Name: Blueair Blue Signature SP3i
Brand: BLUEAIR

Blueair Blue Signature SP3i air purifier

Last verified: Aug 22, 2026

Aug 2026

Quick verdict

The Blueair Blue Signature SP3i is best suited to medium rooms where high airflow and app control are priorities. Its 321 CFM smoke CADR supports about 498 sq ft at approximately 4.8 air changes per hour. Buyers should separately evaluate filter cost, maximum-speed noise, and Blueair’s HEPASilent filtration before deciding.

Best for

Living rooms and medium bedrooms
App or Wi-Fi control

Consider alternatives if

You need a verified maximum-speed noise figure
Filter replacement interval or cost is a deciding factor
You are planning around the manufacturer coverage claim rather than CADR-based room size

Verified strengths

321 CFM smoke CADR (~498 sq ft at ~4.8 ACH)
54 dB published minimum noise
HEPASilent filtration (as published)
Wi-Fi or app control

Verified limitations or missing information

Maximum-speed noise is not in our sources
Filter replacement interval is not verified

Blueair Blue Signature SP3i overview

The Blueair Blue Signature SP3i is a medium-room air purifier with a smoke CADR of 321 CFM. Based on our CADR-based room-size method, it is suitable for approximately 498 sq ft. It includes HEPASilent filtration, 54 dB minimum noise, and Wi-Fi or app support.

Smoke CADR: 321 CFM
Recommended room size: 498 sq ft
Claimed coverage: 2250 sq ft
Minimum noise: 54 dB
Filter type: HEPASilent
Wi-Fi / app: Yes
Power: 36 W
Weight: 9.5 lb
Last verified: Aug 22, 2026

Blueair Blue Signature SP3i CADR and room size

Recommended room size is about 498 sq ft (CADR × 1.55). That is approximately 4.8 air changes per hour in a room with an eight-foot ceiling. The manufacturer figure of 2250 sq ft corresponds to about 1.1 air changes per hour at the same ceiling height and is shown separately. Our recommended room size uses approximately 4.8 air changes per hour with an eight-foot ceiling. Manufacturer coverage figures may use a lower air-change rate and are shown separately.

The manufacturer coverage claim is higher than 3× CADR, so it is not used for ranking.

Blueair Blue Signature SP3i noise level

Published minimum noise is 54 dB.

Maximum-speed noise is not in our sources.

Blueair Blue Signature SP3i filtration

Published filter type: HEPASilent.

Blueair describes HEPASilent as a combination of mechanical and electrostatic filtration. We do not independently verify particle-removal efficiency.

Filter replacement interval is not verified in our sources.

Blueair Blue Signature SP3i smart features

WiFi Smart Control, Auto Mode, Odor & Smoke Removal, AHAM Verified

Blueair Blue Signature SP3i specifications

CADR (smoke): 321 CFM
Recommended room size: 498 sq ft
Manufacturer claimed coverage: 2250 sq ft
Minimum noise: 54 dB
Filter type: HEPASilent
Power: 36 W
Weight: 9.5 lb
Wi-Fi / app: Yes

About Blueair air purifiers

Blueair models in this catalog are compared by CADR, recommended room size, noise, and filter type.

See all Blueair air purifiers

Blueair Blue Signature SP3i comparisons

Compared with the Blueair Blue Pure 211+, the Blueair Blue Signature SP3i has 8% lower CADR.

What is the CADR of the Blueair Blue Signature SP3i?

Smoke CADR is 321 CFM.

What room size is the Blueair Blue Signature SP3i suitable for?

About 498 sq ft at approximately 4.8 air changes per hour with an eight-foot ceiling.

How loud is the Blueair Blue Signature SP3i?

Minimum reported noise: 54 dB.

Does the Blueair Blue Signature SP3i have Wi-Fi?

Yes — app or Wi-Fi features are listed.

What filter does the Blueair Blue Signature SP3i use?

HEPASilent.

Methodology

Specifications are compiled from manufacturer documentation, product listings and other cited sources.

How we calculate recommended room size.

Sources

All air purifiers · Blueair air purifiers · Best air purifiers for allergies · Methodology