If your bedroom or nursery is about 14 by 15 feet or smaller, Coway’s new Airmega Mighty2 Mini has enough airflow for it. In a bigger room, the full-size Mighty2 is worth its extra $100, because the Mini cleans only about 60 percent as much air. Coway put the Mini on sale on October 15 at $169.99. The 1,043 square feet on its product page assumes one pass of the room’s air an hour. The industry’s sizing rule asks for about five.
How much air the Mini moves
Coway lists the Mini’s clean air delivery rate (CADR, the cubic feet of cleaned air a purifier puts out each minute, or cfm) at 143 for smoke. The Airmega Mighty2 is listed at 240. The Mini’s dust and pollen ratings are lower too.
By Coway’s count the Mini is 40 percent smaller than the Mighty2, and the dimensions bear that out. Worked out from the published dimensions, the Mini’s box has about 42 percent less volume. Its smoke CADR is about 40 percent lower, so the airflow shrank along with the cabinet.
Those are Coway’s figures, and we haven’t used a Mini. AHAM, the appliance makers’ association that runs the CADR program, keeps a directory of lab-verified models for the US and Canada. It showed no Coway model when we searched it on October 20.
Room size by AHAM’s rule
AHAM’s rule of thumb asks for a smoke CADR of at least two-thirds of the room’s floor area. Under an 8-foot ceiling, the height Coway’s manual assumes for its one-pass figures, that works out to about five air changes an hour.
By that rule, the Mini suits rooms up to about 215 square feet. That is a bedroom of 14 by 15 feet. The Mighty2 reaches about 360 square feet. Coway’s one-pass figures are about five times larger for both, so use them only to compare one Coway with another. A ceiling above 8 feet shrinks every one of these room sizes.
One filter set a year
Coway’s launch announcement says the Mini’s filter lasts six months. Its product page gives six months for the carbon filter and a year for the HEPA filter. The replacement filter’s own page lists six to 12 months for both.
The user manual lists three parts, each with its own schedule:
- Pre-filter: vacuum or wipe it every two to four weeks.
- Custom filter, a carbon sheet for odors: replace it every six months.
- HEPA filter: replace it once a year.
A spare carbon sheet comes in the box, so the first year is covered. Coway’s $49.99 replacement set holds one HEPA filter and two carbon sheets. One set a year keeps the Mini on schedule after that.
That is the layout of the original Mighty, which pairs a yearly HEPA filter with carbon filters changed at about six months. The Mighty2 moved to a single combined filter that costs $69.99 and lasts a year. According to Coway’s filter page, Mini filters fit neither of the other two.
Three years of ownership
Coway’s store listed the Mini at $169.99 and the Mighty2 at $269.99 on October 20, 2026. Each needs two filter purchases in its first three years, one after each of the first two years. By our arithmetic, that puts the Mini at $269.97 over three years and the Mighty2 at $409.97.
Three years is also how long Coway covers the Mini’s motor and electronics. The manual gives other internal parts one year, a split the launch announcement’s “three-year limited warranty” leaves out.
Per unit of clean air, the Mighty2 is a little cheaper. Its three-year cost comes to about $1.71 for each cfm of smoke CADR, and the Mini’s to about $1.89. So the $140 the Mini saves holds up only in a room its airflow can cover on its own.
Noise, power and the sensor
The Mini isn’t quieter than the Mighty2 on its lowest setting. Coway lists 19.2 dB for the Mini and 19 dB for the Mighty2, and the announcement compares the Mini’s figure only with other brands. At top speed the two are a decibel apart.
Coway rates the Mini’s power draw at up to 32 watts and the Mighty2’s at 56. The Mini’s particle sensor reads fine particles, known as PM2.5, and shows the result as one of four colors. The Mighty2’s laser sensor also counts smaller and larger particles and shows a number.
In Smart mode, the Mini switches to Sleep after three minutes of darkness. The manual says five minutes of light, or any button press, wakes it.
Coway’s microplastics claim rests on a lab test using plastic beads 0.3 microns across, run at Turbo speed. That is the particle size the HEPA rating covers, so the result shows the HEPA filter doing its usual job. The test chamber held about as much air as a 130-square-foot room with an 8-foot ceiling.
Which Coway for which room
Measure the room before you choose. Up to about 215 square feet, the Mini covers it by AHAM’s rule and costs $140 less over three years. In a larger bedroom or a living room of up to about 360 square feet, the Mighty2 is the one that keeps up. An original Mighty already running in a bedroom should stay there, since its smoke CADR of 233 is well above the Mini’s.
