This is the filter I bought. it handles 2 printers. It is in a small closet at the bottom of the stairs (no outside ducting). Probably 6ft x 5ft x 4ft. right now the filter unit is $40 off ( use coupon on amazon site)

https://www.amazon.com/gp/product/B07T3V8NK6/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

I also have a floor space heater and external thermostat that keeps it at a steady 75 degrees

https://www.amazon.com/gp/product/B08KGF1MPJ/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

https://www.amazon.com/gp/product/B01I15S6OM/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1