The freezer space sounds like it would be perfect for the fans and heat source. Take the door off the freezer part letting it be open into the fridge part. Your humidity pans can go at the very bottom of the fridge and 2 turners in between. Any thoughts on the type of thermostat you want to use?
My tablet is just about dead. I will recharge and sleep and on the issue and hopefully have some sketches of my ideas in the morning. Good night all.