Air purifier for a 500 sq ft room
Minimum smoke CADR: 333 cfm with an 8 ft ceiling, 375 cfm at 9 ft, 417 cfm at 10 ft.
Based on AHAM's 2/3 rule (smoke CADR ≥ 2/3 of floor area, scaled up for ceilings above 8 ft). For wildfire smoke or allergies, many people size up; the "headroom" column shows models with at least 50% more CADR than the minimum.
26 qualifying models, cheapest to run first
| Model | Smoke CADR (cfm) | ENERGY STAR room size (sq ft) | Energy use (kWh/yr) | Est. electricity/yr* | Headroom |
|---|---|---|---|---|---|
| Rainbow Brisk Box Ultra | 370 | 574 | 94 | $17.21 | 11% over minimum |
| Blueair 3631101000 | 356 | 552 | 210 | $38.45 | 7% over minimum |
| Blueair 3432111100 | 339 | 525 | 227 | $41.56 | 2% over minimum |
| Blueair 4312111000 | 455 | 705 | 235 | $43.03 | 36% over minimum |
| Coway AP-3018B | 413 | 640 | 235 | $43.03 | 24% over minimum |
| Blueair 3613111100 | 443 | 687 | 259 | $47.42 | 33% over minimum |
| Bosch Air 6000 | 339 | 525 | 289 | $52.92 | 2% over minimum |
| IQAir ATEM E | 369 | 572 | 295 | $54.01 | 11% over minimum |
| Alen BreatheSmart 75i_V2 | 370 | 574 | 304 | $55.66 | 11% over minimum |
| Cuckoo CAC-D2020FW | 382 | 592 | 316 | $57.86 | 15% over minimum |
| Coway Airmega ProX | 577 | 894 | 335 | $61.34 | 73% over minimum |
| Blueair 6712211000 | 393 | 609 | 336 | $61.52 | 18% over minimum |
| Midea KJ600G-RX600A | 366 | 567 | 341 | $62.44 | 10% over minimum |
| Sharp KJ600F-LM1-SH | 366 | 567 | 341 | $62.44 | 10% over minimum |
| Coway Airmega 350 | 360 | 558 | 344 | $62.99 | 8% over minimum |
| Blueair Pure 211+ | 348 | 539 | 350 | $64.08 | 4% over minimum |
| Coway Airmega 400 | 376 | 583 | 366 | $67.01 | 13% over minimum |
| Coway AP-2425H | 378 | 586 | 366 | $67.01 | 13% over minimum |
| Levoit LAP-C601S-WUS | 391 | 606 | 387 | $70.86 | 17% over minimum |
| Cuckoo CAC-AH2810FNW | 455 | 705 | 388 | $71.04 | 36% over minimum |
| Coway Airmega 450 | 443 | 687 | 389 | $71.23 | 33% over minimum |
| Levoit LAP-C601S-WUSR | 394 | 611 | 389 | $71.23 | 18% over minimum |
| AirDoctor AD4000 | 370 | 574 | 396.2 | $72.54 | 11% over minimum |
| Coway Airmega 450S | 443 | 687 | 399 | $73.06 | 33% over minimum |
| Cuckoo CAC-F3010FW | 552 | 856 | 406 | $74.34 | 66% over minimum |
| Winix Tower XQ | 461 | 715 | 486 | $88.99 | 38% over minimum |
*Estimate: ENERGY STAR annual kWh × U.S. average residential rate 18.31¢/kWh (EIA, July 2026 (preliminary)). ENERGY STAR's annual figure assumes 16 hours/day of operation under the DOE test procedure.
2 of these have at least 50% headroom. Not sure of your room size? Use the room calculator.
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