I've been using the Coway Airmega ProX air purifier for a month and it performs better than it looks

If you’re after the best air purifier that focuses purely on power and not so much aesthetic appeal or price, then the Coway Airmega ProX is worth a look.

Big and heavy, Coway’s Airmega ProX is powerful enough to clear the air in rooms large and small while getting rid of pollen, smells and germs like no other room air purifier. The three-stage filtration process uses activated charcoal and two HEPA filters so that it can work with areas as large as over 4,000 square feet – enough air-cleaning potential for an apartment or small house. Plus, its hidden handles and wheels allow it to be rolled easily from room to room.

As good as Airmega ProX is though, it lacks any app, remote control or compatibility with Amazon Alexa, Google Assistant and Apple’s HomeKit. Plus, it's expensive to start with and the Airmega ProX’s filter changes can cost three times what the competition costs.

Read our review to find out if the Airmega ProX’s clean air comes at too high a price.

Coway Airmega ProX review: Price and availability

With a list price of $999, Coway’s Airmega ProX is not only the company’s flagship air filter but one of the most expensive room air cleaning devices you can get. It's slightly cheaper at $849 on Amazon.

Its HEPA filters cost $199 per set versus $50 per change for the competition and should be changed once a year. Often discounted by 10 percent to $179 if you buy two sets at a time (for a total of four HEPA filters), automatic delivery is available.

Coway Airmega ProX review: Design

As big as room air purifiers get these days, the 36.6 x 24.3 x 18.9 inch Airmega ProX is about the size of a small refrigerator and 10 times bigger than the diminutive AirThings Renew air cleaner.

In other words, its bulk can dominate a room, but the Airmega ProX’s rectangular shape means that it will fit better into a room’s corner than round designs like Dreo’s Air Purifer Tower Fan MC710S.

Designed and manufactured in Korea, Airmega ProX is available in white or mocha beige. At over 50 pounds, it’s a lot to lug around, although its hidden handles and lockable wheels make lifting and sliding easier.

It was just as easy to move it from one corner of the room to another as to push it from the dining room to a child’s bedroom but can be a chore lugging it on stairs. Unlike the AirThings Renew, it can’t be wall-mounted and lacks a coil-up cord compartment but the AC cord can be detached during storage

The Airmega ProX air purifier’s internal sensors measure 1-, 5- and 10-micron particles that determine how hard the air filter works in Auto mode. It doesn’t, however, work with external sensors, the way Renew can be incorporated into the AirThings landscape and its View Plus desktop console.

Coway Airmega ProX review: Ease of use

I found the Airmega ProX’s onboard control panel to be excellent and user-friendly. It not only shows the current particulate level, but its LED air quality dot glows blue when the air is good, while light green is for moderate and yellow for unhealthy air. Red indicates very unhealthy air and a warning to leave the room.

In addition to indicators for when it’s time to clean the prefilter and change the main filter, the Airmega ProX’s panel also shows whether it’s in Eco, Silent, Turbo or Auto mode. Its choice of three airflow speeds is adequate but I prefer the flexibility that comes with five or more fan speeds for balancing air flow and noise level.

However, as much as I liked the Airmega ProX’s huge air flow, I was disappointed that it lacked a remote control and can’t be used with Coway’s IoCare app, Alexa, Home Kit or Google Assistant. Because it starts in Auto mode, I was able to jury rig a crude remote control by plugging the air filter into a Kasa Mini Smart Plug. I can’t adjust anything, but I can remotely turn the filter on and off.

Cleaned air flows out of the unit’s top but it lacks louvers or the ability to oscillate sending filtered air side-to-side as the MC710S can. The Airmega ProX’s Clean Air Deliver Rate (CADR) score is three-times higher than the AirThings Renew device at 580 cubic feet per minute for dust, 568 ft³/min for smoke and 450 ft³/min for pollen. Capable of cleansing the air once every hour for a 4,253 square foot room or every 30 minutes for a 2,126 square foot room, it’s the rare room-sized air filtration system powerful enough for a small or mid-sized house.

Coway Airmega ProX review: Performance

After unboxing the Airmega ProX’s large box, I plugged it in next to an AC floor vent in my 25 x 12 foot office to clean and circulate the room’s air. It started in Auto mode.

There was plaster and paint work being done in an adjacent room and the Airmega ProX’s Auto mode compensated for the extra airborne dust; when the air is clean enough, it goes into power-saving Eco mode. The control panel showed that the particulate level topped out at 66 micrograms per cubic meter (μgr/m³) and its yellow warning light glowed. It soon returned to 1 or 2 μgr/m³. I could hear it working hard at times but otherwise it was quiet.

At its three fan settings, the Airmega ProX shows the air handling power of its dual fan approach with air speeds of 5.6 miles per hour, 8.1 mph and 13.7 mph measured 36 inches above the vent. That’s significantly more breeze than other room air cleaners deliver.

On the other hand, it came at the cost of slurping electricity rather than sipping it with power use of 12.2 watts, 27.0 watts and 62.4 watts at its three fan settings. If it runs at its minimal setting 24/7 and you pay the national average of 16 cents per kilowatt hour of electricity, it will add up to an annual electricity bill of $17.10 – three to five times what other air cleaners cost to use.

Still, I found the Airmega ProX surprisingly quiet compared to its peers, which deliver less air flow. Measuring 36-inches from the vent, the Airmega ProX produced noise levels of 40.1dBA, 43.3 dBA and 50.4dBA at its three fan settings in a room with a background noise level of 37.1dBA. That’s significantly hushed compared to the Renew and MC710’s 55.1 dBA and 55.0 dBA at full blast.

Despite having two filters to change, this was straightforward. After taking off the prefilter, I pulled on the fabric tabs to remove each HEPA filter. The new ones quickly popped into place. Coway covers the parts most likely to break (the motor and electronics) for five years. Everything else has a one year warranty, which is on a level with its competition.

Coway Airmega ProX review: Verdict

Coway’s Airmega ProX may be big and heavy (and pricey), but it is the best choice for clearing the air in a large room or even a small house. Its dual- fan approach, activated charcoal and HEPA filtration can cover a lot of territory but it lacks an app or voice control with Alexa, Google Assistant or Home Kit.

Bear in mind, it's expensive to purchase and use. Plus, its filters cost three-times that of other air cleaners. Still, the Airmega ProX is the best way to keep the air clean in a large area.