Ventilation System for IKEA Billy bookcase

I added this ventilation system to my Billy bookcase so that I could put a Morliden door on it and enclose my network gear without overheating it. I used a 5V fan so that it could be powered by a USB charger in the cabinet. The fan speed is constant and adjustable controlled by a PWM circuit. It all prints on a 200mm*200mm printer diagonally. The thermal performance is pretty good. The case temperature on the router in the top compartment dropped by about 25F.

The blower/duct gap is sealed with clear silicone. Tape would work as well.

*5V 120mmx120mmx32mm blower: https://smile.amazon.com/gp/product/B07PFNDYBZ/
*Motor speed controller: https://smile.amazon.com/gp/product/B00RYKR83Q/
*(39) #8x3/8" round head sheet metal screws or similar
*(4) M5 hex head cap screws and nuts for the adjustable feet
*Foam weatherstripping to seal up the panel gaps when the door is closed