Air Blast Mini - MKII

I would say thats super ineffective, just get a smart air blash mini per room and change filter every year.

I wouldn't say a purifier isn't doing anything if it's on low speed. I understand in most cases you are correct ..or at least for most casuals....but for my Smart air blast mini, I can run it on speed 1 24/7 in my living area since I don't need 6ACH for pollen. All I'm saying is, it depends on the use case.

Oops sorry I misread where you said budget was $250! I'll leave this here just in case it's helpful for someone else down the line. Looked up the C545. Claims it cleans 436 ftsq every 15 minutes (4x per hour). That would be on high speed. There are a few other purifiers that have better cleaning performance and can be quiet. When considering my recent purchase, I looked at Smart Air Mini Blast which can be run on lower speeds and still has a high CADR/CFM. I didn't like the short warranty and ongoing energy and filter costs were on the high end. Same applies to Coway Air Mega Pro x, although Coway offers 3 yr warranty as opposed to Smart Air which is only 1 year. Both of those are good units that can be run quietly on lower speeds (so I"m told). I chose to get Alen 75i, as it is quiet enough to run on highest speed which Alen claims is 375 CFM. That means it can "potentially" clean 703 sqft 4 times per hour. It is recommended though to have more than one unit if you need to cover more than a 300 sqft room/area. Retail $749-799, but have seen as low as $650 on Alen website and Lowes carries the Version 1, which is missing a few of the auto/app features and slightly less coverage (1200 vs 1400 sqft every 30 min according to Alen rep) for $523 with the basic filter (no carbon). Have two and these work well for me as I like the aesthetics and the ease of controls and can run at any speed without an annoying noise level. A bit bulky, 27x11x 18, but you can place against a wall or a couch/table because it takes in air from the sides.

I have had the Smart Air Blast Mini since 2022 and it’s been excellent. Runs daily, almost around the clock. My home set up it basically it and several CR boxes. Air quality is great and we’ve had no transmissions in the home as far as I can tell.

I have a smart air blast mini in my living room and an iqair in my bedroom, but on your budget I would replace the iqair with a coway or even do 2 smart blast minis if you have the space