Build a Do-It-Yourself Air Purifier for About $40

If you are worried about particulate, you can build one of these: [VIDEO] I built one for my room because my previous tenants had cats, which I'm allergic to. Even after steamcleaning our apartment I was chronically congested. Built one of those purifiers and a few days later most of my symptoms are gone. It's been about a month now and the filter is noticeably soiled.

Here's a video from the University of Michigan showing just how effective these cheap DIY air filters can be: [VIDEO]

If this is because of high PM2.5 concentration (due to wildfires or otherwise), I suggest building a DIY air filter, such as the one in the video here: [VIDEO] When the Air Quality Index shot up to ~150 in my area (you want to keep it below 100, preferably below 50), I went to Home Depot and bought box fans and furnace filters and built my own. You can check the air quality in your area on this site: [LINK]

The University of Michigan made an instructional video showing how you can easily make an air purifier out of a box fan and a HEPA-rated furnace filter for $25: [VIDEO] It won't be as good as a purpose-built machine, but it will be far better than nothing at all. TheWirecutter found it reduced particulate matter in a room by 87%, if you do it right. They also make clear important caveats about this method -- in short, this works in a pinch, but probably should not be used in place of a purpose-built filter if you want one for year-round use. [LINK]

Yeah, same thought. Something like the Coway air filter ( [LINK] ) regularly sells for under $200, and it is going to be much quieter than this option. It also has been tested fairly extensively from what I've seen, it's EnergyStar approved, etc, and it has a built in sensor. It doesn't look too bad either. But I understand the point, especially in times when you can't find a purifier. Also, good video on all this: [VIDEO]

But I thought it has been shown putting simple furnace filter on a fan is good enough. [VIDEO] Are you talking about other filters to filter the larger particles, and carbon filters? Because aliexpress sell them too.

I know a certain framework creator that will be all over this - and has been vocal on twitter about it. I went looking, this seems like a pretty good air quality monitor: [LINK] (~$400) There are cheaper ones too; but do your research, as accuracy (and ideas about what constitutes accurate) can vary from manuf. to manuf. [LINK] also apparently, a box fan + filter ain't so bad. [VIDEO]

[VIDEO] you just put a fan filter on the back, you can increase the amount of filters to not hurt the fan motor as much by making a triangle config or fan on top of 4 filters in a cube. fans are for air throughput not static pressure so real air purifiers have squirrel cage blowers