Blue Pure 211i Max
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I have a blueair 211i and 2 311is and I love them. I have noticed a significant decrease in dust and allergy symptoms. I recommend getting at least one for the bedroom and one big one for any open areas.
Blueair.com, Swedish, excellent products.
I also have two blue air purifiers for large rooms. 2 story house. Blue Pure 211i Max Some limited information through the HA integration. There purifiers were rated top at consumer reports and we are very happy with them. No more nasty dog smell in our bedroom.
We love ours. I can spritz something like hair product or insect repellent in the next room and it will immediately kick on.
We have this one: https://www.blueair.com/products/blue-pure-211i-max
I googled the tests CBC marketplace did on this quickly. The BlueAir **significantly** outperformed a single furnace filter (about 2.5x better) and all other tested brands. Single furnace filter was twice as effective as Dyson. [Source.](https://www.cbc.ca/news/business/portable-air-purifier-tests-marketplace-1.5900782) Furnace filter will probably work great. Don't waste money on a dyson. BlueAir is HQed in Sweden. It is owned by UniLever, which is HQed in the UK. So, BlueAir is at least not American.
Only some blue air models have ionizers. ~~Most/the most common ones do not.~~ The CADR for the 211i max (which I only pick because I have) does not have an ionizer and still rates ~4x a single Merv 11 filter on a box fan. I still think the Merv on a box fan is great. I only use BlueAir because I know it's effective while also being pretty. I also like the pre-filter for pet hair. Edit: I have learned that it apparently does have an ionizer, but, it's CARB compliant and has passed many other tests that certify it's not producing ozone in any amount that could possibly be dangerous. I think people just want to dunk on it (and use words like ionizing [which we should be concerned about] with no nuance) because they're expensive. But it still works very well and is safe.
Blue air. My wife suffers of airborne allergies, and these air purifiers practically eliminated her allergy episodes at home. We know they worked since a couple of times we have tried generic filter replacements and my wife allergies were back, but disappear again as soon as we bought the original brand name filter replacement.
We have the Blue pure 511 for our bedroom and the Blue pure 211i Max for of living room-kitchen (open concept).
Most will be loud, on full speed and most will have only 3 speeds. You want one with variable speeds, using a slider in the app. My BlueAir 211i Max does it.
We have the 211i Max and are happy with it.
I have a Blueair Blue Pure 211i Max and wouldn't necessarily recommend it. The PM sensors frequently don't update (both in HA and the BlueAir app) even though it shows on the purifiers display. The integration provided via HACS also behaves a little oddly with my model at least - if I turn on the purifier using a dashboard toggle, it overrides the purifier mode to manual and sets the fan to 50%. A previous integration (unfortunately no longer supported) left all the settings as-is when I turned it off/on.
We love our BlueAir filters. We have a 211i Max for our main floor (overkill) and a 411i max for our upstairs. Would recommend them to anyone!