I ended up purchasing a Lasko Air Flex[1]. It fits standard HVAC filters. It doubles as a white noise machine for me, it is quite loud. This review[2] indicates it works well but a bit power hungry, and it definitely gathered a visible amount of dust over a 1 year period.
[1] https://lasko.com/products/lasko-air-flex-2-in-1-20-inch-box...