Question about darkroom ventilation

[M Carter]

Well at least you won't have any sinus problems for a while

Sh*t, I didn't have sinuses for a while!

 

[Luis-F-S]

Im building a new darkroom in my house and am not sure about the ventilation. I have a simple bathroom fan that is more than enough for my smallish 11'x11' darkroom. My question is about the louver I will need to install in a wall opposite of the exhaust fan.

Do I need to purchase a special light tight louver such as this? Or is there an easy way to make a simple household louver air tight?

I have two of the 12 x 12 light tight louvers on the "inside" wall above and below the intake which is opposite the louvers on the "outside" surface of the same wall. I have an A/C filtered register to keep dust out of the darkroom. I have two louvered fans directly over the sink on the opposite wall as the intake. Ideally, I would have the fans on the back wall at the sink level but that was not possible due to space constrains. I've included some photos below. L


Filtered Register on the outside of the wall

Intake registers on the inside of the wall above and below the filtered register, to the left of the enlarger.

Exhaust louvered fans 400 cfm each over the sink with a speed control to dial down as required. Fans are on a fur down with an exhaust pipe to the outside of the building.