[DragonStrength]

The biggest effect is in homes without any sort of central air system, which would usually include various levels of filters up to HEPA and UV systems at this point. During the worst of fire season in the Bay Area though, a single Coway HEPA filter, basically a box fan with a HEPA filter strapped to it, kept my apartment in the "safe" range for AQI. Just stepping out my apt front door into the hallway I'd be hit with the heavy stench of smoke.

Truly remarkable how well they work, but whether you need one or not depends on whether you have allergens/pollution as an issue in your home. You can purchase an air quality monitor (I have a Temtop M10) or check online measurements of AQI, pollen, etc. for your area. If you have an issue, they work, but not everyone has an issue.

[techwiz137]

Okay so I bought a cheap-ish Air Purifier, now because the brand is...I think it's Chinese(Rohnsonn), I can't determine if it really does anything, if these filters do anything at all to improve my air quality and if the UV light is even strong enough to kill germs. Is there a way to verify it's effectiveness?

[DragonStrength]

I'd look at what the purifier claims to eliminate and find a quality monitor that will give you a reading. Most are portable, so you can compare to outdoor values directly. You're going to need some baseline to compare to though. If you have an AQI in the safe range already in your home, you'd have to contrive some actual experiments or find someone who already has.

I'll say I'm pretty distrustful of anything but filters personally. My mom purchased a purifier at one point which claimed to use UV light to purify but had no fan to actually pull air through the light, so obviously, it wasn't doing anything.