen
Noise levels: 23 dB vs 25 dB
It is also $410 cheaper.

Check first: the Blueair Blue Pure 211+ Auto has no Wi-Fi app. the Blueair Blue Pure 211+ Auto has over 55 dB on high. the Blueair Blue Pure 211+ Auto has under 1,000 sq ft coverage. Tick them under deal-breakers if that rules it out.

2 Alen BreatheSmart 75i Large Room Air Purifier5 rankable of 11 specsBlueair Blue Pure 211+ Auto 3

Deal-breakers

tick what would make you walk away

No Wi-Fi approw
No schedules or remote control from your phone.
Clear:Alen BreatheSmart 75i Large Room Air Purifier · Alen Air AppTrips:Blueair Blue Pure 211+ Auto · One-touch Auto Mode
Over 55 dB on highrow
Louder than normal conversation at full speed.
Clear:Alen BreatheSmart 75i Large Room Air Purifier · 25 dB (WhisperMax) – 49 dB (Turbo speed)Trips:Blueair Blue Pure 211+ Auto · 23 dB (Low) – 56 dB (Turbo high)
Under 1,000 sq ft coveragerow
Undersized for an open-plan living area.
Clear:Alen BreatheSmart 75i Large Room Air Purifier · 1,400 sq ftTrips:Blueair Blue Pure 211+ Auto · 550 sq ft
Over 25 lb (11 kg)row
Hard to move between rooms.
Trips:Alen BreatheSmart 75i Large Room Air Purifier · 27.0 lbClear:Blueair Blue Pure 211+ Auto · 12.5 lb

At a glance

The handful of numbers that decide most purchases in this category.

2 of 2 differ

CADR

Alen

350 CFM across Smoke, Dust, Pollen

Blueair

353 CFM (Smoke), 347 CFM (Dust), 380 CFM (Pollen)

Coverage area

Alen

1,400 sq ft (2 air changes/hr) / 700 sq ft (4 air changes/hr)

Blueair

550 sq ft (4.8 air changes/hr) / 1,320 sq ft (2 air changes/hr)

True 3-Year Cost of Ownership (TCO)

Upfront price + 3 years of consumables, fees & essential add-ons

Alen BreatheSmart 75i Large Room Air Purifier

Upfront list price$749

3-Yr B6-Pure heavy HEPA filter (Every 12–15 months (~$99/yr))+$297

3-Year Estimated Total$1,046

Blueair Blue Pure 211+ Auto

Upfront list price$339

3-Yr Foldable Particle+Carbon filter (Every 6 months (~$45/yr))+$135

3-Year Estimated Total$474

The 90-Day Owner Regret Check

Documented ergonomic quirks, hardware annoyances, and maintenance realities reported by real owners.

Post-Purchase Truths

Alen: What to watch for

Maintenance
Requires periodic filter replacements to maintain airflow and odor capture.
Activated carbon and HEPA media gradually saturate, needing replacement once or twice yearly depending on air pollution and pet shedding.

Blueair: What to watch for

Maintenance
Requires periodic filter replacements to maintain airflow and odor capture.
Activated carbon and HEPA media gradually saturate, needing replacement once or twice yearly depending on air pollution and pet shedding.

Alen BreatheSmart 75i Large Room Air Purifier$7492 wins

Blueair Blue Pure 211+ Auto$3393 wins

Performance Filters Usability & Smart Design & Ownership

11 of 11 attributes differ. Identical rows are dimmed.

Performance

3 differences

Performance specifications. Middle column is Alen BreatheSmart 75i Large Room Air Purifier, right column is Blueair Blue Pure 211+ Auto.
CADR	350 CFM across Smoke, Dust, Pollen	353 CFM (Smoke), 347 CFM (Dust), 380 CFM (Pollen) (wins this row: higher)
Room size	Large master suites, open living rooms, offices	Large living rooms, open floor plans, master suites
Coverage area	1,400 sq ft (2 air changes/hr) / 700 sq ft (4 air changes/hr) (wins this row: higher)	550 sq ft (4.8 air changes/hr) / 1,320 sq ft (2 air changes/hr)

Filters

leads 1-0

Filters specifications. Middle column is Alen BreatheSmart 75i Large Room Air Purifier, right column is Blueair Blue Pure 211+ Auto.
Filter types	Medical-grade H13 True HEPA + Antimicrobial layer + Heavy Odor Carbon	Washable fabric pre-filter + HEPASilent main filter (Particle + Carbon)
Filter life	12–15 months extra long filter life (wins this row: higher)	6 months

Usability & Smart

leads 1-0

Usability & Smart specifications. Middle column is Alen BreatheSmart 75i Large Room Air Purifier, right column is Blueair Blue Pure 211+ Auto.
Noise levels	25 dB (WhisperMax) – 49 dB (Turbo speed)	23 dB (Low) – 56 dB (Turbo high) (wins this row: lower)
Energy consumption	45 W (Energy Star certified)	38 W max power consumption
Smart features	Alen Air App (Wi-Fi), auto modes, color ring status	One-touch Auto Mode (no Wi-Fi app)
Air quality sensors	Laser air quality sensor detecting fine particle levels with 5 color rings	Integrated particle sensor with 3-color air quality LED indicator

Design & Ownership

leads 1-0

Design & Ownership specifications. Middle column is Alen BreatheSmart 75i Large Room Air Purifier, right column is Blueair Blue Pure 211+ Auto.
Weight	27.0 lb (12.2 kg)	12.5 lb (5.7 kg) (wins this row: lower)
Warranty	Lifetime warranty (with active filter subscription)	2 years (with product registration)

Most rows are from the official spec sheet. Marked rows are other published figures or our summary, not lab tests we ran.

Alen BreatheSmart 75i Large Room Air Purifier source Blueair Blue Pure 211+ Auto source

Which one should you buy

Pick this one if

Alen BreatheSmart 75i Large Room Air Purifier

Commercial-grade quiet purifier cleaning up to 1,400 sq ft every 30 minutes with a lifetime warranty.

Industry-exclusive transferable Lifetime Warranty
Tuned pink noise frequencies promote deeper sleep on WhisperMax mode
Medical-grade H13 True HEPA filter lasts up to 15 months

What you give up

High initial investment
Tall tower profile

Full Alen BreatheSmart 75i Large Room Air Purifier specs →

Pick this one if

Blueair Blue Pure 211+ Auto

High-capacity large-room air purifier with 360-degree HEPASilent filtration and machine-washable fabric pre-filters.

High 353 CFM CADR cleans a 550 sq ft living room in just 12.5 minutes
HEPASilent electrostatic + mechanical filtration maximizes airflow and efficiency
Interchangeable washable fabric pre-filters in multiple designer colors

What you give up

No mobile app or Wi-Fi schedule controls (one-button operation)
Reaches 56 dB at highest turbo fan setting

Full Blueair Blue Pure 211+ Auto specs →

Best for each use

Bedrooms

Quiet nights: low-speed noise, sleep mode, schedules from your phone

For bedrooms, buy the Blueair Blue Pure 211+ Auto.

Leads 2 of 2 rankable bedrooms specs.
Noise levels: 23 dB vs 25 dB
Weight: 12.5 lb vs 27.0 lb
It is also $410 cheaper.

Big rooms & allergies

Open-plan rooms or allergies: CADR, coverage, filter grade

For big rooms & allergies, buy the Alen BreatheSmart 75i Large Room Air Purifier.

Leads 2 of 3 rankable big rooms & allergies specs; Blueair Blue Pure 211+ Auto takes 1.
Coverage area: 1,400 sq ft vs 550 sq ft
Filter life: 12–15 months extra long filter life vs 6 months
Blueair Blue Pure 211+ Auto is $410 cheaper. Pay the difference only if coverage area matters to you.

Low running cost

Cheap to own: filter life, power draw, warranty

Too close to call on low running cost from the spec sheets. Only filter life is rankable here.

Energy consumption: 45 W vs 38 W max power consumption
Warranty: Lifetime warranty vs 2 years

Every answer above is scored from published figures. A lens uses only the rows that matter for that use, including marked rows that are not on the official sheet. Switch lenses interactively in the panel above.

Done deciding?

Open the full standalone spec sheet for either device.

Alen BreatheSmart 75i Large Room Air Purifier spec sheet Blueair Blue Pure 211+ Auto spec sheet

Manufacturer pages: Alen BreatheSmart 75i Large Room Air Purifier ↗ · Blueair Blue Pure 211+ Auto ↗

Common questions

Which is cheaper, the Alen BreatheSmart 75i Large Room Air Purifier or the Blueair Blue Pure 211+ Auto?

Blueair Blue Pure 211+ Auto costs $410 less at list price.

What is the biggest catch with the Alen BreatheSmart 75i Large Room Air Purifier or Blueair Blue Pure 211+ Auto?

Blueair Blue Pure 211+ Auto has this deal-breaker: no Wi-Fi app. No schedules or remote control from your phone.

Which is better for bedrooms, the Alen BreatheSmart 75i Large Room Air Purifier or the Blueair Blue Pure 211+ Auto?

For bedrooms, buy the Blueair Blue Pure 211+ Auto. Leads 2 of 2 rankable bedrooms specs. Noise levels: 23 dB vs 25 dB

What cannot be compared from spec sheets?

Of the 11 specs tracked here, 6 are descriptive and cannot be ranked on numbers alone. Spec sheets also cannot measure subjective factors like build quality, real-world performance, or comfort.

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