The BentoBox filter for a Bambu Lab X1C or P1P is great for filtering fumes, but I was worried about carbon dust from the activated carbon pellets being blown into the printer, so I moved the 80x40x15 HEPA filter to the bottom of the carbon box. To ensure a snug fit, I made this shroud for the HEPA filter. Print 2 of them and clip them together inside the carbon box, then put the HEPA filter into it. It's a tight fit so that there's no air leaks and it all stays in place. Now you can pour in the activated carbon pellets and be confident that there won't be any carbon dust spread through your printer when the filter's fans are running.
Cheap HEPA filters are available on Aliexpress - search for “iLife Hepa Filter V5”
The author marked this model as their own original creation.