The catch
Levoit Core 400S-P
The current filter is not classed as HEPA-certified by RTINGS.
Side by side
Levoit Core 400S-P vs Blueair 311i Max: Core takes less floor space, Blueair brings more rated pollen airflow
Quick verdict
Pick the Blueair 311i Max if pollen airflow is the priority. The Levoit Core 400S-P suits a smaller floor space and stays clear of electrostatic charging.
Before you buy
Why, and what it costs you
Compare room sizes at an equal turnover rate
At five air changes per hour and an eight-foot ceiling, the numbers come to about 347 square feet for Levoit Core 400S-P and 425 for Blueair 311i Max.
Where this comes from
Area = CADR × 60 / (ceiling feet × air changes per hour). The inputs are 231 and 283 CFM, 8 feet and 5 changes, with smoke CADR used at maximum speed. In a real room, air mixing, furniture, open doors and filter loading matter too.
The catch
Blueair Blue Pure 311i Max
It isn't suitable if you insist on no ionizer, because HEPASilent leaves its ionization stage active.
Levoit Core 400S-P
- Why pick it
- A mechanical-only filter path is what you want
- The spot for it is narrow
- The catch
- The current filter is not classed as HEPA-certified by RTINGS.
Blueair Blue Pure 311i Max
- Why pick it
- Stronger pollen throughput is required
- Your routine works with a washable exterior prefilter
- The catch
- It isn't suitable if you insist on no ionizer, because HEPASilent leaves its ionization stage active.
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What this page compares
More pollen airflow points to the Blueair 311i Max. The Levoit Core 400S-P takes up less floor space and avoids electrostatic charging.
Pollen gives the wider cabinet a stronger case
Which one fits
Pick the situations that sound like you
The room is big enough to call for extra airflow
At the same five-change target and eight-foot ceiling, the calculated limit is 347 square feet for Levoit Core 400S-P and 425 for Blueair 311i Max. Give yourself margin if you want to run below maximum speed.
- Levoit Core 400S-P
- Depends
- Blueair Blue Pure 311i Max
- Better fit
The cabinet needs to fit next to furniture
Levoit Core 400S-P needs 10.8 inches of width and 10.8 inches of depth, and Blueair 311i Max needs 12.5 by 12.5. Allow intake clearance as well, and measure the gap in both directions.
- Levoit Core 400S-P
- Depends
- Blueair Blue Pure 311i Max
- Depends
I want to run it from another room
App control is supported by both Levoit Core 400S-P and Blueair 311i Max, so this requirement doesn't separate them. Go on to the room and placement checks.
- Levoit Core 400S-P
- Better fit
- Blueair Blue Pure 311i Max
- Better fit
Ceiling height is ten feet
Modeled at ten feet and five air changes, the room areas shrink to 277 square feet for Levoit Core 400S-P and 340 for Blueair 311i Max. Compared with the eight-foot example, that is 20% less floor area, because the purifier has more air to move.
- Levoit Core 400S-P
- Depends
- Blueair Blue Pure 311i Max
- Depends
In practice
Differences you will notice
Compare room sizes at an equal turnover rate
At five air changes per hour and an eight-foot ceiling, the numbers come to about 347 square feet for Levoit Core 400S-P and 425 for Blueair 311i Max.
How we worked this out
Area = CADR × 60 / (ceiling feet × air changes per hour). The inputs are 231 and 283 CFM, 8 feet and 5 changes, with smoke CADR used at maximum speed. In a real room, air mixing, furniture, open doors and filter loading matter too.
Measure the cabinet first, then buy
Levoit Core 400S-P has a 116.6-square-inch cabinet envelope, compared with 156.3 for Blueair 311i Max. A shallower shape can still need more wall width.
How we worked this out
Width × depth: 10.8 × 10.8 = 116.6 in² and 12.5 × 12.5 = 156.3 in². Cabinet bounding rectangles are what these are, and required air clearance is excluded.
Pollen improves by more than smoke does
Next to the Core 400S-P, the Blueair 311i Max has about 41% more pollen CADR and about 23% more smoke CADR.
How we worked this out
(365 / 259 - 1) × 100 = 40.9%. (283 / 231 - 1) × 100 = 22.5%. The Core 400S figures are taken from its exact US ENERGY STAR record.
Plug in your numbers
Can either purifier keep up with your room?
This checks hard limits only. Personal preferences are left out of the math.
Levoit Core 400S-P
Works with your numbers231 CFM of verified clean-air delivery works out to about 5.8 air changes per hour in this room. Hitting the 5 ACH target takes 200 CFM.
Blueair Blue Pure 311i Max
Works with your numbers283 CFM of verified clean-air delivery works out to about 7.1 air changes per hour in this room. Hitting the 5 ACH target takes 200 CFM.
This uses each model’s pollutant-specific CADR at top speed and a target of five air changes per hour. Quieter settings clean less air. Raw airflow and one-change coverage claims are never swapped in.
Option A
Levoit, LAP-C401S-WUS
Core 400S-P
Small and responsive, this smart purifier moves enough air for a medium room and has one of the better apps in the category.
- Best for
- Bedrooms, offices and living rooms where you want app connectivity and can do without formal HEPA certification
Facts we checked
- The exact LAP-C401S-WUS is certified at 231 CFM for smoke, 240 for dust and 259 for pollen.
- Published sound runs from 24 to 52 dB.
- VeSync brings remote status, schedules, voice control and automatic fan behavior.
Option B
Blueair, 311i Max
Blue Pure 311i Max
Quiet and smart, this cylinder falls between Blueair's compact 511i and larger 211i and delivers serious smoke airflow given its 12.5-inch base.
- Best for
- Medium rooms that call for strong airflow, a washable fabric prefilter and quiet smart operation
Facts we checked
- Certified CADR is 283 CFM for smoke, 314 for dust and 365 for pollen.
- At 4.8 air changes per hour, Blueair lists 439 square feet.
- The cabinet is 12.5 inches wide, with app and automatic modes, and is rated from 23 to 50 dB.
Spec by spec
Where they really differ
| Spec | Levoit Core 400S-P | Blueair Blue Pure 311i Max | In practice |
|---|---|---|---|
| Smoke CADR | 231 CFM | 283 CFM | Better to rely on a smoke-specific rate than on a one-air-change marketing room size. |
| Pollen CADR | 259 CFM | 365 CFM | The model that leads on smoke does not necessarily lead on pollen as well. |
| Cabinet width and depth | 10.8 × 10.8 in | 12.5 × 12.5 in | Check both dimensions against the real gap, and keep the clearance the manual calls for around the intakes. |
| Remote app control | Included | Included | Remote schedules matter if the purifier sits far from where you spend your day. |
| Automatic sensor response | Included | Included | Apps and pollution sensors do separate jobs, and a schedule tells you nothing about air quality. |
| Ionizer or electrostatic stage | none | always-on | If a purely mechanical filter path is what you want, treat this preference as a firm requirement. |
Trade-offs
What each pick costs you
With Levoit Core 400S-P
- Its carbon section targets light household smells and isn't intended for high gas loads.
With Blueair Blue Pure 311i Max
- The carbon layer targets lighter household smells and is not meant for lingering solvent or renovation fumes.
Decision guide
How to decide
For more pollen airflow, the Blueair 311i Max is the choice. The Levoit Core 400S-P fits into a smaller floor space and avoids electrostatic charging.
Pollen gives the wider cabinet a stronger case
Against the Levoit's certified 259, the 311i Max publishes 365 pollen CFM. The smoke advantage is smaller, so go by the particle rating that fits why you're buying.
The cabinet claims a noticeably larger patch of floor
Levoit measures 10.8 inches square and Blueair 12.5. Leave clearance at the intake too, since the cabinet envelope by itself doesn't cover the whole placement requirement.
Both automate, yet their filter paths differ
Both offer app control. What separates them is Levoit's mechanical filtration versus Blueair's HEPASilent electrostatic-assisted filtration, which comes with a washable fabric prefilter.
What this page can’t tell you
- CADR is based on the maximum rated fan speed, and minimum noise and maximum airflow occur at different operating points.
- What these calculations compare is particle-cleaning capacity. Nothing in them promises health outcomes or the removal of a specific gas.
By the numbers
What the data shows
What we found across the air purifiers we compare, plus the checked facts behind each finding.
How many fit
Only 14 of the 70 models checked meet every need here: “Wildfire smoke makes its way inside”, “Floor space is very tight for me”, and “I want it to respond automatically”.
14 models fit, out of 70 checkedShow the facts and the math
How we countedThe count uses each product's current fit ratings for “Wildfire smoke makes its way inside”, “Floor space is very tight for me”, and “I want it to respond automatically”. A need with no documented match is not counted.
| Product | Needs it meets | Facts we checked | Sources |
|---|---|---|---|
| Levoit Core 400S-P |
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| |
| Blueair Blue Pure 311i Max |
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Ready to buy
See today’s price and what owners say
Open either model on Amazon for the current price, customer reviews and delivery options.
Levoit Core 400S-P
A mechanical-only filter path is what you want
See price & reviews on AmazonBlueair Blue Pure 311i Max
Stronger pollen throughput is required
See price & reviews on AmazonEach link opens in a new tab.
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