I am modifying my darkroom. The complete work area is not bigger than 2,10m x 1,80m. I have bought a Nova Washmaster-Eco Archival Print Washer recently, so, by the time the darkroom will be finished, I would be able to print FB paper as big as 12x16, and even 20x16 washing manually. I am going to incorporate a sign (1,75m x 0,65m x 0,20m) that I am making right now and I will also put an Extractor Hood just above it. I have taken this idea: http://www.eepjon.com/venthoods.html. I will use galvanized ducts to take the air out, and an appropriate light tight louver that will be located in the upper side of the door. (http://www.adorama.com/searchsite/default.aspx?searchinfo=louver, for example). The question is: How many meters cubic per hour (M3/h) (or fpm, if you prefer) should the fan be able to move? In other words, which fan do you recommend me to buy? By the way, I would like to get some different ideas about how I could ventilate my darkroom, which kind of vent hood, fan, etc. I also appreciate any idea about what I should add to my project. This is the time to design, since nothing has been done yet. I am annexing a layout of my future darkroom. Thanks, Henry.