The catch
Coway Airmega 250
Its price is close to some connected competitors, yet it offers no app or scheduling.
Side by side
Coway Airmega 250 vs Coway Airmega 400: Beside furniture 250 takes less depth, while 400 adds airflow
Quick verdict
For a larger living room, go with the Airmega 400. The Airmega 250 is the better fit next to furniture when there is little front-to-back depth.
Before you buy
Why, and what it costs you
Compare room sizes at an equal turnover rate
Working at five air changes per hour with an eight-foot ceiling, the numbers come to about 374 square feet for Coway Airmega 250 and 492 for Coway Airmega 400.
Where this comes from
Area = CADR × 60 / (ceiling feet × air changes per hour). The inputs are 249 and 328 CFM, 8 feet and 5 changes. Smoke CADR is taken at maximum speed. Real conditions are affected by air mixing, furniture, open doors and filter loading.
The catch
Coway Airmega 400
You won't get a Wi-Fi app, scheduling or a detailed air-quality history.
Coway Airmega 250
- Why pick it
- It has to stand close to a wall
- You can limit the room to about 350 square feet
- The catch
- Its price is close to some connected competitors, yet it offers no app or scheduling.
Coway Airmega 400
- Why pick it
- More airflow is needed for a larger open room
- There's space for a square cabinet
- 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.
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What this page compares
The Airmega 400 is the pick for a larger living room. Where front-to-back depth is tight beside furniture, the Airmega 250 fits better.
The shallow model leaves the walkway free
Which one fits
Pick the situations that sound like you
The room is big enough to call for extra airflow
With the same five-change target and eight-foot ceiling, the calculated limits come to 374 square feet for Coway Airmega 250 and 492 for Coway Airmega 400. Leave some margin if you plan to run below maximum speed.
- Coway Airmega 250
- Depends
- Coway Airmega 400
- Better fit
The cabinet needs to fit next to furniture
Coway Airmega 250 needs 18.5 inches of width and 8.3 inches of depth, and Coway Airmega 400 needs 14.8 by 14.8. Intake clearance comes on top of that, so measure the gap in both directions.
- Coway Airmega 250
- Depends
- Coway Airmega 400
- Depends
I want to run it from another room
Coway Airmega 250 and Coway Airmega 400 both lack app control. If remote schedules are essential, choose a connected alternative.
- Coway Airmega 250
- Not suitable
- Coway Airmega 400
- Not suitable
Ceiling height is ten feet
Modeled at ten feet and five air changes, the room areas drop to 299 square feet for Coway Airmega 250 and 394 for Coway Airmega 400. That is 20% less floor area than in the eight-foot example, since the purifier has more air to move.
- Coway Airmega 250
- Depends
- Coway Airmega 400
- Depends
In practice
Differences you will notice
Compare room sizes at an equal turnover rate
Working at five air changes per hour with an eight-foot ceiling, the numbers come to about 374 square feet for Coway Airmega 250 and 492 for Coway Airmega 400.
How we worked this out
Area = CADR × 60 / (ceiling feet × air changes per hour). The inputs are 249 and 328 CFM, 8 feet and 5 changes. Smoke CADR is taken at maximum speed. Real conditions are affected by air mixing, furniture, open doors and filter loading.
Measure the cabinet first, then buy
Coway Airmega 250 has a 153.6-square-inch cabinet envelope, compared with 219 for Coway Airmega 400. Even a shallower shape may call for more wall width.
How we worked this out
Width × depth: 18.5 × 8.3 = 153.6 in² and 14.8 × 14.8 = 219 in². Both figures are the bounding rectangle of the cabinet and leave out the air clearance it needs.
Two filters against one
Each change on the Airmega 400 takes two Max2 filters, but the 250 takes one. That makes for a different maintenance purchase, even when each listing shows a single filter price.
How we worked this out
For the 400, Coway lists a Max2 filter set, and for the 250 a single Max2 filter. Compare complete replacement sets and not the price of each cartridge.
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 250
Works with your numbers249 CFM of verified clean-air delivery works out to about 6.2 air changes per hour in this room. Hitting the 5 ACH target takes 200 CFM.
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.
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-1720F
Airmega 250
Compared with the 250S, the 250 without Wi-Fi gives up the app but retains the broad front intake, washable prefilter and automatic modes.
- Best for
- A medium living room with pets, if automatic controls on the unit and easy prefilter care are all you need
Facts we checked
- Coway's published CADR values are 249 CFM for smoke, 261 for dust and 230 for pollen.
- Its rating of 465 square feet is stated at four air changes per hour.
- A washable prefilter sits in front of the Max2 filter, which has a stated life of about one year.
Option B
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.
Spec by spec
Where they really differ
| Spec | Coway Airmega 250 | Coway Airmega 400 | In practice |
|---|---|---|---|
| Smoke CADR | 249 CFM | 328 CFM | Better to rely on a smoke-specific rate than on a one-air-change marketing room size. |
| Pollen CADR | 230 CFM | 400 CFM | The model that leads on smoke does not necessarily lead on pollen as well. |
| Cabinet width and depth | 18.5 × 8.3 in | 14.8 × 14.8 in | Check both dimensions against the real gap, and keep the clearance the manual calls for around the intakes. |
| Remote app control | No app | No app | 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 | none | If a purely mechanical filter path is what you want, treat this preference as a firm requirement. |
| Published weight | 20.5 lb | 24.7 lb | A heavy cabinet bothers you less if it stays put than if it must go upstairs every day. |
| Rated power | 64 W | 66 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 250
- A cylinder takes less wall width than the broad 18.5-inch face.
With Coway Airmega 400
- The wide body takes up a lot of floor space and needs room to breathe on both intake sides.
Decision guide
How to decide
Pick the Airmega 400 if the living room is larger. Beside furniture with tight front-to-back depth, the Airmega 250 sits better.
The shallow model leaves the walkway free
The 250 is shallower by 6.5 inches. In return, the 400 adds 79 smoke CFM, enough for about 119 extra square feet at five air changes and an eight-foot ceiling.
A higher ceiling may change your pick
Once the ceiling is ten feet high, the same five-change target drops to about 299 square feet for the 250 and 394 for the 400. Measure your ceiling before relying on the big coverage number printed on a box.
Price the whole filter set and look past a single cartridge
Air enters the 400 from two sides, and it uses a pair of Max2 filters. The 250 takes one Max2 filter. Any replacement quote has to cover the entire working set.
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 |
|---|---|---|---|
| Coway Airmega 250 |
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| Coway Airmega 400 |
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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 250
It has to stand close to a wall
See price & reviews on AmazonCoway Airmega 400
More airflow is needed for a larger open room
The Airmega 400 photo shows Graphite, while the Amazon listing selects White. Its purchase link is paused while the exact finish is verified.
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