Please read the AutoModerator comment. Air purifiers aren't good at reducing *visible* dust as it's larger and heavier than "invisible" pollutants like PM10 and PM2.5. The same goes for pet hair.
Sans is terrible. Shark is mediocre. Avoid both.
Coway is generally one of the highest quality consumer-grade brands. Winix is good, more mid-grade.
Blueair has an always-on ionizer. Some people want to avoid this because of possible health effects associated with ionizers or changes in gaseous air chemistry.
Per the AHAM 2/3 rule, a space 600-800 sq. ft. needs minimum Clean Air Delivery Rates (CADRs) of 400 CFM - 534 CFM.
Unfortunately your budget doesn't support a single large or multiple conventional HEPA purifiers. (An example that meets CADRs would be the [Coway Airmega ProX](https://cowaymega.com/products/airmega-prox).)
If you still want a conventional HEPA purifier, go with the [Winix C909 at Costco](https://www.costco.com/p/-/winix-c909-4-stage-air-purifier-with-wi-fi-plasmawave-technology/100842491). It's a bit of an energy hog (95 W) and somewhat loud on the highest setting called "Turbo" (60 dBA per the Decibel X Android app), but it's good value for money. The C909 has PlasmaWave, a bipolar ionizer. You may want to keep this off if you have pet birds.
Another option may be the [AirFanta 3Pro](https://air-fanta.com/products/airfanta-3pro). It uses Efficient Particulate Air (EPA) E11 filters, which is two filter classes below HEPA H13. Top composite CADR is 413 for the CARB Edition. Price is $159.99.
Keep in mind CADRs listed by purifiers apply to the highest airflow speed/setting only. Lower settings have lower CADRs which reduces cleaning effectiveness.
I think I'm parsing your comment here correctly, but... don't buy Shark.
It's a lousy brand with very misleading marketing—e.g., "NeverChange" filters. They don't publish Clean Air Delivery Rates (needed to size a purifier for wildfire smoke particulates). It also has a tiny amount of activated carbon so it's useless for VOCs or other gases.
We've seen multiple issues with Shark's air quality display malfunctioning on r/AirPurifiers.
You need many pounds of activated carbon or other sorbent media for wildfire smoke gases, VOCs, or odors. And even then, plain/non-chemically treated activated carbon doesn't have high removal efficiencies for all gaseous species.
I just got an inexpensive Shark max never Change
and am surprised how much of a difference it makes, also to stale air. I only suffer from minor allergies, for serious cases i would definitely upgrade to a better model. But do get one.
Really like our Shark Never Change. The big hepa filter lasts multiple years due to the washable pre-filters. The thing just sits on “auto” 24/7 and has gotten us through 2 wildfire seasons with great results.
I bought the shark never change as my first purifier just recently and I feel the difference with my allergies. The 5 year filter change really attracted me but after reading here a little more I might need to change it more frequently.
I also tried the blue air for my office but didn't like it, I didn't feel any difference and it was noisy, I returned it and got the smaller shark never change .
Top Air Purifiers on Reddit
1
Coway
Airmega AP-1512HH Mighty
87% positive of 126 users
Durable, effective for allergens/odors, but loud on high.
sissasassafrastic
