Best air purifier for medium rooms

@lilianna There is always someone advertising the latest gadget, or the "game changer" and air purifiers are no exception. Keep in mind that what you want is an appliance that does what is says, with minimum fuss and maintenance, and can serve for years.
We live in 2 areas with frequent alerts for pollen, smoke, and other air quality issues. Our Central home system, attached to the furnace, has questionable effectiveness as a HEPA filter, soe we needed portables.
Here is how I selected our air purifiers, and they have turned out to be totally reliable and easy to maintain.
- I looked at Consumer Reports and a couple other independent sites to find well-rated units - not necessarily the top, if it wasn't widely available.
- I looked at the availability and cost of replacement filters online - from the manufacturer/ distributor, not Amazon. That meant national brands. This was from experience, my daughter had a great unit, but after 3 years, there were no replacement filters available.
- I looked at the availability for units sized for my spaces. We have one in the main living space and our bedroom. After some remodeling, we will be looking for another in our new space. In our tiny home and camper, we have units for the area.
- Since I needed several units, I wanted interchangeable filters, so I could buy in quantity.

What are your requirements for a HEPA filter?

I have a Levoit in bedroom.
It does have the energy star.
Do you think I made a good choice?
Just so many opinions out there on Everything!
I really like to read your post and also Linda Esposito.

I would add do NOT choose an air purifier that uses ozone -- it can irritate our lungs. Rather, choose an air purifier with an activated charcoal filter either as a "pre-filter" or as one of the multi-layers. Activated charcoal absorbs odors and ozone.
Also, many air purifiers screen out particles down to .3 microns. For us screening out down to .2 microns is better. They are readily available and will screen out most micobacteria (which causes our dreaded mac lung infections) and other air-born bacteria.

If you're prepared to take a deep dive this Reddit site has one of the best buying guides I've seen on air purifiers.
https://www.reddit.com/r/AirPurifiers/wiki/buying_guide/

@sheila7a The biggest thing is to choose a unit that covers your space, removes particulates, and keeps running. LeVoit units seem to have pretty good ratings, time will tell how long they last.

So yesterday we bought at Costco Shark Clearair max($350) It is a three step filtration system and its Sharks the new one. Worth looking into

I have 3 Coway air purifiers. I have a smokey odor from a restaurant
nearby. I have no idea if the purifiers are doing Rozanything. It has a button for Ionizer. Should I not be using that? I am thinking of hiring an industrial engineer to do a study. I have spent four years trying to get my building to solve the problem. It's much better but not solved. I'm on wait lists for several senior living facilities, but the lists are very long.

@rozie83
That's frustrating. An air purifier that removes VOCs (gases and vapors) will help a lot. They are pricey.
https://docs.google.com/spreadsheets/d/1trqIuex3-CiETPZUPYwhPKcizUEgShTTSnTP-jTkbvo/edit
https://docs.google.com/spreadsheets/d/1mKAOy-tx3ocIX1XCUoNFoiVV1M8dhn3nHC3hl81Kn-w/edit