Blue Pure 311i Max Series AllergenBlock Filter, Genuine Replacement Filter for Allergies, Pollen, Dust, Pet Dander, Fits Blue Pure 311i Max Air Purifier

Quality filter! Busts ANY KIND of odor!

BEWARE BUYERS TO GET THE RIGHT FILTER: I bought my BLUEAIR Air Purifier in 2024 and though my Amazon Order / Invoice model description is "311i Max", when I look at the actual model number on my appliance it is the model "311i+ Max". If you unscrew the top fan assembly head from your air purifier it will show you which model you have on the label. Most folks probably did what I did and ordered based on my Amazon order description of "311i Max" which is a filter that is about 2-inches too short in height. For the "311i+ Max" you will want this filter, or comparable (which is the BLUEAIR Smoke block filter) (and it DOES NOT HELP that the Amazon size specifications are lacking or nonsensical for many of the filters); https://www.amazon.com/dp/B08KQK5P74?ref=ppx_yo2ov_dt_b_fed_asin_title

It’s exactly what I ordered and shipped quickly!

I placed the purifier with the SmokeBlock filter in a corridor for an hour, where the smell of burning was lingering strongly. It did not clear the smell of smoke at all. Beyond the corridor, the house was relatively clear. The VOCs had pooled in a small area, which this filter wasn't able to clear. For odours, I have only found the Blueair Signature purifier to be effective and produce actual clean-smelling air during and after a smoke event. If you actually have issues with smoke (for us, the above refers to mixed waste burning), I would purchase the latter purifier. If you already have the 311i, this IS an upgrade - it does a better job that the original filter overall.

The original filter seemed to clean the air but didn't do great at removing odors. I chose to give this filter a try just to see if it would make a difference. It made a complete difference! The air was completely fresh and odorless. Online there is barely any reviews or information on any of the filters and the differences they make.. From what I gathered off google and reddit basically theres the standard particle and carbon filter, a smoke block filter with extra added carbon to capture and neutralize odors and gasses, and an allergen filter which is basically the smoke block filter with an additional filter modification that has some coating to catch germs. I don’t know about all that but it definitely made the air smell and feel much fresher than the one it came with. My unit came in the box without any sort of plastic covering on the filter so that could also have caused the filter to not perform as expected. I recommend purchasing this filter, it’s a little pricey but definitely increases the overall performance of the air purifier drastically.