The catch
Coway Airmega 400
You won't get a Wi-Fi app, scheduling or a detailed air-quality history.
Side by side
Coway Airmega 400 vs Blueair 211i Max: A lighter cabinet with more smoke airflow comes from Blueair
Quick verdict
The Blueair 211i Max is the pick for stronger smoke airflow in a lighter cabinet. If you prefer mechanical-only operation without app setup, the Airmega 400 fits.
Before you buy
Why, and what it costs you
Compare room sizes at an equal turnover rate
Coway Airmega 400 works out to about 492 square feet and Blueair 211i Max to 653, at five air changes per hour and an eight-foot ceiling.
Where this comes from
Area = CADR × 60 / (ceiling feet × air changes per hour). Inputs are 328 and 435 CFM, 8 feet and 5 changes. Smoke CADR is used at maximum speed. Real conditions depend on air mixing, furniture, open doors and filter loading.
The catch
Blueair Blue Pure 211i Max
You can't turn off the HEPASilent ionization stage, which stays active all the time.
Coway Airmega 400
- Why pick it
- A mechanical-only air path is your goal
- Controls on the unit appeal
- The catch
- You won't get a Wi-Fi app, scheduling or a detailed air-quality history.
The Airmega 400 photo shows Graphite, while the Amazon listing selects White. Its purchase link is paused while the exact finish is verified.
Blueair Blue Pure 211i Max
- Why pick it
- More smoke airflow is needed for a larger room
- The purifier changes rooms now and then
- The catch
- You can't turn off the HEPASilent ionization stage, which stays active all the time.
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What this page compares
Stronger smoke airflow in a lighter cabinet points to the Blueair 211i Max. The Airmega 400 fits a mechanical-only preference and needs no app setup.
The gap is wider for smoke than for pollen
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, Coway Airmega 400 calculates to a limit of 492 square feet and Blueair 211i Max to 653. If you want to run below maximum speed, leave margin.
- Coway Airmega 400
- Depends
- Blueair Blue Pure 211i Max
- Better fit
The cabinet needs to fit next to furniture
Coway Airmega 400 needs 14.8 inches of width and 14.8 inches of depth, and Blueair 211i Max needs 14.4 by 14.4. Intake clearance comes extra, so measure the gap in both directions.
- Coway Airmega 400
- Depends
- Blueair Blue Pure 211i Max
- Depends
I want to run it from another room
App control comes with the Blueair 211i Max. Coway Airmega 400 relies on local controls, which fit a fixed routine but cannot satisfy a remote-control requirement.
- Coway Airmega 400
- Not suitable
- Blueair Blue Pure 211i Max
- Better fit
Ceiling height is ten feet
Raise the ceiling to ten feet with five air changes and the modeled room areas fall to 394 square feet for Coway Airmega 400 and 522 for Blueair 211i Max. That is 20% less floor area than the eight-foot example, since the purifier has more air to move.
- Coway Airmega 400
- Depends
- Blueair Blue Pure 211i Max
- Depends
In practice
Differences you will notice
Compare room sizes at an equal turnover rate
Coway Airmega 400 works out to about 492 square feet and Blueair 211i Max to 653, at five air changes per hour and an eight-foot ceiling.
How we worked this out
Area = CADR × 60 / (ceiling feet × air changes per hour). Inputs are 328 and 435 CFM, 8 feet and 5 changes. Smoke CADR is used at maximum speed. Real conditions depend on air mixing, furniture, open doors and filter loading.
Measure the cabinet first, then buy
Coway Airmega 400 has a 219-square-inch cabinet envelope, compared with 207.4 for Blueair 211i Max. A shallower shape can still call for more wall width.
How we worked this out
Width × depth: 14.8 × 14.8 = 219 in² and 14.4 × 14.4 = 207.4 in². These are cabinet bounding rectangles without the required air clearance.
More smoke airflow and no heavier to carry
The 211i Max has about 33% more smoke CADR than the Airmega 400 and weighs about 34% less.
How we worked this out
(435 / 328 - 1) × 100 = 32.6%. (24.7 - 16.2) / 24.7 × 100 = 34.4%. Neither carry comfort nor noise was tested.
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.
Coway Airmega 400
Works with your numbers328 CFM of verified clean-air delivery works out to about 8.2 air changes per hour in this room. Hitting the 5 ACH target takes 200 CFM.
Blueair Blue Pure 211i Max
Works with your numbers435 CFM of verified clean-air delivery works out to about 10.9 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
Coway, AP-2015F
Airmega 400
Wide and high in airflow, this purifier has dual filters, two washable prefilters and straightforward automatic controls, with no app involved.
- Best for
- Large rooms with smoke or allergy problems, if you value a mechanical HEPA system over connected features
Facts we checked
- Coway's rating for the platform is up to 3,120 square feet at one air change per hour.
- Published CADR is 328 CFM for smoke, 328 for dust and 400 for pollen.
- Two combined Max2 HEPA-and-carbon filters sit behind two washable prefilters.
The Airmega 400 photo shows Graphite, while the Amazon listing selects White. Its purchase link is paused while the exact finish is verified.
Option B
Blueair, 211i Max
Blue Pure 211i Max
This large-room cylinder runs quietly and efficiently, with a high CADR, a washable fabric prefilter and handy app automation.
- Best for
- Open living areas, pets and smoke, when quiet high airflow outranks deep gas filtration
Facts we checked
- Blueair lists a room size of 674 square feet at 4.8 air changes per hour.
- Published CADR is 435 CFM for smoke, 452 for dust and 450 for pollen.
- The purifier weighs 16.2 pounds, has app, auto and night modes, and is rated at 23 to 53 dB.
Spec by spec
Where they really differ
| Spec | Coway Airmega 400 | Blueair Blue Pure 211i Max | In practice |
|---|---|---|---|
| Smoke CADR | 328 CFM | 435 CFM | Better to rely on a smoke-specific rate than on a one-air-change marketing room size. |
| Pollen CADR | 400 CFM | 450 CFM | The model that leads on smoke does not necessarily lead on pollen as well. |
| Cabinet width and depth | 14.8 × 14.8 in | 14.4 × 14.4 in | Check both dimensions against the real gap, and keep the clearance the manual calls for around the intakes. |
| Remote app control | No app | 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. |
| Published weight | 24.7 lb | 16.2 lb | A heavy cabinet bothers you less if it stays put than if it must go upstairs every day. |
| Rated power | 66 W | 46 W | Rated input is a comparison of upper limits. Actual consumption shifts with Auto mode and lower fan settings. |
Trade-offs
What each pick costs you
With Coway Airmega 400
- The wide body takes up a lot of floor space and needs room to breathe on both intake sides.
With Blueair Blue Pure 211i Max
- To keep airflow up, the fabric prefilter has to be vacuumed or washed from time to time.
Decision guide
How to decide
Go with the Blueair 211i Max for stronger smoke airflow and a lighter cabinet, or with the Airmega 400 for a mechanical-only preference and no app setup.
The gap is wider for smoke than for pollen
Blueair's lead is 107 CFM on smoke CADR and 50 on pollen. The extra smoke headroom counts most when the room is large enough to push the Coway toward maximum speed.
The model with more airflow weighs less
Coway weighs 24.7 pounds and the 211i Max 16.2. That 8.5-pound reduction can matter when the purifier alternates between a downstairs living space and a bedroom.
Pick the air-cleaning path on purpose
Mechanical filtration is what Coway uses, and Blueair relies on electrostatic-assisted HEPASilent filtration. Both have automatic modes, so a preference for an app need not settle the purchase on its own.
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 checkedThe gap in numbers
Blueair Blue Pure 211i Max lists 435 CFM for listed smoke CADR, 33% more than the 328 CFM on Coway Airmega 400.
- Coway Airmega 400
- 328 CFM
- Blueair Blue Pure 211i Max
- 435 CFM
- Models with this figure
- 20 of 70
Show 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.
How we calculatedOnly figures stated as smoke CADR go into this median. General maximum-airflow numbers are left out. For context, 20 of 70 models publish comparable figures.
| Product | Needs it meets | Facts we checked | Sources |
|---|---|---|---|
| Coway Airmega 400 |
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| Blueair Blue Pure 211i 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.
Coway Airmega 400
A mechanical-only air path is your goal
The Airmega 400 photo shows Graphite, while the Amazon listing selects White. Its purchase link is paused while the exact finish is verified.
Blueair Blue Pure 211i Max
More smoke airflow is needed for a larger room
See price & reviews on AmazonEach link opens in a new tab.
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