Here's a picture of my hillbilly enclosure. It's a cheap clear plastic tub that fits all the components of my reprap. I used a dremel to cut a 100mm hole in the top and holes to mount the fan. I used a Scythe ULTRA KAZE 120mm fan that is powered by a battery charger at 12v. I used wood screws to mount the fan to the plastic container and as an added bonus, I also used the screws to secure 4 layers of carbon filter to the fan. I can place nail polish directly under the filter and smell absolutely nothing on the other side.
One thing that I expected but didn't expect to be very bad was the static electricity that the container stored. So I decided to glue aluminum foil panels to every side of the container which are all interconnected and grounded out. So far no more static electricity.
What do you think? Practical, safe enough?