Coway - Airmega 400S

I feel like having an air purifier that's bigger than the coverage of my space gives me a lot of peace of mind when it comes to air quality. Like i know the appliance is powerful enough to take on more my current square footage so it feels like my air is extra clean. I have the 400s and it connects to the app so i can control the air purifier from anywhere in the house, it's pretty cool.

I like Coway. Silent, dealt with wildfire smoke perfectly.

I recommend Coway. Just make sure you are paying attention to the sq ft coverage.

Coway 400S. Best air filter we have ever owned. We have 4 of them in a 4000+ square for house where we foster cats (10+ at any time,) and the amount of fur, dust, and general particles it filters out is amazing. Friends who are severely allergic to cats come over with zero issues with these filters running.

[link to them on Amazon](https://a.co/d/iQKjYKh) Unfortunately, we got ours on Amazon - we’ve been trying to avoid buying from Amazon after Bezos decided to censor his newspaper (New York Post,) but regardless, these machines are built extremely well. I do not know the specifics on warranty, but we have had two of them for more than six years and two more for more than four years and zero issues with any of them - we just change the filters about once a year and vacuum the filters every other month of so - they pick up a mind blowing about of debris from the air and floor of your house - I’ll find large pieces of cat toys (feathers) that (after deduction and piecing things together,) tracked that the debris travelled over several rooms and through doorways over time to get into the outer filter where the big stuff sits to be vacuumed out. 100% Will buy another if something happened to one of ours, which I am assuming will be an accidental incident and not breakdown mechanically - as I said, they are very well built. Edit - looks like a 5 year warranty, but as you will see if you get one, well made and not simple in the way that makes it really well built - fewer, and higher quality parts.

I’ve got two cats and a golden retriever, so air purifiers became non-negotiable for me. The one that’s made the biggest difference is the Coway Airmega 400S.

I’ve been drowning in dog and cat hair until I got a Coway Airmega 400S. Its true HEPA filter grabs fur and dander, and the activated carbon core neutralizes pet odors.

Ugh. I just bought a 400S a week ago. Should I return and get the 400 instead? I do like that I can tell google to turn it on or off. But it’s almost a 200$ convenience.

They aren’t going to price match 400 price for 400S. The price of 400S hasn’t changed.

FYI: the fan on the microwave can still help, there is usually a carbon filter that will need periodic replacement. I just placed a Coway 400s next to my 3D printer. The carbon filter definitely helps when I am printing ABS filament. I also have some older 6 fan Shark towers that are now discontinued. They don’t have carbon filters, but still helped a great deal when cooking. For my Cuisinart electric grill, I have a smaller Shark cylinder next to it. When I grill salmon it quickly goes into low air quality (red) mode. The other units on the first floor (two Shark 6 fan towers) also go red and max filtration. Bottom line is that I find air filtration works well, but it does take some time to exchange enough air to reduce the cooking odors. Maybe a half hour with 2 large and one small unit running in auto mode. I think that two well placed Coways would probably exchange enough air to eliminate the odors fairly quickly. Put a smaller unit in the kitchen on the countertop near the stove for even more air exchange.

Yeah Coway Airmega works so well. I have S400 and it's been fantastic.

I love our coways too.

I have 2 Coway Airmega 400s. They are absolute beasts for high CADR hepa, and do include a solid size carbon filter option that you can add. They really work for pets.

I think it's a good choice. Whatever slight adhesive smell may be there initially will be gone within a day

This is the answer. We have 2 and my battered lungs instantly told me they were a good buy. Quiet too except when there is cooking fumes in the air.

I use an IqAir GC, Coway Airmega 400s, and Coway Ap1513. I have invested in these over the years and bought them from wholesale or second hand. They are all heavy-duty purifiers, but anything with a hepa filter will do. Make sure if you are on multiple floors... air purifier on each floor. Make sure it's double the sq.ft of the area you want to filter. If it's not enough.. double up.

I highly recommend coway. I think it makes a difference since filters are covered in dust

Mine is a few rooms away from the kitchen and it detects dirty air and kicks into high speed when I cook.

I bought a used Coway Airmega 400S for $200, that came with a brand new set of OEM filters, the best purchase ever, and large enough to quickly cover 700 sq ft space in about 15 min for a complete air exchange. CADR (Clean Air Delivery Rate): 328 (Smoke), 328 (Dust), 400 (Pollen) Really love how quiet it is and the air monitoring report and air quality sensor. I've had a home improvement project going and as soon as dust started flying the air filter on auto setting cranked all the way to the max to counter. The over 350CFM air flow pushes a massive amount of air on max and surprisingly it's not even as loud as my old Holmes HAP756NU at medium setting.

I agree with Coway. We have one near our kitchen that filters out cooking smells quite well. Somewhat proof that it works!

I've had mine for about a year now (the 400S model) and you can genuinely feel the difference. I used to wake up stuffy every day because of city air and bad allergies, but after running the Airmega overnight in my bedroom, it pretty much solved that issue for me. 

I rely on the Coway Airmega 400S for my dogs because it traps fur and helps with pet smells without getting too noisy.

Another vote for Coway. I have pretty bad dust and pollen allergies and am lucky enough to be able to sleep in a separate room that no one else goes in. I think I just dusted for the first time in a year, the rag was only a little dirty. They are pretty sensitive to any sort of oil-frying/sauteeing in a pan, making fried rice sends it scrambling (we have a second machine near the living area.) I prefer to crack a door for a few minutes to replace the air rather than wait for the machine to filter it.

The one that made the biggest difference for me was the Coway Airmega 400S. It’s quiet enough for my bedroom and still pulls fur and dander out of the air in bigger rooms.

It wasn't worth the convenience for me to get the S version. If you purchased it a week ago, it may be worth reaching out to see if they will honor the sale price for you. I'm sure it wouldn't be worth their hassle take a return in and re-ship another.

I have two of the Coway ones (the $200 ones, which seem to go on sale fairly regularly) and it helps my seasonal allergies quite a bit.

My daughter has asthma so we run air purifiers in several rooms in the house, it seems to help a lot. We have Coways and Levoits but if I was starting from nothing I’d run all levoiits.

The activated carbon filters on your Coway Airmega 400S should be indeed lowering your indoor VOC concentrations, along with the particulate removal from the HEPA filter. The activated carbon filters need to be replaced periodically to continue absorbing, but every few months should be fine. I wonder whether your Airthings View Plus sensor for VOC (metal oxide sensor) is not accurately measuring low levels of concentration. It could be reporting a constant 250 ppb, but the actual concentration might be much lower. Have you tried taking it outdoors temporarily, or measuring the air flow directly from your air filter effluent? My suggestion having a PhD in air quality: 1. Keep your air purifiers on 24/7 2. Replace activated carbon filters as recommended by Coway 3. Minimize VOC sources in your home (electric not gas stove/oven, buy wood not particle board furniture, don't burn candles, stay away from personal fragrances, etc.).

I’ve recently purchased Coway Airmega 400S as I the air was getting polluted way too frequently due to wildfires in summer. While it was able to reduce PM2.5 drastically, it made no difference to VOCs which my Airthings View Plus consistently detects around 250 ppb. So I purchased Austin Air Healthmate+ HM450 believing the higher carbon content in its filters will be more effective but after I tested it today it is also not making much of a difference. Do other people have similar problem with VOCs and is there a purifier which is better at this? After Austin Air in my mind IQ Air is the one to try but I don’t know if I want to spend so much on the purifier. Am I expecting too much from the purifiers? I will try if at some point VOCs are higher (sometimes it’s >500 ppb) and in that case if the purifiers make a difference. But it’s been frustrating to research and buy multiple purifiers and see them making no difference to VOCs. Any help will be appreciated. Edit: I live in Toronto and my goal is to keep the air in kitchen/dining clean which is around 400 sq ft. However there are no doors separating these areas with the rest of the floor. The entire floor is around 1700 sq ft and the whole house is 3000 sq ft Edit 2: I am also planning to install an ERV. So I am wondering if that’s going to make a significant difference and whether I give up trying to fix the VOC levels using purifiers. If anyone has experience with ERVs that will also be much appreciated

There are walls separating different sections on the main floor but no doors. I see Austin Air is rated high by many redditors here but I don’t see it making any impact on VOCs as I measure them on my airthings view plus monitor.

I am torn between the choices of - whether I keep the Coway 400s which is theoretically inferior but is cheaper, better looking and has smart features or I keep the ugly looking but on paper better Austin Air and just trust the fact it’s doing some thing to VOCs even when I can’t prove it with the air quality monitor

Ive had a coway since before covid and it’s excellent.

For most applications, Coway has the best build quality of the brands here. I should also mention Blueair, [which offers a 5 years warranty with registration for certain models](https://www.blueair.com/us/warranty.html). All Blueair purifiers utilize an always-on ionizer to electrostatically charge the filtration media. While I'm not quite certain on comparisons, Smart Air's Blast and Blast Mini air purifiers might be similar in quality or greater to Coway's higher-end Airmega purifiers. But those two Smart Air models are expensive. For the [Coway Airmega 300/300S, 400/400S, Icon/IconS\*, and ProX models, the warranty period is 5 years](https://cowaymega.com/pages/warranty-registration). \*We don't recommend the Icon or IconS models as they're poor value for money.

...different websites display different levels of expertise or due diligence? There are traditional and online media websites "reviewing" purifiers whose methodologies, criteria, or testing will vary. Many product review articles authors are journalists, not HVAC or air quality engineers. And the underlying goal of some websites may be to drive viewers towards referral or affiliate URLs to make money. You have to compare apples to apples. RTings.com has tested only 2 Coway models and 2 Winix models. There are no Smart Air, IQAir, Alen, or Medify Air units. I'm looking forward to RTings.com testing more purifier models. But right now, the test selection isn't impressive... there are a lot of Dyson purifiers. As stated on one of your other posts, we generally like Coway for the build quality, performance, and quiet operation. The ProX, 400S, 400, 300S, 300, IconS\*, and Icon\* come with a 5 years warranty. All other Airmega models have a 3 years warranty. Link: [https://cowaymega.com/pages/warranty-registration](https://cowaymega.com/pages/warranty-registration) \*We do not recommend the Icon / IconS, as they have poor CADRs for the money. The Levoit EverestAir is the best purifier Levoit makes with lots of extra features. Some of the CADRs are a bit low (373 CFM for Dust and 354 CFM for Smoke). Top sound level according to HouseFresh is 57.8 dB; note this isn't an A-weighted decibel rating. Warranty period is 2 years. Don't know how the EverestAir's build quality compares to Coway's higher end offerings.

\+1 - I have coway's and have been pleased with their performance thus far. I also vacuum around the dog pen to collect hair and I haven't had much smell other when they come in from being outside.

selling my conway 400s if anyone in ny tristate area on fb market .. upgraded to something stronger to put in my cigar room I'm currently building

would be worth cross-referencing with this thread: https://www.reddit.com/r/BuyItForLife/s/iG0y1wJ4JO there are also a couple other almost identical asks if you search reddit. different communities might highlight different strengths. i’ve been real happy with my Coway Airmega 400. the S model is “smart.”

Coway and BlueAir are great. Make sure it says "True HEPA," unless you build a corsi-rosenthal box Levoit ones aren't always true hepa.