A while back I modified the enclosure, I have for my XL to have 80mm fans attached so I can keep the doors closed and not get too hot.
I decided to add a filter box which I filled with activated carbon to get rid of any VOC some materials produce when printing.
There is now a slider to close the vent which redirects the airflow back into the chamber.
With the amount of activated carbon and fans I used the airflow was pretty weak but good enough for my uses.
Each of the parts that have a mesh attached uses some slicer trickery to generate the mesh using infill, so if you don't like the size of the mesh or the style of infill there you can easily change it :).
You will also need an assortment of m3 screws and m3 heat-set inserts.
The author remixed this model.
I added in holes to the vent panel I designed to accommodate the new filter box.