I sometimes work in the same room as my 3L, and got into the habit of covering it with the original cardboard box lid when printing, to help contain the fumes. Although only ever intended to be a temporary solution, I recently upgraded to a simple negative-pressure setup:
Not fancy, but it’s working great. The air filter is an IQAir GC MultiGas, which does general room air cleaning when not on printing duty. The crude homemade adapter easily pops on/off without tools (although they have an off-the-shelf duct adapter available for more permanent installations).
The box handles were 3D printed of course, and have matching inner plates matching the contour of the cardboard overlaps: