Blueair Blue Signature vs IQAir Atem X
Two of the large-room air purifiers in our best large-room air purifiers: coway, blueair, levoit, winix, iqair & more comparison, lined up spec by spec. Every figure comes from the manufacturer pages linked below, and the scores use the same published formula as the full ranking.
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Best for: 455 CFM from a 13.2 lb side-outlet unit
Check price at AmazonBest for: IQAir's large round purifier, 15 dB on low
Check price at AmazonSpec-by-spec comparison
Green marks the better published figure. "Not listed" means the manufacturer doesn't publish it.
| Spec | Blueair Blue Signature | IQAir Atem X | Weight |
|---|---|---|---|
| Smoke CADRSmoke is the hardest of the three AHAM CADR tests, so we use it when listed. Levoit lists one headline CADR, and we use that. Shark, Honeywell, Molekule and IQAir don't publish an AHAM CADR, so those cells are blank and score at the lowest published value in the category. | 455 CFM | Not listed | 40% |
| CADR per wattComputed by us: smoke CADR divided by the maker's rated or maximum power. Higher means more clean air for the electricity, which matters for a machine that runs all day. | 10.8 CFM/W | Not listed | 15% |
| Quietest settingThe lowest listed noise level, usually sleep mode. Makers measure at different distances, so treat differences of 1–2 dB as a tie. | 23 dB | 15 dB | 10% |
| Loudest settingNoise at top speed, which is what you hear when you run it hard for smoke or cooking. Left blank when the maker lists only the minimum. | 55 dB | 58 dB | 10% |
| Carbon or odor stage includedYes when the filter in the box includes an activated-carbon or deodorization stage, per the maker. HEPA alone traps particles but not odors or gases. | Yes | No | 10% |
| Main filter lifeThe maker's 'up to' figure for the main HEPA filter. Makers assume different daily run times (noted on each product), so this is a rough guide to running costs. | 12 months | Not listed | 15% |
| CADR (smoke / dust / pollen) | 455 / 434 / 450 | Not listed | info |
| Recommended room | 705 ft² (4.8 ACH) | Not listed | info |
| Filter | Particle + carbon | Not listed | info |
| Filter life | Up to 1 year (RealTrack) | Not listed | info |
| Noise | 23–55 dB | 15–58 dB(A) at 3.3 ft | info |
| Power | 3.5–42 W | 6–86 W across 8 speeds | info |
| Weight | 13.2 lb | 28.7 lb | info |
| AHAM CADR | Not listed | Not published by the maker | info |
| IQAir CADR per speed | Not listed | 65–471 cfm (IQAir's own figures, not AHAM) | info |
| Coverage | Not listed | Up to 1,650 ft² (2 air changes/hr, IQAir) | info |
| Sensors | Not listed | PM2.5, CO2, temperature, humidity | info |
| AirPick score | 7.3/10 | 2.1/10 | 100% |
Where each one comes out ahead
Blueair Blue Signature
Better published figure on: Loudest setting, Carbon or odor stage included.
What we like
- 10.8 CFM per watt, the best here
- 455 CFM at 13.2 lb
Watch out for
- 55 dB at top speed
IQAir Atem X
Better published figure on: Quietest setting.
What we like
- 15 dB(A) on its lowest speed
- CO2 sensor
Watch out for
- No AHAM CADR
- No carbon stage listed in the US specs
Verdict
Atem X goes quieter on low (15 vs 23 dB) but has no AHAM CADR and no listed carbon stage. Blue Signature lists 455 CFM smoke and particle + carbon filtration.
- Blueair Blue Signature: Blueair: Blue Signature
- IQAir Atem X: IQAir: Atem X