Uses a 120mm case fan and activated charcoal filters to lessen some of the smell associated with printing in ABS plastic. Also works exceedingly well as a solder fume extractor.
Included in the base is a hole for mounting a power toggle switch, a hole for a 12VDC power jack, an enclosed area for hiding cables. In the left leg of the device, there is a recess for hiding the fan cable, and retention clips to keep it hidden. The legs include nut-traps for 10-24 screws (cannot remember the length) for attaching the base of the device, and the rest can be assembled with long 10-24 screws or with zip ties (what I used).
A relatively powerful fan is needed to pull air through the 4 activated charcoal filters that I used, though fewer filters can be used if necessary. The fan should be mounted to the back of the device, so that air is pulled through the filters.
The fan grille used for this Thing is a customized version of http://www.thingiverse.com/thing:71961.