This design is intended for those who are willing to keep the litter box near a single-hung window with outer screening and no burglary concerns (i.e. probably not on the ground floor in a neighborhood like mine!). I will be following up this post with another version that couples to a bathroom exhaust vent.
This project is designed to cost less than $35 to make, and uses mostly common, recycled and/or re-purposed and cheap materials. It is also quite doable for someone with limited tools. Perfect for apartment dwellers!
* Hot glue gun and roughly 10 hot glue sticks
* Heavy duty poultry shears or tin snips
* Serrated bread knife
* Serrated tomato knife
* Electric drill
* Standard drill bit index (up to 1/2")
* Permanent marker
* Hooded plastic cat litter box with at least 7"x7" of flat surface on the back end
* 12V 120mm CPU fan (smaller sizes may also work...try recycling one from an old desktop computer). I used this one.
* 12V DC power adapter (500ma). I used this one.
* 2 x plastic food storage containers (25oz, 740ml - 6-3/4" x 6-3/4" x 2-1/4") with lids
* 2 x empty, de-labeled 28oz food cans (I used cans from crushed tomatoes) with both ends removed.
* approx. 10 hot glue sticks
* 5-25' (location dependent) of 4" dryer duct, aluminum or plastic
* electrical tape
* 2 x 16" long zip ties
* 2 small zip ties
* 8" x 36" rectangle of Owens-Corning Foamular(R) 250 or comparable (pink foundation insulation) or 3/4" plywood (if you have a jigsaw or sawzall).