Coway
Airmega 450
Based on 20 Reddit mentions
$499.00
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Most discussed features
Sentiment summary across the product areas Reddit users mention most.
Reddit mentions
Original Reddit posts and comments behind this analysis.
Any reason not to go totally overkill and get an excessively strong air purifier?
Most brands overstate coverage ratings. If you see a large figure (e.g., 1,500 - 3,000+ sq. ft.), this is likely at 1 to 2 Air Changes per Hour (ACH) which is too low. In any case, Clean Air Delivery Rates (CADRs) are the better metric. The Coway Airmega 400 has a top Smoke CADR of 328 CFM. Based on
...sissasassafrastic in r/AirPurifiers
May 8, 2026 10:23 PM
4
Large bedroom purifier recommendations
So you prefaced 1,400 square feet as "Room Volume". I assume this is still square feet and not 1,400 cubic feet, the latter actually being volume. Purifiers aren't good at removing visible dust particles as they're large and heavy. See the sticky post at the top of the subreddit and our FAQs wiki pa
...sissasassafrastic in r/AirPurifiers
June 20, 2026 10:45 PM
3
Severe allergies, 1230 sq condo. Need some help
So unfortunately cigarette or marijuana smoke isn't just particulates, but also gases/vapors/odors/VOCs. You need many pounds of activated carbon and/or other sorbent media for gases/vapors/odors/VOCs. Heavyweight sorbent media purifiers are very loud, very expensive (~$600 and up), and clean the ai
...sissasassafrastic in r/AirPurifiers
July 8, 2026 8:51 PM
3
Please help me choose which one!!
I wouldn't focus on coverage ratings, as brands like to inflate them. With a big number like 1,700 sq. ft., this is probably at 1-2 Air Changes per Hour (ACH) which is too low. Generally you want a minimum of 4.8-5 ACH. Even so, the more important metrics are Clean Air Delivery Rates (CADRs). And ye
...sissasassafrastic in r/AirPurifiers
September 28, 2025 3:10 PM
5
Best AirPurifier unlimited budget
An IQ air HealthPro 250 XE is considerably better for the same price, but of course, it's quite ugly; they've had the same design for 30 years. Another option would be a Coway Airmega 450, but I personally don't like the treated green filters they use.
Walla-Expert in r/AirPurifiers
April 6, 2026 9:32 AM
3
Air filtering during a wildfire
I have a coway airmega 450 and I keep a wildfire filter stocked in the closet. It was $100 for the filter, but I don’t use it everyday. It’s only in case we have a wildfire. It’s worth it because when we do it keeps my whole house from smelling awful.
thiquegoth in r/AirPurifiers
June 24, 2026 4:57 PM
2
Coway Sale - Need to pick one
Going by the AHAM 2/3 rule, your 15' x 15' x 10' bedroom needs minimum Clean Air Delivery Rates (CADRs) of 188 CFM. The Coway Airmega 250S can achieve that, although I don't know if you have allergies, high pollution levels, or other circumstances that need increased CADRs. The Coway Airmega 450 doe
...sissasassafrastic in r/AirPurifiers
September 27, 2025 11:56 PM
3
Are Airmega cylinders worse that boxes? I cannot find definitive answers to this.
Honestly, I'm not sure if you'll really notice a difference in terms of performance and getting your air clean. My understanding is that the difference comes from potential longevity of the filters. Having a dedicated removable pre-filter and regular cleaning will prolong the life of the HEPA filter
...hartofalyon in r/AirPurifiers
November 24, 2025 7:45 AM
3
Please help me choose which one!!
I see, thanks. FYI: unfortunately purifiers aren't good at reducing visible dust and pet hair. Both are large and heavy compared to "invisible" pollutants like PM10, PM2.5, and PM0.1. See the sticky post at the top of this subreddit and entries from our FAQs wiki page: I need an air purifier for dus
...sissasassafrastic in r/AirPurifiers
September 28, 2025 4:13 PM
2
Allergic to dust/dust mites and dander: are these good options?
With dust mite allergens, you can try reducing relative humidity (RH) below 50% for a prolonged period. (Another study recommended RH of 45% or lower if I recall correctly.) This should kill them off. For the bedroom: of the two, I would tend to choose the Coway Airmega 350. You'll definitely need t
...sissasassafrastic in r/AirPurifiers
October 4, 2025 6:58 PM
2