Blueair Signature vs Classic: Which Air Purifier Fits Your Room?

By Simone Ellery · Updated 2026-09-21T04:45:08.248Z · How we choose · How we make money

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Blue Signature™ Large Nordic Fog

$449.99 tracking this price over 2 days · 2 readings

Pros

• 455 CFM CADR and 705 sq ft coverage, the largest coverage in the Blueair Signature and Classic lineup shown
• Quiet at 23 dB, quieter than the Classic Pro CP7i (24 dB) and DustMagnet 5440i (31 dB)
• 13.2 lb, far lighter than the 32 lb Classic Pro CP7i despite covering more area
• Rated 4.5

Cons

• At $449.99 it costs $250.00 less than the Classic Pro CP7i but $150.00 more than the Blue Signature Medium Midnight and $194.00 more than the DustMagnet 5440i
• 23 dB is louder than the 19 dB Blue Signature Medium and Small models

Who it's for: Large rooms and allergy households that want the biggest coverage in the Blueair Signature line in a relatively light, quiet unit.

Check price at blueair.com

Blue Signature™ Medium Midnight

$299.99 tracking this price over 2 days · 2 readings

Pros

• Covers up to 498 sq ft
• Quiet 19 dB low setting (54 dB high)
• Rated 4.5
• At $299.99, costs $400.00 less than the Classic Pro CP7i and $44.00 more than the DustMagnet 5440i

Cons

• At 9.5 lb it is heavier than the 5.6 lb Blue Signature Small Midnight
• No CADR figure listed for this model

Who it's for: Buyers who want a quiet, mid-size Blueair Signature purifier for rooms up to 498 sq ft at $299.99.

Check price at blueair.com

Blue Signature™ Small Midnight

$179.99 tracking this price over 2 days · 2 readings

Pros

• CADR of 160 CFM and 248 sq ft coverage suit bedrooms and small rooms
• Runs at 19 dB on low, quiet enough for sleep
• Weighs just 5.6 lb, easy to move between rooms
• At $179.99 it is the cheapest of the listed models, $76.00 less than the DustMagnet 5440i and $120.00 less than the Blue Signature Medium Midnight

Cons

• 248 sq ft coverage is the smallest of the listed models
• High setting reaches 50 dB

Who it's for: Buyers wanting a quiet, lightweight air purifier for a bedroom or small room at the lowest price in this lineup.

Check price at blueair.com

Classic Pro CP7i

$699.99 tracking this price over 2 days · 2 readings

Pros

• 393 CFM CADR and 609 sq ft coverage suit large rooms
• 24 dB noise rating is quiet for its size
• 4.6 rating, the highest among the listed models
• Covers 609 sq ft for $699.99, $250 less than the only pricier option here

Cons

• At 32 lb it is the heaviest model in the lineup
• $699.99 is the highest current price among the listed products

Who it's for: Buyers with large rooms who want strong coverage and a high rating and will accept the heaviest unit and the top price.

Check price at blueair.com

DustMagnet™ 5440i

$255.99 tracking this price over 2 days · 2 readings

Check price at blueair.com

How we chose

How we chose: We lined up the listed CADR, coverage, noise, weight and current prices across the Blueair Signature and Classic models and compared them side by side.

The Blue Signature Large Nordic Fog lists 455 CFM CADR and 705 sq ft coverage at $449.99, with a listed noise level of 23 dB and a weight of 13.2 lb. The Blue Signature Medium Midnight covers 498 sq ft at $299.99 — $150.00 less than the Large Nordic Fog — and weighs 9.5 lb with a listed 19 dB. The Blue Signature Small Midnight covers 248 sq ft at $179.99, weighs 5.6 lb and lists 160 CFM CADR.

The Classic Pro CP7i lists 393 CFM CADR and 609 sq ft coverage at $699.99, which is $250.00 more than the Large Nordic Fog and $400.00 more than the Medium Midnight; it weighs 32 lb with a listed 24 dB. The DustMagnet 5440i covers 335 sq ft at $255.99, $194.00 less than the Large Nordic Fog, with a listed 31 dB and 15 lb.

Who should skip these

If your room is small, the Blue Signature Large Nordic Fog is more coverage than you need. It covers 705 sq ft and costs $449.99, which is $150.00 more than the Blue Signature Medium Midnight and $270.00 more than the Blue Signature Small Midnight. The Medium Midnight covers 498 sq ft, and the Small Midnight covers 248 sq ft.

The Classic Pro CP7i is the most expensive unit here at $699.99, and it costs $250.00 more than the Large Nordic Fog. Unless you want its 609 sq ft coverage and 4.6 rating, the lower-priced models will do the same job for less.

The DustMagnet 5440i covers 335 sq ft at $255.99, which is $44.00 more than the Medium Midnight and $76.00 more than the Small Midnight. If your space is already covered by one of those, the extra spend buys capacity you will not use.

How to choose the right one

Start with the listed coverage and match it to your room. The Blue Signature Large Nordic Fog is rated for 705 sq ft, the Classic Pro CP7i for 609 sq ft, the Blue Signature Medium Midnight for 498 sq ft, the DustMagnet 5440i for 335 sq ft, and the Blue Signature Small Midnight for 248 sq ft.

Then weigh noise and weight. The Medium Midnight and Small Midnight are both listed at 19 dB, the Large Nordic Fog at 23 dB, the Classic Pro CP7i at 24 dB, and the DustMagnet 5440i at 31 dB. On weight, the Small Midnight is 5.6 lb, the Medium Midnight 9.5 lb, the Large Nordic Fog 13.2 lb, the DustMagnet 5440i 15 lb, and the Classic Pro CP7i 32 lb.

Finally, look at the price gaps. The Large Nordic Fog costs $150.00 more than the Medium Midnight and $194.00 more than the DustMagnet 5440i. The Classic Pro CP7i costs $250.00 more than the Large Nordic Fog and $400.00 more than the Medium Midnight. The Medium Midnight costs $120.00 more than the Small Midnight, and the DustMagnet 5440i costs $76.00 more than the Small Midnight.

Questions readers ask

By Simone Ellery · Published 2026-09-21