Blueair Blue Pure 311 Particle + Carbon Filter

Why it matters

The Blueair Blue Pure 311 Particle + Carbon Filter is a maker-original filter for the Blueair Blue Pure 311 Auto Air Purifier.

Made for Blueair's Blue Pure 311 purifiers. The model label is usually on the back or under the filter door; match it before ordering.

Construction: HEPASilent.

Replacement interval, per the maker: every 6 months. Smoke, pets and heavy use shorten that; a filter that looks gray on the intake side is due.

Blueair's Particle + Carbon version adds a carbon layer for light household odors.

It fits the Blueair Blue Pure 311 Auto Air Purifier, which its maker lists as rated for 388 square feet. A unit that runs on high in a large room loads its filter faster than the same unit on low in a bedroom.

This is the odor stage: activated carbon adsorbs smells and some gases (VOCs) until its surface fills up, and then it simply stops working, with no visible sign. Kitchens, smokers and pets fill it fastest, so replace it on the maker's interval even if it looks clean.

Use the filter made for your exact unit: purifier filters seal against their own housing, and a close-but-different filter lets air bypass the media.

Compared with the Blueair Mini Restful Replacement Filter: replacement interval every 6 months here vs every 9 months.