It's a matter of room size.
Each Blueair model uses HEPASilent™ filtration technology to achieve 99.97% efficiency at 0.1 micron. But filter performance is only part of the picture. Your air purifier must also be able to process the volume of air in the room where it operates. You need only compare the size of your room to the room size capacities listed below.
Our room size recommendations are based on testing by the Association of Home Appliance Manufacturers (AHAM), an independent industry organization that rates air cleaners for overall performance. Choose the system that matches your room size. All room sizes assume an 8-foot (2.4 meter) ceiling; if your ceilings are higher, choose the system that matches the next larger room size.
Room Size Best Blueair Option
Up to 72m2 (775 sq.ft.) Blueair Classic 680i Blueair Classic 605
Up to 40m2 (434 sq.ft.) Blueair Classic 480i Blueair Classic 405
Up to 26 m2 (279 sq.ft.) Blueair Classic 280i Blueair Classic 205 Blueair Classic 203 Slim
All units come equipped with HEPASilent™ Particle Filters. Optional SmokeStop™ Filters are available for people who smoke or who live with a smoker.
You can also compare all new 'Classic' Models below: