This is an amazing piece of equipment to say the least. I am very happy with it's performance. Though large with changeable front panels it fits right into my décor.
Upon setting up our 75i, it was immediately noticeable the clean fresh air was pure to the smell. We have gone thru a period of high pollen season but our household air became immediately fresh and enjoyable. My wife has COPD & ASMATHA thus buying a 2nd unit for our bedroom could improve our breathing while sleeping. We are extremely pleased with our purchase of these devices.
I am in love. Hobbled through two major northern CA fire seasons with sub-par air purifiers and couldn't take it anymore. I recently bought TWO 75i's, one for downstairs and one for upstairs in my 1200 square foot home, and I'm SO HAPPY! Just tonight there's a local fire, and my Alens ramped themselves up (and therefore warned me to shut my windows and doors.) When the colors change, even all the way up to red, the purifiers plow through it quickly and get them back to blue quickly. The real test (massive wildfires) is yet to come (although I'm praying the real test never happens). I feel so much safer with these babies and their 3.6 lbs of carbon per each Fresh filter, I already feel the $$ was well worth it and am kicking myself for not buying these right after the first year of horrific fires.
Very quiet! Many options for operation from ion mode to speed to automatic which is great! The only negative on this unit is that the lights are very bright while running snd are located on the top so it is hard to camouflage the unit in the room. It is a pleasing-to-the eye unit and blends in well except for the lights. This is the fourth Alen purifier we have purchased over the past 5 or so years and I like that it is warranted for life with the automatic filter subscription!