**Given the emissions that 3d printing gives off (ABS = styrene and other chemicals, PLA give some off, etc), what options are there to filter the air in the enclosure other than venting the air out of a window?**

More information on the chemicals 3d printing emit:

 - http://built-envi.com/portfolio/ultrafine-particle-emissions-from-3d-printers/

It looks like activated carbon filters would be a strong performer for ABS (styrene) and PLA (lactide):

 - https://www.sentryair.com/activated-carbon-filter.htm

**Are there better filtering materials or processes for filtering the air in an enclosure?**

Here's an example filter setup:

 - This fan mount: https://www.thingiverse.com/thing:780001
 - 60mm fans and this filter: https://www.amazon.com/gp/product/B00XNI5SY4
 - And sandwich the filter on the fan using this fan grill: https://www.thingiverse.com/thing:11906