LEVOIT Core 400S vs Coway Airmega Mighty AP-1512HH

These two machines occupy the same slot in almost every buying guide written about air purifiers, and they are usually separated on price, look or brand loyalty. There is a more useful separation available.

Electricity costs on this page use 18.34¢ per kWh, the U.S. average residential price for June 2026 from the U.S. Energy Information Administration, Electric Power Monthly, Table 5.3. Your rate is on your bill and is probably not this one; multiply the kWh figure by your own rate and you have your number.

231 versus 233 smoke CADR is not a difference. 358 versus 361 certified square feet is not a difference. Anyone telling you one of these clears a room meaningfully faster than the other is inventing a distinction. Both are correctly sized for a room of roughly 350 square feet under AHAM’s two-thirds rule, and both will disappoint anyone who bought on the 1,700-square-foot headline.

77 watts against 38 is the single largest difference between these machines. Coway publishes the figure openly, to its credit. For a purifier that runs continuously — which is what a pet household needs — double the draw is double the electricity bill for the same air.

ENERGY STAR certifies the Core 400S at 237 kWh a year, or $43. Coway does not publish a certified annual figure for the Mighty, and we are not going to compute one from wattage and pretend it is equivalent — the certified number contains a duty-cycle assumption that a back-of-envelope calculation does not.

This is the part that decides it for us. The Core 400S is listed in EPA’s ENERGY STAR room air cleaner database, which requires testing to ANSI/AHAM AC-1 through an EPA-recognized certification body and additionally publishes measured ozone emissions and certified annual energy use. You can look it up right now.

The AP-1512HH is in neither that database nor AHAM’s directory. Coway’s numbers may be entirely accurate — the company is reputable and its figures are internally consistent with AHAM’s own room-size formula. But “probably accurate” and “independently verified” are different states of evidence, and one of them you can check.

If your priority is cost per unit of air, both of these are beaten by the Honeywell HPA4300: 229 certified smoke CADR on 31 watts, ENERGY STAR verified, 0.00 ppb ozone, and a filter the register classifies HEPA rather than HEPA-Type. That is within 2% of both machines on output, at 40% of the Coway’s power draw, with better filter classification than either.

If your room is materially larger than 350 square feet, buy neither and size properly — the calculator will tell you the CADR you need in about ten seconds.