I am currently under construction on my "in house" darkroom. I've partitioned off a back room to include no windows, have 8' x 11' and 99" height so my Durst L1200 sites fine on a 30" high table. I plan on putting in a laundry type deep sink along a wall that falls between two small corner closets which will contain print dry (fiberglass screens) racks, shelves for chemical storage, film drying,etc. I think I will build a box shelf above sink about 5' high that will contain two bathroom exhaust fans and vent them (ea.) straight up into attic...shelf can also be used as, well, a shelf! Q#1) Is that acceptable, or should they vent all the way to the outside? I will most likely go vertical with the trays next to sink as I will be limited to 6 feet of width in that space. On the opposite wall from sink, where my 6' counter will be, I am thinking a set of 3 or 4 2.5 inch tubes, elbowed twice (in the wall) to have airflow into the room. This incoming will be from the house-not outdoors and they will be set low from one foot to about three from floor. Q#2) Is this enough? Too much? Or other suggestions. I am trying to rough this in while trying to keep from messing up the house too much. It is also my own first darkroom. No more stepford labs for me. There will be six dual electric outlets, which someone will say "not enough", but that be the way it is... I also have finished wood floors-vintage 1938 that I refinished, so I may lay down something overall...any thoughts? Your experience is appreciated-thanks.