We live in southern Marin County, California, just north of the Golden Gate Bridge.  California has endured terrible fires the past few months, and wind patterns have brought us much smoke and ash.  We have installed three (3) Blue Pure  211+ air purifiers: 1 on the Primary Bedroom Suite, 1 in the Living Room/Dining Room floor, and 1 in the guest suite.  The 211+ have each worked continuously and effectively, and have lowered the AQI inside my house to a range of only 1 to 5 AQI, while it ranged between 80 to 230 outdoors.  My experience has been "10 out of 10-".