The Blueair Blue Signature Large is a high-end air purifier designed for large rooms. It pulls double duty as a small table, with a chic design that's meant to blend into the background of any living room or office. There are a number of available pre-filter colors to match your decor, and even available legs to further sell the illusion. It features a multi-stage filtration system with ionization technology, which is an integrated system that BlueAir dubs HEPASilent. Additional features include companion app connectivity and a touchscreen interface that also shows current PM2.5 levels.
Our Verdict
The Blueair Blue Signature Large is a fantastic choice for pet owners, with an important caveat. At its highest fan speed, its particle filtration rate is enough to keep particle levels low even when running as a standalone unit in an open-concept living area or a studio apartment. It can be a little loud at its fastest speed, so if your pet is especially skittish, lowering the fan speed to a quieter setting still produces a high enough particle filtration for it to operate effectively within large rooms. Its laser particle sensor also allows it to monitor air quality in real time and adjust its fan speed automatically as needed, so you won't need to babysit the unit while you're away from home. Beyond that, there are additional layers of activated carbon and mineral to reduce any odors from your furry friends. Unfortunately, its ionizer system can't be disabled. Since this system produces a small amount of ozone while running, it can present a respiratory hazard for particularly sensitive pets.
Exceptionally high maximum particle filtration rate.
Can function as a piece of functional furniture.
Quiet enough for overnight use in bedrooms and other shared living spaces.
Automatically adjusts fan speed as air quality changes.
Ionizer can't be disabled.
The Blueair Blue Signature Large is an excellent option for use in bedrooms. It runs extremely quietly at lower fan speeds, and it shouldn't wake the lightest of sleepers. There's also a night mode that turns off the display to reduce distractions. Even at lower fan speeds, it's still very effective in trapping airborne pollutants in the largest of bedrooms. While the Signature Large has a wide footprint, it can be used as a nightstand, thanks to its flat top where you can set aside your phone, glasses, and maybe even a small potted plant or alarm clock. Unlike many other air purifiers with ionization systems, the Blueair's ionization system can't be disabled. This system is intended to help attract airborne pollutants to the filter, but it also produces a small amount of ozone, a known respiratory irritant. While the amount of ozone this system produces is certified to fall within safe limits, this can still be a deal breaker for those who suffer adverse reactions from any level of ozone in the air, especially in a bedroom where the purifier will run overnight.
Can function as a piece of functional furniture.
Particle filtration rate at lower, quieter fan speed settings remains sufficient for bigger spaces.
Quiet enough for overnight use in bedrooms and other shared living spaces.
Automatically adjusts fan speed as air quality changes.
Ionizer can't be disabled.
Footprint is a little bulky.
The Blueair Blue Signature Large’s particle filtration rate is incredible. At its highest fan speed, its clean air delivery rate (CADR) is sufficient to maintain a high level of air quality within really large spaces, like open-concept living areas or larger basements. While there is a drop in performance at lower, quieter fan speeds, its CADR is still sufficient for it to operate effectively within larger kitchens, living rooms, or dining areas.
Exceptionally high maximum particle filtration rate.
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Differences Between Sizes And Variants
The Blueair Blue Signature Large is available in two chassis colors: Nordic Fog (light grey) and Midnight (dark blue). We bought and tested a unit in the Nordic Fog finish, though we fully expect the Midnight version to perform identically. For those interested, here's the product label for our test unit.
If you come across another variant of this air purifier, let us know in the comments below so that we can update our review.
Popular Air Purifier Comparisons
The Blueair Blue Signature Large is a high-end air purifier intended for use in large rooms. It's a standout performer overall, with a high clean air delivery rate that exceeds that of even more expensive units like the NuWave OxyPure and the Dyson Purifier Big+Quiet Formaldehyde BP04, all the while taking up less space and having a design that blends into your home a lot more seamlessly. It runs very quietly overall, and lower fan speeds still produce very good particle filtration performance. The one potential issue for some buyers is its ionization feature; unlike the Winix C610's PlasmaWave bipolar ionization system, the Blueair's system can't be disabled. The Blueair's ionizer feature is meant to improve particle filtration performance, but it also produces a small amount of ozone while running, which is a respiratory irritant. While its ozone production is certified to land within safe limits, it can still present an issue for those who are particularly sensitive.
If you're interested in alternatives, check out our recommendations for the best air purifiers, the best air purifiers for pets, and the best air purifiers for bedrooms.
The Blueair Blue Signature Large is a better-performing air purifier than the NuWave OxyPure. The Blueair has a higher maximum clean air delivery rate, allowing it to perform more effectively in larger spaces, and also has a higher particle filtration rate at quieter fan speeds. Beyond that, the Blueair is quieter across its highest and lowest fan speed settings. Lastly, the Blueair's furniture-like design blends into the background more seamlessly than the very bulky Nuwave, and can serve as a small table. With that being said, it's important to note that while the Blueair's ionizer system is rated to produce a negligible amount of ozone, the system can't be disabled, which can be a respiratory hazard for people and pets who suffer from ozone sensitivity. The Nuwave suffers from no such issue.
The Blueair Blue Signature Large has a slight overall edge in performance over the Levoit Core 600S. The Blueair has a slightly higher particle filtration rate when using its highest fan speed setting, as well as when it's been configured to run quietly, making it marginally more effective in larger living areas. The Blueair is also noticeably quieter and is a better option for rooms with a lot of foot traffic. In terms of footprint, the Levoit is narrower but taller, and unlike the Blueair, it can't be used as a table. The one potentially significant issue with the Blueair is its ionizer system, which can't be turned off. This system's ozone production is rated to fall within safe limits, but it still could be a respiratory irritant for some people and pets.
The Dyson Purifier Big+Quiet Formaldehyde BP04 and Blueair Blue Signature Large are both premium air purifiers intended for larger spaces, but the Blueair delivers better performance across the board. At both units' highest fan speeds, the Blueair is more than twice as fast when it comes to providing the same level of air quality within a similarly sized room. While the Blueair has a slightly wider footprint, it's also considerably shorter, and its flat top allows it to double as a functional end table. Unfortunately, the Blueair's ionizer system can't be disabled. Since this feature releases ozone as an operating byproduct, this can be an issue for those who suffer from ozone sensitivity.
Test Results
This air purifier is advertised to have a seven-stage filtration system. However, closer inspection finds only four physical filters, along with an ionization system:
- Pre-filter (Stage 1): Exterior filter for trapping fine hair and larger dust and dirt particles.
- Particle & Carbon Filter (Stages 2 & 3): Primary filter for trapping airborne dust, pollutants, volatile organic compounds, and gases.
- Mineral layer (Stage 4): For minimizing odors.
The additional filters are layers sandwiched within the existing filters, and thus aren't counted separately. In addition, while the unit's filtration system uses the name HEPASilent and is claimed to exceed the HEPA standard, it should be noted that none of the individual filters carry a HEPA certification.
As far as maintenance goes, you'll need to vacuum the pre-filter periodically, or whenever you notice that it's dusty or dirty, in order to maintain peak performance. Replacements are available in a number of different colors to match your decor.
The primary particle and carbon filter have an estimated service life of one year, though that can vary. Filter wear is estimated using the brand's RealTrack technology, which is advertised to monitor fan speed, usage time, and air quality. When that system deems it time to replace the filter, a status light on the unit's display illuminates. Alternatively, if you've paired your air purifier to your smartphone using the Blueair companion app, you'll receive a pop-up notification as well. Like the pre-filter, replacement primary filters are available online.
This air purifier features a particle ionizer system, which works a little differently than some other systems: the Blueair ionizer releases negative ions that bond to airborne pollutants, which are then drawn towards the electrostatically charged filter layer, all in a bid to enhance particle filtration performance. Like most ionizer systems, it also produces ozone, a respiratory irritant, as an operating byproduct. While the level of ozone this system produces is AHAM-certified to fall within safe limits, those who are particularly sensitive to ozone, as well as some pets, may still notice its effects. This ionizer system also can't be disabled.
