Medify MA-40 Air Purifier with True HEPA H13 Filter | 1,793 ft² Coverage in 1hr for Smoke, Wildfires, Odors, Pollen, Pets | Removal to 0.1 Microns | White, 1-Pack

I ordered two of these last spring. The first one was perfect and is serving me well in the room with 4 litter boxes. Whenever I scoop the boxes the machine, really does detect the activity and the extra dust in the air and amps up to a faster speed to clear the dust.Even though it’s in this one room, it has really helped the ground floor of my 2 story home become less dusty. And in most modes it is quiet enough that my cats actually like it and like to lie down in front of it. Strange, but I’m glad they like it. The feature sets are listed so I won’t go into those but everything works well. I don’t use any night mode, though, so I can’t speak to that. I just run it on auto and once in awhile use the ionizing cleaning.Much to my relief, there have been no weird burning plastic odors as reported with some other brands in the 8 or 9 months I’ve been running it.I did get a separate warranty registration in the mail because apparently one was omitted in the shipment sent to me. I found that interesting. I do wish I had registered within the prescribed period of time, but I’d put it aside while I dealt with other things and just let it go.The downside is that the replacement filter looks really expensive at $69. It’s an excellent quality though, and likely lasts longer than cheaper ones.Okay now here is where it gets weird for me. I decided I liked this filter so much that I would order one for our master bedroom, which is pretty large. And the unit arrived. But to my distress, it was put together weird. Seams were crooked and there was a lot of rattling noises inside. It didn’t look like it had been damaged in transit. It just apparently went through a very bad day on the assembly line. I turned it on and it ran. But the rattling noise was disconcerting.Basically it was horribly defective and not usable. And I was going to contact the sellers but then I noticed something odd in that apparently my order was still on its way. I was so confused. My name and address was on the box I had just received but the tracking number was different.And then my mother-in-law fell ill and we had to drop everything to take care of her. Meanwhile, as I’m on the way to take care of her, ANOTHER unit arrived to my house. I checked my Amazon account and only one second order is on record. And this third unit was the one. I have no idea why I was randomly sent a completely busted up unit. But I dragged this third one in and it sat in my foyer for a couple of weeks while I dealt with my family crisis.I would have assumed perhaps the sellers realized they made a mistake sending out a damaged unit and sent a good one, except there is no record with Amazon for that busted up one.Finally, I got a free moment from hospital vigils, so I pulled this third one out and externally it looked okay but internally it had something loose and rattled badly, too. So I set it aside intending to try and get all of this straightened out with the seller.But my mother-in-law got pneumonia and passed away. In dealing with the hospital vigils and her funeral, we didn’t have the time or the energy to deal with this. So all these months I’ve had two broken units in my bedroom. I just said the heck with it and ordered a Dyson for the bedroom during a massive sale.Meanwhile my original is serving us very well in the cat litter box room.I’m way past the time to register for warranties or get warranty service on the defunct units. I will just keep the broken extras for parts for the good one.So, basically it’s 5 stars for the absolutely fantastic working unit. But with a caution to do a quality control check when your air cleaner arrived and register your machines for warranties.

I'm very happy with this purifier. As was mentioned in other comments, I question the purifier's blue light which would indicate excellent quality air. Upon startup, after a minute of operation, the light always reverts to blue. I don't think the air quality had been horrible previously, but I'm not running the purifier because I thought that the air was of excellent quality to begin with.OdorsSince we don't have smoke in our home or any visible contaminants, odor is really the only result that I can judge for myself. I do not trust the light in this machine that stays on blue constantly. I was not expecting much of a difference in odor after researching purifiers. I had read that charcoal filters don't help much because in many purifiers the air is not in contact with it long enough to make a difference. It took a couple of days, but the difference in odor is amazing. There was initially a very distinct odor in the air. I can't detect any odor any more. While I have no way of proving that other contaminants in the air have been removed, I really have no reason to question it either.IonizationThis is just an extra feature of the unit that I will never use. There is question about how well this technology works and whether it causes more problems than it fixes. I cannot say how well this feature works. The best part about the ionizer is that when the purifier starts, the ionizer does not automatically start and I never have to use it.FiltersThey're a bit more expensive than some of the other models than I had looked at, but they are a higher level of HEPA that will filter the air better. Given the difference in quality, as long as I'm paying for filters to clean the air, I'll take the better ones. Filters are also very easy to install.Air quality indicatorApart from having to buy an ionization system that I didn't want, this is my only other problem with this machine. While running, it ALWAYS shows excellent air quality. There are only 3 levels of contamination indicated so even if I knew the light was working properly, it's only a broad indication about how bad the air might be. Judging by the only criteria available to me, odor, the purifier has made a big difference in our indoor air quality so I'm just ignoring the light.All in all, I'm very happy with this. While I don't trust the air quality indicator and I'd prefer not to have to buy the ionizer, these issues are not sufficient for me to lower the rating from 5 stars. It filters smaller particles than other purifiers on Amazon, the price is not significantly more for this capacity of purifier, and I am so much happier breathing the odor-free air that this purifier produces. I don't have reason to buy this purifier again (life-time warranty if I sign up within 30 days on their website and continue to change the filters as required by the warranty), but I am considering buying other purifiers from the same manufacturer for other, smaller, rooms of our house.