The Sh*tty kitty shed™ I made from scrapes today!

Bless them but my young cats are horrible at covering their poops and I was sick of being embarrassed of the smell so I made this fume hood out of planks from a downed fence and an old heater fan that I de-soldered so its just a fan as well as an old gym mat. Total cost was only $30 for the vent tubing!
I'm sure there are better options but I'm a do something about it now kinda guy and just needed a small fan to create a tiny amount of negative airflow to get rid of the majority of the stink lol. What do you guys think? any advice to improve it?