LEVOIT Air Purifiers for Home Large Room Up to 3175 Sq. Ft with Smart WiFi, PM2.5 Monitor, HEPA Sleep Mode, 3-in-1 Filter for Smoke, Pet Allergies, Dust and Odor, Alexa Control, Core 600S-P, White

I've been using air purifiers in my house for at least 15 years now. Every room has one, and it has kept me from having to really dust. Being a single father for most of those years, until my kid graduated and moved out a couple of years ago, not having to do a lot of dusting is a high priority for me...All of them are way oversized for what I need, since I have large smart ones in each bedroom that claim the ability to support like 1500 square feet. But I like the smart, wifi connected ones. I also like the ones with the auto sensing feature so they can adjust their own speeds as needed. So I went for features rather than sizing correctly for each room.Thus, when it was time to get another, and I looked around, this seemed to be a good fit without getting models that cost way too much. I have an Air+Health, and an Aeris, both which are like 3 or 4 times as expensive. And neither of which has ever justified that cost in my experience. Especially now that Aeris was bought out by iRobot and the app won't even work anymore... One more reason to go this route.I got this one a day before I also grabbed a Core 200S for my bathroom - the only one I have that is not capable of auto sensing.This one is dead silent on auto. On speed 1 of 4, it's a very quiet fan noise, even from 5 feet away, which is how far it is from my dining table chair. 2 is not much worse, and even 3 is more than acceptable. 3 sounds like many other ones I've seen would be at a lower setting. 4, of course, is loud, but again, it's loud compared to itself. Compared to, say, my Aeris, Winix, or my Air+Health purifiers, this one has the least obnoxious sound level on the highest setting.I like the ability to schedule things. I let it run at a higher level at night while I sleep since the noise will not bother me at the total opposite end of the house. And even if I did her it, at that point it would be white noise, which I often sleep to anyway due to obnoxious neighbors.The auto setting seems to be spot on with the other ones I have that cost three or four times as much as this. I really never notice it going up - until I cook burgers on the stove. Doesn't matter what else I do with ground beef, tacos or anything else, nothing cares. I cook hamburgers? Suddenly the purifiers in my kitchen, dining room, and great room (big open concept here so these three rooms are one large room that's half of my house) all spin up, show red and are doing their best to cope with whatever it is that my hamburger cooking is doing to my poor indoor air quality. And this one does not lag behind or anything. So you're not getting a lesser quality detection on this one simply because you are not spending such a ridiculous amount.My only real complaint is that the display is so recessed on the top. So if you're sitting across the room you have absolutely NO visible sign of status. And if it's on auto you can't even tell if it's turned on or not since it's so quiet if it isn't sensing something in the air and cranking up the air filtering.But the app works, unlike the Aeris ones now, and the unit is unobtrusive unless you REALLY make an effort.For the price, you can't beat it. And for the price, it beats ones that cost several times its cost.Update - I threw out the thousand dollar Aeris since the app stopped working, replaced it with this. Now I'm replacing two Winix AM90's that worked fine until recently, and are having app issues of their own. One I had going without issues for about 4 years, the other was just pulled out of the box at the same time I ordered my first one of these. So I'll end up now with my home having 5 of the 7 air purifiers in it all being Levoit...

I have owned this product for less than 24 hours as of this writing. More updates as I have more to say/remember to do them. Also, I will be very verbose, the sort of in-depth information I want when I am researching products over $99 for purchase, so you really know what's going on. Hopefully it helps, but it may be TL;DR for some.My background: I am not a smoker and never have been. I was raised by a chain smoker and have spent the majority of my life around second hand smoke from parents, family and friends. I have stress induced asthma and have also been through experimental chemotherapy that has apparently permanently damaged my lungs. Over time, my lungs are slowly degrading, and as they do I become more and more sensitive to more and more things, which trigger my lungs to get irritated and produce phlegm to coat my lungs and prevent the irritation, which causes me to cough more and more over time. (It has been a lot of fun having this sort of lung disorder during the pandemic, let me tell you.)"Well, why don't you see a doctor then?" you may reasonably ask. My experience with doctors in the past has consisted of watching both my mother and grandmother die with (no joke) 30+ prescriptions each all at once (with 3 to 5 doctors all prescribing simultaneously and admitting to me in private that A) they were not consulting with one another, and B) nobody on earth could possibly keep track of the side effects of so many prescriptions at once), and my uncle wasn't far off that number when he died. I also have repeated personal experience with the medical industry that strongly supports my experience and belief that going to the doctor is going to be a financially insane choice (whether or not I have insurance) that I get little to nothing out of regardless. So I choose to avoid doctors and the medical/drug big business establishment like the plague whenever possible.When I realized recently that my lungs were noticeably irritated all the time when I was in my own home, but I was fine if I went outside, I decided it was time to step up my game. Enter this unit, which I researched before buying.My unit is brand new, not a returned unit. Upon turning it on, it told me that my air in all areas of the house tested was as good as it gets, with a reading of 001. This did not please me, because I know it's nowhere near that good. So I did an update of the firmware to see if that would fix the issue, and it did. The new display read 005, which was significantly lower than I expected, but the unit reduced that to 3, then 2, then 1 relatively quickly.Within about 15 minutes, the air in my (door closed) office started to smell noticeably different. Lighter, cleaner, fresher, more neutral. I was surprised. I also noted that over the next few hours, my coughing decreased significantly as long as I stayed in my office.When bed time came, I put the unit in my bedroom and turned it on full blast with the doors closed while I went to the kitchen to have a snack. At first, the bedroom registered 5. The unit quickly brought it down to 1. I noted that my coughing increased when I was in parts of the house that had not had the benefit of this device to clean the air.Returning to my bedroom after my snack, I noted that once again, there was a nice difference in how the air smelled in my bedroom compared to my kitchen.Normally it takes me a while to stop coughing enough to fall asleep when I got to bed each night, but last night while there was still coughing before sleep, it was markedly less, which my girlfriend commented on today. This morning, I woke up to the pleasant realization that my lungs did not feel irritated for the first time in a long time. I hadn't even realized how irritated my lungs were when I would usually awaken until it was gone.Moved the unit into my home office again, and turned it back on. It started at 5, and again rapidly cleaned the air until it was at 1. Then I began doing more experiments. I noted that when the AC kicks on, it goes from 1 to 2 or 3. When it turns off, the unit returns it to 1. When I open the door to my office, it goes to 2, and then back to 1 when I close it. When my cat walks into my office, it goes from 1 to 2 if I close the door after him, and stays there for as long as he is moving around. If I pet him, it goes to 3.Thinking this level of sensitivity was too good to be true, I decided to try further experiments. I closed my office door again, waited until it settled down, and sprayed some air freshener in my office. No change - it evaporated. Just as expected. Then I went down the hall and into my living room and lit a stick of natural compressed sandalwood powder incense. I returned to my office and closed the door. Within 2 minutes, this unit detected the incense in the air, rising to a 4-5-6 and then back to 3 when the AC turned off. The next AC cycle, it jumped into the teens, and then into the 20's, 30's, 40's as the smoke got going during the next cycle. When the count hit 45, it turned the ring green and stepped the fan up a notch.I found that I could watch the numbers go up when the AC was on, and down when it was off. It got up to around 86 at one point, and the ring sometime before that turned orange and stepped the speed up another notch. Now that the incense has burned out, it's dropping, with highs in the 50's, and lows i the 20's and cycling lower each time the AC kicks on again. It's been interesting to see it power up and down to match the particulates in the air.Build quality seems good, but the bottom can come off easier than I'd like. A couple times now I have tried to lift it only to find that it had un-screwed and the bottom and filter were not lifted with the rest of the unit. Easily fixed in a second or less, but if the bottom had a bit of "click into place", this would not happen when moving the unit.It is so quiet in sleep mode that last night when we went to bed, after I had it running on high for a few minutes while we had our snack before bed, that even three feet from it, my girlfriend could not tell if it was running and asked. This was with the AC not active. That's pretty darned quiet. It also was no issue for me to handle, and I am extremely sensitive to sound when I am trying to sleep.The top two levels of fan speed are relatively loud, with the highest speed being louder than my AC when it's kicked in. It is, however, the most smooth and beautiful white noise I have ever encountered, and I am an audio engineer.So far my experience with this is almost entirely good. Here;s what I don't like.1. The bottom unscrews too easily. No big deal, but irksome.2. The sensor didn't work when I got it until I updated the firmware, which forced me to download the app, sign up, and then give the app location permissions and blue tooth permissions. I also naturally had to sign it into my wifi network. I didn't want to use the app, or give the app these permissions. The app, however, will not run without them. Ostensibly, it uses location data to give you a report on local 2.5um particulate levels in your area (which it does), but I don't know what else it is being used for, and I don't much like having my location tracked by Google and every other company on earth these days.So far so good. It appears that particulates in my house are probably not as much of an issue as what those particulates are made of, and that I need to be more focused on reducing VOCs in the air in my house. But so far this unit has helped me breathe significantly better, and I'm very happy with how well it works.