The catch
Coway Airmega 300
Since the two Max2 filters are replaced together, compare what the full set costs.
Side by side
Coway Airmega 300 vs Coway Airmega 250: 250 takes less depth, 300 gives more pollen airflow
Quick verdict
The Airmega 300 is the pick for more pollen airflow. Beside furniture in a narrow room, the Airmega 250 works better because it is much shallower.
Before you buy
Why, and what it costs you
Compare room sizes at an equal turnover rate
With five air changes per hour and an eight-foot ceiling, Coway Airmega 300 calculates to about 428 square feet and Coway Airmega 250 to 374.
Where this comes from
Area = CADR × 60 / (ceiling feet × air changes per hour). The inputs are 285 and 249 CFM, 8 feet and 5 changes, with smoke CADR at maximum speed. Air mixing, furniture, open doors and filter loading all affect real conditions.
The catch
Coway Airmega 250
Its price is close to some connected competitors, yet it offers no app or scheduling.
Coway Airmega 300
- Why pick it
- Pollen airflow ranks high
- Your room can take a square cabinet
- The catch
- Since the two Max2 filters are replaced together, compare what the full set costs.
Coway Airmega 250
- Why pick it
- A shallow front-to-back shape is needed
- Buying a single replacement filter is simpler
- The catch
- Its price is close to some connected competitors, yet it offers no app or scheduling.
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What this page compares
More pollen airflow points to the Airmega 300. In a narrow room, the much shallower Airmega 250 works better beside furniture.
Pollen is the strongest argument for the 300
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 300 has a calculated limit of 428 square feet and Coway Airmega 250 has 374. Build in some margin if you want to run below maximum speed.
- Coway Airmega 300
- Better fit
- Coway Airmega 250
- Depends
The cabinet needs to fit next to furniture
Coway Airmega 300 needs 13.6 inches of width and 13.6 inches of depth, and Coway Airmega 250 needs 18.5 by 8.3. Intake clearance is extra, so measure the gap both ways.
- Coway Airmega 300
- Depends
- Coway Airmega 250
- Depends
I want to run it from another room
Coway Airmega 300 and Coway Airmega 250 both lack app control. For essential remote schedules, pick a connected alternative.
- Coway Airmega 300
- Not suitable
- Coway Airmega 250
- Not suitable
Ceiling height is ten feet
Modeled at ten feet and five air changes, the room areas fall to 342 square feet for Coway Airmega 300 and 299 for Coway Airmega 250. Compared with the eight-foot example, that is 20% less floor area, because the purifier has more air to move.
- Coway Airmega 300
- Depends
- Coway Airmega 250
- Depends
In practice
Differences you will notice
Compare room sizes at an equal turnover rate
With five air changes per hour and an eight-foot ceiling, Coway Airmega 300 calculates to about 428 square feet and Coway Airmega 250 to 374.
How we worked this out
Area = CADR × 60 / (ceiling feet × air changes per hour). The inputs are 285 and 249 CFM, 8 feet and 5 changes, with smoke CADR at maximum speed. Air mixing, furniture, open doors and filter loading all affect real conditions.
Measure the cabinet first, then buy
Coway Airmega 300 has a 185-square-inch cabinet envelope, compared with 153.6 for Coway Airmega 250. A shallower shape can still call for more wall width.
How we worked this out
Width × depth: 13.6 × 13.6 = 185 in² and 18.5 × 8.3 = 153.6 in². These are cabinet bounding rectangles and exclude required air clearance.
The rise in pollen is much bigger than the rise in smoke
Over the 250, the Airmega 300 gains about 47% in pollen CADR and about 14% in smoke CADR.
How we worked this out
(339 / 230 - 1) × 100 = 47.4%. (285 / 249 - 1) × 100 = 14.5%. Every value comes from the official US model specification.
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 300
Works with your numbers285 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.
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.
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-1515H
Airmega 300
This two-sided living-room purifier has washable prefilters and automatic fan control, and it needs no app setup.
- Best for
- A shared room where controls on the unit and washable intake screens will do
Facts we checked
- CADR is 285 CFM for smoke, 306 for dust and 339 for pollen.
- The cabinet is 13.6 by 13.6 by 21.2 inches and weighs 21.4 lb.
- Power is rated at 57 watts. Auto and Eco modes run without Wi-Fi.
Option B
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.
Spec by spec
Where they really differ
| Spec | Coway Airmega 300 | Coway Airmega 250 | In practice |
|---|---|---|---|
| Smoke CADR | 285 CFM | 249 CFM | Better to rely on a smoke-specific rate than on a one-air-change marketing room size. |
| Pollen CADR | 339 CFM | 230 CFM | The model that leads on smoke does not necessarily lead on pollen as well. |
| Cabinet width and depth | 13.6 × 13.6 in | 18.5 × 8.3 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 | 21.4 lb | 20.5 lb | A heavy cabinet bothers you less if it stays put than if it must go upstairs every day. |
| Rated power | 57 W | 64 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 300
- The 2,512-square-foot headline refers to one air change per hour. Our smoke sizing example at five changes comes to about 428 square feet.
With Coway Airmega 250
- A cylinder takes less wall width than the broad 18.5-inch face.
Decision guide
How to decide
Pick the Airmega 300 for more pollen airflow. The Airmega 250 is much shallower, which suits a narrow room with furniture alongside.
Pollen is the strongest argument for the 300
Pollen CFM is 339 for the 300 against 230 for the 250. Smoke only rises from 249 to 285, so why you're buying matters more than the higher model number.
The 250 takes more wall width but uses less walkway
The 250 measures 18.5 by 8.3 inches, so it is wide and shallow, while the 300 is 13.6 inches square. Measure both dimensions before deciding which looks compact.
Upkeep means buying something different
A paired Max2 set goes in the 300, and the 250 takes a single Max2 filter. Compare the cost of a full replacement set and how easy it is to reach, and don't assume the same filter fits both.
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 300 |
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| Coway Airmega 250 |
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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 300
Pollen airflow ranks high
See price & reviews on AmazonCoway Airmega 250
A shallow front-to-back shape is needed
See price & reviews on AmazonEach link opens in a new tab.
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