I’ve been very impressed with the Coway Airmega 400 I bought last year. It’s able to clean approximately 1500 sq feet, though I can’t vouch for that. I usually keep it in my master suite (approximately 600 sq feet) but bring it out to the large double story family room/kitchen area at times. I have a doggo staying temporarily and my human roommates are fabulous cooks and it cleans the wet doggie smell and the food. I vacuum the removable filters about every two weeks. There’s an icon that lets you know. The “permanent” filters will probably last a total of 10 months based on past use. I run at full speed all day and turn down to low at night. Super easy. It’s very quiet. It’s smart phone capable but, alas, I’m not 🤣. It helped with the moldy smell in my home, (I’m renting).

We have 5 cats and 6 litter boxes (in 3 different locations). We use two small non-name brand purifiers near two litter box stations. They both collect cat hair on the outside of the purifers where they suck in air. Both the filters get full of hair and litter dust. I shake them out and vacuum in between filter changes. Both those purifiers we run on low due to their noise - I don't want to scare the cats away from the area. I don't feel like they help a lot with odor, but I probably need to run them full speed for that.

Recently I bought two larger Winix purifiers on sale at Costco. One is set up in our living room and the other in our lower level. They are very quiet and the filters are supposed to last 6 months or so. They are still too new to comment much on their effectiveness but they get good reviews by other Costco customers.

I'm happy with my Germ Guardian air purifiers, but they don't do anything for odors. I don't think air purifiers are designed for that.

I have one of the Coway ones for fire season. It is quiet and nifty looking. It should help a lot, but it's more for large particles like viruses and dust.

Many of these air filters are not rated for food smells (or poop smells) which are physically smaller than the particulates for which they're designed, but I think they still help. Some have carbon filters which help with smells. (Methane molecules, for example, are way smaller than a virus...)

For litter boxes, I might upgrade to the ones designed for smaller stuff because, well, you know. Cat poop. :) On the other hand, the filters for those will cost more and probably fill up rapidly in a catbathroom. (I don't know--maybe they have prefilters for big chunks? I haven't investigated those but I wouldn't be surprised.)

If you're brave, there's a subreddit on air filters and you can learn more than you want to about what types of HEPA, etc., filters do what.

We have 2 cats, 2 litter boxes. We have a whole house Broan hepa filter air purifier. We think the air purifier does a GREAT job with smells! We've been sanding the wood windowsills & spraying lacquer on them. Takes away the lacquer smell in a couple of hours. Altho ours is not portable...I think a portable unit is a great idea!

Thank you all for your comments.. i will make a decision on your choices. thank heaven you gave me your best thoughts.

The Blueair Blue Pure 211+ earned a recommended score in CR's tests. It's reasonably priced and owners like it. Also at Best Buy.

I don't have a recommendation for air purifiers, but we have 2 cats and got a Litter Robot. I had been scooping litter multiple times/day, and now I change the box 2x/week. My husband built a cabinet for the robot (definitely a proud woodworking moment for him!! this is the nicest thing he's ever made... haha) -- but it's very similar to the one that Litter Robot sells, so there are non-DIY options. Anyways -- this is not what you would call a compact solution, but I don't smell anything anymore. ;)

I'm with Emily. We have 6 cats and 2 Litter Robots. They scoop EVERY time a cat uses one of them. We smell nothing offensive.

I bought a Jafanda Air Purifier when we were getting the smoke from the wildfires and the pollen from one of our trees was everywhere. I bought one for a 1190 square foot room. When I plugged it in the air quality number was over 100 and within a few minutes the air quality was down to 2 and we really could tell the difference. I don't have cats but if you burn something while cooking the air is cleaned quickly. I notice also that one of my family members allergies are so much better. After having the sewer cleaned out a few weeks ago my house smelled terrible, the air purifier didn't seem to touch it but I had ordered some bamboo charcoal bags on Amazon and hung 5 of them in the basement and they absorbed the odour. They are reusable, just put them in the sun for an hour or two.

Thank you all for answering. i'm amazed at the answers for a litter robot.

on a sad note my two eldest cats died in the same week after my question. one of old age and the other of a hyper thyroid. i have been looking for rob333 updates on Murphy and might have suggested tests for thyroid problems. kidney tests were done too. my kitty barely survived the nervous ride there, and during the tests the docs had a hard time holding her down. i took her home and she died in my arms. with one calico at home left i fostered kittens right away. our shelter is helping shelters in West Virginia and the south and as far as India and my town supports fostering.

love you all for continuing this conversation.

@Maggie200 Oh no, I'm so sorry. :( :(

Someone, I think on this forum, recommended to me about a year ago that I try a stainless steel litter box. I didn't even know such a thing existed--changed my life. It's nearly completely odor proof. The plastic boxes just hold the odor even when they're cleaned regularly. Now I never smell an odor in the small room where the box is except when it's just been used.

Oh, maggie, I’m sorry to here this. 😢

Maggie, I am so sorry for your loss. Bless you for fostering.

Maggie so sorry for your loss! I too commend you for stepping up right away and fostering kitties. All the best and hugs to you.

Maggie, I am so sorry about your loss. Losing two cats so closely is doubly sad. I lost three pets, one young cat, and two very old dogs in six weeks in the spring and it's traumatic for sure. I have no advice to offer but we keep three litterboxes all in the basement. They are cleaned every day and there is zero smell in the house.

What an air purifier will do depends on its particulate rating. Some will just remove dust others will remove very small particulates like the smoke from wildfires. Do your research and also investigate the cost of filters; some replacement filters are quite expensive. I have a Levoit, which I run in my living room because I have a woodstove and I’m concerned about the particulate smoke. It works very well. The filters cost about $40 to replace (here in Canada), and get replaced every six months. In between , they’re vacuumed about every week or two.