This Old House has a really good breakdown on filtration and air volume and have a pretty clever DIY box fan approach using multiple filters. Still costs under

This Old House has a really good breakdown on filtration and air volume and have a pretty clever DIY box fan approach using multiple filters. Still costs under $100. The Wirecutter recommended Coway filter is $185 on Amazon. https://youtu.be/aw7fUMhNov8 https://youtu.be/aw7fUMhNov8