Darkroom: Ventilation

Proper ventilation is essential in a darkroom. Chemicals, especially fixer (hypo) and acetic acid (stop bath), give off strong fumes that can be disturbing, can aggravate respiratory ailments and are extremely unhealthy in a non-ventilated space. Air conditioning is a logical solution, but not always possible or viable. The complete darkroom should have, at the very least, a fan and a louvered intake vent to promote air circulation. A fan, although not a cooling unit, should be placed so that it exhausts the air from one end of the darkroom (ideally via a hood that hovers above the chemical trays in the sink) while a louver should be placed in an area opposite the fan so that fresh air is pulled into the darkroom, across and then out through the fan, taking fumes with it. Louvers are nothing more than light-tight cutouts that mount in a door or wall. Darkroom fans are designed to run quietly with minimal vibration.

It is important to remember that if the fan is going to stick out of a window, the casing must be weather resistant. There are fans that are rated only for room-to-room use.

The size of the fan and louver are determined by the size of the room and how many cubic feet of air the fan can move every few minutes. For example, if your darkroom is 12 x 12', there are fan/louver combinations that can effect a complete change of air in that space every three minutes. A B&H Sales Associate can help you determine the appropriate size for both. Be sure to have the length, width and height measurements of your darkroom available.