Quote Originally Posted by Zandor
Make one your self. It's just a wood box with a fart fan, 3 to 5 furnace filters, one return grill and some plywood. Use active charcoal from the local fish store 5 pounds each layer. Tap all the layers of filters together at the ends so all the air that goes in goes through and out the other end. A little gap in the top will equalize the pressure and make better use of the full size filter screen. Another gap under the filter and between the fart fan and filter will also increase the efficiency of the charcoal scrubber.

You can vent it outside or just return the clean air back into the room depending on your need.

It's that easy and it does work
What do you mean by fart fan? What kind of fan should be used and how powerful?