Coway Airmega 300S

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Overall

#48 in

Air Purifiers

according to Reddit Icon Reddit

Sentiment score76% positive
16
1
4

Top Pros

Top Cons

Last updated: May 27, 2026

Reddit Reviews

Reddit IconBeccan_1
about 1 month ago

I have 3x coway mega (ap1220), coway mega 300s, blue air 7740, philips, airfanta pro. Philips is useless, others are similar and all good. Coways are perhaps my favourites. In paricuoar, Coway 300s is big, which means I can run it on a lower setting, it is quiet but still works. Airfanta is good but looks a bit rough. Blueair is very quiet on a low setting, but too expensive. I would take the largest / with highest capacity you can buy. And check the replacement filter prices before buying, blueair in particular is expensive. I occasionally buy dupes for replacement filters, and last time I could not find any differences between the branded one and the copy on the outside. But obviously, you never know.

Reddit IconHoopsLaureate
8 months ago

I’ve got a Coway 300S in the main living area of my house (kitchen, dining room, living room), and a Coway 1512 in my bedroom. Both have been great! Highly recommend Coway.

Reddit IconMakaks31
6 months ago

This is the coway airmega air purifier which has a coverage area of (I think) 1200 sqft. We keep it in the hallway and it actually gets to green within an hour. The aqi in my area is 222 right now (i haven't seen the aqi monitors here being sprinkled with water or anything but there is constant sprinkling of water on roads to keep the pollutants grounded) but even when the pollution was at peak, this one could purify the air to green in around similar time.

6 months ago

I got coway last year when I started getting breathing problems due to all the pollution. Unless we can somehow control the stubble (parali) burning, the city is doomed!

6 months ago

It's coway airmega 300S Currently out of stock

6 months ago

It's coway airmega 300S It has costed me somewhere around 40k last year

Reddit Iconmindfeck
3 months ago

Yeah my air mega 300s used to be good but can’t even log in anymore. Levoit Everest air is a pleasure.

Reddit IconNumerousAssumption47
3 months ago

Considering the current Coway price tags, I prefer Alen. I have the Coway Airmega 400S and 300S and then recently got the Alen 25i for my small office. Alen hands down has the most pleasant sound. Plus they come with a lifetime warranty if you buy their filters which are reasonably priced.

4 months ago

Hey, you and I are in the same boat. I had a baby boy at 31 weeks, now almost 5 month adjusted, and I went down the air quality rabbit hole hard. I want to do whatever I can to keep him healthy and developing normally. He sleeps with us in our room right now. I have a clean air kits luggable xl pc fan cr box and a IQair Health Pro Plus running on setting 2. Both run 24/7. This gives me a lot of air changes per hour and some gas filtration, while staying below 50 decibels. In the rest of the house, I have more luggable xls, smart air blast, iqair gc and GCX, Coway 400 and 300, and an Alen 25i. I think it’s important to get a standalone air quality monitor like the air gradient one or purple air zen. I run the hvac blower fan 24/7 to circulate air through the house. I also open windows every morning and bring in fresh air to keep CO2 low. I don’t know what your budget is, but you can make your own cr boxes for really cheap and then throw a few nice hepa air purifiers on top. I bought all the expensive units used (iqair, Coway, smart air) and saved a ton of money. Just gave them a good cleaning and new filters. Another important thing is to always run your kitchen hood vent when cooking I’ve been keeping my house between 68-72 degrees Fahrenheit so that he sleeps his best and relative humidity between 45-55%. I have a Midea Cube dehumidifier I run when it’s really humid out and humidity in the house gets above 60%. I also vaccum and mop the floors all the time now. We have an old dog that sheds a lot and the floors get covered in hair if I don’t stay on top of it. I kindof rambled but that’s just been what I have been doing and what purifiers I bought to give you some ideas and things to look into.

5 months ago

I just got an Alen Air 25i for my little office and it’s been a really great unit for the last few weeks. Alen sells bundle “whole house” solutions that might work for you. For me, I put a smart air blast in my living room, a iqair GCX in my kitchen, iqair gc in my dining room/front foyer, Alen 25i in the office, Coway Air Mega 300 and 400s in our spare bedrooms, an iq air health pro plus in the master bedroom, and 4 clean air luggable cr boxes spread out throughout the house. Do I have an addiction to buying air purifiers? Yes. Very weird addiction. But all were bought off Facebook marketplace and were pennies on the dollar compared to new. Just had to give them a good wipe down and put in a new filter.

Reddit IconRumham_1
4 months ago

I have an American Eskimo dog bought this exact purifier expecting a miracle- it will not trap any dog hair so I bought a real air purifier (Coway 300s) for dander and dog smell which has been great. If you have a fluff dog get a robot vacuum like Roborock to vacuum everyday it’s been a life changer

Reddit Iconmanatelier
8 months ago

coway. coway hands down. with two cockatiels i keep one thats supposed to cover 2500 sqft in a tiny bedroom because well…. it requires it, but we want a second one for the rest of the house. they do purifying and have charcoal filters for odors which has been great for cooking etc in the past

Reddit Iconbjyanghang945
9 months ago

I have a CR box with 6 PC fans. The throughput is just not enough to deal with the fire smoke.. ended up turning my actual purifier’s fan speed up. I have the Coway 300. Speed 3(200CFM) worst day 2 of them running.

12 months ago

The machine does a slow ramp up and down when you change speed.. my thought is when you are at speed 2 and you want to change to speed 1, you have to change through 3 and 4… and 3 and 4 are fast and noisy(I use 3 normally at day time). A “delayed” changed can be helpful.

12 months ago

Oooooooh interesting… I really thought 300 and 400 are the same except bigger.. I only have 2 of the 300

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