While I’ve always cared about health and wellness, I never thought much about air pollution until I encountered some staggering figures. According to the World Health Organization, air pollution is so widespread that 99% of the world’s population breathes unhealthy air, laden with particulates from burning fossil fuels. Now, air pollution is something I think about every week. And when it comes to air quality in your own home, one of the only things you can do is invest in an air purifier, which is what I did two years ago when I bought the Coway Airmega Mighty.
If you want fresh, HEPA-filtered air, try the Coway Airmega Mighty Air Purifier. It’s not cheap to buy or run, but thanks to its reliability and simple design, it’s a true “set it and forget it” appliance that’ll last years.
$240 $180 at Coway $230 $210 at Amazon $216 at The Home Depot
What I liked about it
Its top-notch, reliable performance
You could call the Coway Mighty the Toyota of air purifiers because I’ve been running this thing nonstop for two years, and it hasn’t stuttered or failed once. That’s impressive for any machine — let alone one that’s on 24/7.
While I don’t have precise air quality monitors to test the Mighty’s performance, I know it’s working. When I light a candle or there’s smoke from the kitchen, the machine’s fan comes alive, and the smoke dissipates in less than a minute.
The Coway Airmega Mighty's air quality monitor reacting to smoke.
It’s also a top performer on paper. (Warning: Data incoming.) On the highest setting, its Clean Air Delivery Rate (CADR), which measures the volume of filtered air that a purifier delivers, is 234 for smoke, 248 for dust and 232 for pollen. The higher the number, the faster the machine filters air. The Association of Home Appliance Manufacturers’ air filtration standard says that an air purifier’s CADR should be equal to at least two-thirds of the room’s area. Long story short: For smoke, the Mighty should be effective in rooms as large as 350 square feet, making it suitable for most spaces.
The Coway Airmega Mighty also uses a high-efficiency particulate air filter (HEPA), which is integral to cleaning the air, according to Jill Heins, the senior director of nationwide health promotions at the American Lung Association.
“Mechanical HEPA air cleaners are designed to filter and capture particulate matter in the air,” Heins says. “Particulate matter is a leading indoor air pollutant that can cause eye, ear, nose, throat and lung irritation; asthma and COPD exacerbations; strokes and heart attacks.”
On top of including a HEPA filter, the gold standard of air purification, the Coway Mighty also has a deodorizing activated charcoal filter and a pre-filter that catches larger particles, which you have to clean every two to four weeks.
The charcoal filter doesn’t seem to do much. When my landlord redid my room with some toxic-smelling epoxy, I constantly ran my air purifier on high. And yet, the smell persisted until I had them remove the offending paste. On the other hand, it’s clear the pre-filter works because it quickly fills up with dust, debris and cat hair.
The easy-to-clean filter
Luckily, cleaning this thing is pretty easy. After removing the front cover, the pre-filter easily pops out, and depending on how dirty it is, you can either rinse it with water or vacuum the screen. I almost always opt for the vacuum because it’s easier to suck up the hair and dust — a 30-second process — and be done with it.
The only other maintenance you have to do is cleaning the air quality sensor and the air vents every two months and the front cover whenever it’s dusty. Despite almost always neglecting these steps (I know, I know), my air purifier works as well as it did when I purchased it. The only caveat I’d add is that the air quality sensor’s accuracy relies on its cleanliness, so I’d urge readers to be more careful than me.
The easy-to-use controls
It’s also easy to use. You don’t have to fuss with a ton of complicated settings or tap an annoying touchscreen to adjust the fan. Instead, the Coway has a simple control panel with five buttons, many of which you’ll hardly ever need to press. The only adjustment you might make is to the air speed, which has five settings: auto, eco and fan speeds one through three.
The first two modes are entirely automated. On auto, the fan adjusts depending on the air quality it detects using a built-in sensor. If you light a candle nearby or turn on the stove, the air purifier’s fan will adjust and hit max speed, working hard to return particulate levels back to normal. This is when the Coway Airmega Mighty is at its loudest, around 60 decibels, according to my measurements. That’s about as loud as a dishwasher.
Eco mode is like auto, except the machine stops running its fan when the sensor detects no air pollution for 30 minutes. The appeal of these two modes is obvious. Rather than having to manually adjust the settings, the air purifier’s sensor does that for you. Besides the fan speed and power buttons, the Coway also offers a timer, so you can program it to turn off in one, four or eight hours.
Its attractive, low-profile design
The Coway Airmega Mighty’s design is forgettable — in a good way. Rather than packing this thing with obnoxious blue LEDs (this isn’t a gaming computer) or adding an ugly perforated grill (see the Coway Airmega 200M), this air purifier’s design is understated, particularly when you purchase it in white. That’s a huge bonus because it will blend in with a variety of furniture and decor styles.
What I didn’t like about it
It’s expensive to run
Unfortunately, the Coway Airmega Mighty costs a pretty penny when you factor in the cost of electricity and replacement filters — but that goes for just about any air purifier. A year of Coway brand replacement filters (that’s one HEPA and two carbon filters) will cost you around $50. That’s not terrible. But once you add in the cost of electricity — I made a rough calculation using these electricity prices and this energy data — you’re looking at around $131 a year. Add in the machine itself, which hovers around $200, and you’ve spent $331 in the first year. I don’t love that, though there are ways to reduce that cost. My advice: Buy the air purifier on sale, opt for third-party filters and use eco mode.
The ionizer is unnecessary
At first, I was intrigued by the Mighty’s ionizer button, which releases electrically charged particles to remove pollutants and control odors. But ionizers also emit ozone, an unstable gas that makes up the kind of smog Los Angeles is known for. As you might expect, that’s not a good thing.
When I asked Heins for the American Lung Association’s opinion on ionizers, she said they should be avoided, adding that ozone (aka smog) is a “nose, throat and lung irritant.” The Environmental Protection Agency similarly dissuades consumers from using ionizers and ozone-emitting air cleaners. “Under certain use conditions, ion generators and other ozone-generating air cleaners can produce levels of this lung irritant significantly above levels thought harmful to human health,” the agency’s website reads. Thankfully, you can turn the Coway air purifier’s ionizer off.
How it compares
The Coway Airmega Mighty can often be found on lists of the top air purifiers on the market. That’s a testament to its quality, which can’t be overstated. But that doesn’t mean it’s the best air purifier for everyone. For example, homeowners with large open spaces and/or high ceilings should buy something with a higher CADR.
Energy Star has a helpful product finder, which allows you to search air cleaners based on room size, CADR, efficiency and more. Levoit’s Core 600S Smart Air Purifier is one option for larger spaces. Or perhaps you’re on a budget and live in a cramped dorm room. In that case, Clorox’s $60 tabletop model might be enough. As for the Coway Airmega Mighty’s peers, the Levoit Core 400S Smart Air Purifier, BlueAir 311i Max and Winix 5300-2 all have similar specs at roughly the same price point.
Regardless of what you pick, there are a few things to keep in mind when choosing an air purifier. Heins says that all air cleaners should have low-cost replacement filters, a HEPA filter, a high CADR that follows the two-thirds rule (meaning the CADR is equal to at least two-thirds of the room’s area) and a California Air Resources Board certification (which is required for it to be sold in California). You should also avoid models that advertise ultraviolet radiation, disinfection features, ionizers and ozone generators, Heins says, explaining that these features could be harmful to your health.
Bottom line
If there’s a unifying theme in this review, it’s that the Coway Airmega Mighty is truly a “set it and forget it” home appliance. You plug it in, turn it on and then forget about it — until it’s time to clean or swap a filter. If it fits in your budget and works for your space, I’d say everyone should get one — especially if you have allergies or live in a region prone to wildfires. After all, it checks all the boxes for a great air purifier, save for its ionizer feature —though that can be turned off. The only thing that would turn me against the Coway Airmega Mighty is if it broke (and it’s still going strong after two years of constant use). So for now, I won’t shut up about how much I love it.
