This is a simple set up for a stinky problem. (it works better then it looks, i just quickly set it up to see if it works)
the motion switch I used turns on for 5 minutes but can be set for 10 or 30.
I used the following:
1 cardboard box big enough for the litter box and for the cats to move in
1 small hair drier (2 dollars from a second hand store, you can use a vacuum but it make a lot more noise)
1 motion activated power switch (35 dollars)
small extension cord
laundry drier sheet
Step 1: Hair Drier Set Up
fold laundry drier sheet and cover the end that blows, use rubber band to hold in place.
plug in to see if the hair drier is working on cool and air is flowing through the drier sheet
(i had to remove the hair drier handle so it would fit better)
Step 2: The Cardboard Box
I also made the entrance big enough for the litter box to slide in and out, for an easy cleaning.
cut two small holes in the top.
one hole is for the hair drier intake and size accordingly
the other is for the motion senor and size accordingly
Step 3: Assemble
plug the hair drier into the motion switch and use extension cord to plug in motion switch.
make sure to position the motion switch so the cats will walk under it.
I set my switch to come on for 5 minutes when the cats use it.
(I also taped the small holes and cracks on the top of the box)
(I had to place the drier on its side because, its a side intake)
(after wards, I also made a small air expansion box for the end of the drier and put baking soda to help with odor control)
Step 4: Conclusion
soon as your cat walks in the switch activates and starts the hair drier and filters the air through the laundry sheet.
the cats took a little while to get used to the noise from the hair drier.
it works great and can be made to look great as well.
I'm no longer choking when the cats use the litter box.