Can someone recommend me a decent air purifier?

If looks dont matter, I'll recommend the same thing I always do when people want an air purifier.

Look into making a Corsi Rosenthal Box. They're surprisingly effective, and dirt cheap.

It's not just about aesthetics. That DIY box will be loud as hell.
- As mentioned in the article these can be quieter than a retail unit. The large fans move a lot of air and the large filter area means it's easier to pull that air through; both combined mean a lower fan speed is needed for a given throughput.
- That'll help me sleep
- I have one. It's not that loud. Even when you are standing right next to it it is easy to have a normal volume conversation.
This looks really cost affordable and efficient, but I’m not sure my wife will go for the DIY aesthetic.
Beat me to it. I've just been taping high quality filters to the back of my box fan, not as good, but helps in a pinch.
Alternatively, a single Merv-13 filter that's 4 or 5" in depth (20x20x5) taped to the box fan works just as well in a smaller footprint, and still allows you to direct the airflow at someone.
Thanks for the link. Very neat
Does anyone know where I could find some 20-in wide charcoal filter cloth sponge material?

I would like to be able to have my filter reduce odor in the home as well but I can't seem to find anything other than little 4-in strips.
- Is 24inch * 100 feet enough?
  
  https://duraflowindustries.com/product/371/Duraflow-Filtration-Activated-Carbon-Filter-Material-Bulk-Roll---24-1/2
  
  Edit: They have the foam as well, but it appears to only help against dust particles, not smell. https://duraflowindustries.com/product/381/Duraflow-Filtration-Air-Filter-Foam-Roll-Media-24-x-25-x-6.35mm-(1/4)

Whatever you buy, make sure to remove the plastic wrapper of the filter before use.

Ask me how I know

Did it melt or something?
- no, it just won't suck air in and result in a filter that does basically nothing

Don’t waste your money on anything that doesn’t have a HEPA filter, that’s the golden standard.

Make sure you’re doing a bit of math on how much air purifying power you need, what works for a 100 sq ft room with an 8 ft ceiling is going to be insufficient in a 400 sq ft room with a 10 ft ceiling.

Fortunately, someone has made a nice calculator for that here.

Winix and Honeywell have been good brands in my experience.

HEPA filters may not be necessary - it seems that homemade air purifiers with standard filters can outperform them in clean air delivery rate, arguably the most important factor for a purifier. The air may not be as clean with each pass through it, but it'll move much more air.
+1 for Winix. I’ve had several of the 5500-2 units for 2-3 years now. They do a good job and I appreciate that they have HEPA + charcoal filters so eliminates more than just particulates. My main complaint is that the lights don’t fully turn off at night so I always have to cover them with something (usually a T-shirt). Otherwise I really like them.
- get yourself a roll of black electrical tape and cover up all the LEDs and brand logos in your place.

20" box fan + 20" furnace filter. Both are pretty standard sizes. Add duct tape as required.

Here's a video on how to do this: https://youtu.be/EUHVo54tXz0
I did this this year for wildfire smoke, and it works great. Having said that, it is not quiet and the way I was using it was to run it at full blast for an hour, then leave it off for most the day.

If you wanted an always-on solution, I think I'd actually suggest a commercial air purifier.
- You could also add in an inexpensive wi-fi smart plug and set up a schedule where it would turn on and run for 15 minutes every 2 hours or so.

I've been happy with Coway.

Got a Coway too and a like it. Airmega 300

When the air turned orange from the Canadian wildfires last year, I had massive, massive headaches from the smoke. On the recommendation of Wirecutter, I bought a Coway, and my headaches cleared up.

I've been very happy with it. The low and medium settings are quiet, while the high setting is a bit noisy for me. When the wildfires were running, I had it on low or medium all the time and it was fine. Since then, I mostly have it on Eco mode, where it samples the air periodically and kicks on at whatever speed it thinks is necessary. Mostly it just quietly pops on at low speed for dust or pollen or whatever, and I rarely notice that it's done so. It always kicks in at high speed for a few minutes after I've changed the cat's litter, and once it noticed that the bread was starting to burn in the oven before we did, lol.

Anyway, I got a Coway based on Wirecutter's recommendation, and I've been very happy with it.

Edit: I got the 200m, which covers like 1700 square feet.

Yo, looks like you're into gaming.
Someone made an air purifier similar to a gaming PC chassis. Using a special metal case and with space for filters. About as good performance as the box fan/filter abomination but with easier replaceability.
Pretty sure you can find a place for rgb fans too. https://housefresh.com/nukit-tempest-review/

On mobile so won't grab all the links, but I've done a lot of research into air purifiers and can echo what most people said

Most air purifiers over 50$ are as good as the ones that sell for 150$+
I personally buy Winix
An air purifier can clean a room in 1-3 hours, but since I'm paranoid I keep mine running 24/7
Don't buy anything over 100$, it's not worth it (if you want super clean rooms, buy one for each side of your house)
Clean your air purifier (just wash the filter) every month or two (there's a lot of dust it traps)
Enjoy the investment, air purifiers are great!

I've got two Coway Airmega AP-1512HH air purifiers and they've helped a lot during the bushfires in California. They're on sale right now for $140 each during the Prime Day sales.

I got a 20-in box fan and four 20x20x2 air filters.

Tape the air filters together into a square and then tape the box fan on to one of the open sides.

Said it so the box fan is facing upward, plug in and turn on. You have a whole house air filter for like $50 or less that will do as good of a job if not better than pretty much any other device on the market.

When the air filters start to turn a dingy color, replace them for 20ish dollars. Fan should be good for several years.

One important metric: m³ / (hour*$), so how much it can filter for how much money
Also the volume on the setting that gives the filtration power needed. Often it is best to get a bigger one, run on middle or low level, especially for office or bedroom.
How much m³ / hour overall? When it is against dust, allergens, pm2.5 etc., filtering your room volume once per hour is decent. To protect from viral infections, e. g. at a dentist or doctor, 6x the volume of the room is ideal. For private use, it's nice when it can do once per hour on a lower setting, and for occasional parties 6x of that on a high, loud setting to avoid spread of viruses.

Pretty good for your money is the Corsi-Rosenthal Box mentioned already. As for things that don't require assembly, Trotec beats all prices in Germany, e. g. the 250E or 350E: https://de.trotec.com/shop/design-luftreiniger-airgoclean-250-e.html That would provide more than you need for typical home use already. For a single room such as your bedroom, you can get something really decent for less than $250.

The ones that are below HEPA standard are not as bad as somebody mentioned, imo. Against many things, such as dust or allergens, they should be fine. I'm buying only HEPA filters myself, though; doesn't really save much otherwise.

I like our Honeywell Insight. Looks OK, is quiet enough and most importantly: Has readily available generic HEPA filters. I use it for fire season, it makes a noticeable difference to me re: wildfire smoke in my house.

I’ve been using a blueair one for a couple years

What are you hoping to filter with it? I have a general purpose Honeywell Insight, it works well enough for my allergies and pet dander in my apartment. I think I paid something like $200 for the unit 3 years ago, but filters are $85 a year for it - pricey but they're widely available.

I guess that's something I should be more forward with. I don't really know what I am trying to filter out. I feel like my apartment can feel stuffy at times and agitate my sinuses but that may have to do with my AC unit pumping largely unfiltered air from the a busy downtown area into my unit
- I’d recommend you also get a cheap (likely $5-10) hygrometer to check the humidity levels inside, getting it to stay between 30% and 50% is best for air quality according to the EPA. If it’s above or below that you’d want to get a dehumidifier or a humidifier.

Levoit has decent ones for under 100$ idk how big your apartment is but theyre typically meant for a single room. So maybe get 2 and put 1 in the living room and 1 in bedroom?

I'm really happy with the one from IKEA, the bigger rectangular one. I've had it over a year. Not the prettiest, but if you don't dislike it it's alright

Depending on your needs, if you want the most effective filtering for the price (though at the cost of noise) you could make your own https://en.wikipedia.org/wiki/Corsi–Rosenthal_Box . I built one and found it to be great, but I did end up buying a commercial one through Costco years later.