How vital is a dark room extractor fan?

andysig · Feb 1, 2011

I'm in the long, slow process of setting up a darkroom and read in a book that a light-tight extractor fan is a good idea in a darkroom because of potential danger from chemicals etc. How true is that for B & W dev and printing and E6 slide and subsequent ilfochromes?

I looked around on the net and found one for sale on the Nova website but they wanted silly money for it. If they are necessary, can anybody recommend a decent model (ideally available in UK/Europe)?

Mainecoonmaniac · Feb 1, 2011

Your health depends on it. Don't save the money . You might be able to convert an ordinary bath fan to a darkroom fan without much money.

jeffreyg · Feb 1, 2011

When choosing a darkroom exhaust fan be sure to check the volume it handles so that it is compatible with the size of the room. Also there should be a light-proof vent for fresh air to enter the room. The exhaust should be on the opposite side of the sink (chemicals) for you.

http://www.jeffreyglasser.com/

photoncatcher · Feb 1, 2011

I've spent many, many years working with B&W chemicals, and no health problems. I do wear a resperator when mixing the dry chems, as they have a tendancy to "fluff up" a bit in the air. I think the damp air in my basement dark room may be more of a health hazard than the fumes from my tray of Dektol. I would be more concerned with the color chems. They have alot of pretty toxic stuff in them. Again I have spent many years around E-4, E-6, C-41, and RA4 stuff, and I still feel pretty good at 58. I could tell you horror stories about a commercial lab I worked at for almost 10 years.

Wayne · Feb 1, 2011

Vital, especially for Ilfochrome bleach fumes. If you have a window in the darkroom you can make a darkroom fan setup for a few bucks. Get a 4-6 inch muffin fan or two from a local surplus store. They will probably cost $5 each-you might need to Google to find their cfm rating to make sure you have enough flow. Mount them in a piece of plyood that fits your window-I take my sliding storm window out and put my board right in its place, your window will probably need a unique setup and a little ingenuity. On the outside (I guess it could be inside too) of this board mount a 5 sided "box" of plywood over the fans (with the long open side against the other board) with a simple exhaust opening or louver offset from the fans, with the inside of the box painted black. You're done. Cover the rest of the window.

c.d.ewen · Feb 1, 2011

Just a worry-wort's reminder: watch out for carbon monoxide. If your darkroom and furnace/waterheater share a basement, make sure your exhaust fan is not pulling deadly fumes down your chimney.

Charley

jp498 · Feb 1, 2011

I only do B&W and do not have a fan (and mix dusty chemicals outside). I would highly recommend it for color though, and/or if you do toning with B&W.

Panasonic makes some bathroom fans which are very quiet and you could build a lightproof baffle for them.

andysig · Feb 1, 2011

Thanks for all the replies: I will build a fan into my window blackout. The darkroom will be in the cellar and there is no sink and I will be mixing up jars of solutions more or less as and when I need them i.e. not in massive quantities. I also intend to get a Nova print processor so I imagine or at least hope, that there won't be tons of fumes being created.

jp80874 · Feb 1, 2011

Years ago Kodak published a book on building home darkrooms. They said the air in a darkroom should be changed six times an hour. We all know how healthy Kodak is. I like a strong wind coming through my darkroom and wear a filter mask when working with pyro. As mentioned above Panasonic makes great quiet fans. I have two "inline whisper" fans that hide in the basement rafters, draw through duct pipes from in the eight foot sink, behind the trays and exhaust outside. There is a third higher volume fan, bringing air into the opposite side of the room through a furnace filter to keep out the dust.

A common problem to avoid is to not put the exhaust over head above the trays you will be working in. In that arrangement the fumes rise from the trays, past your nose and out through the fan. The fan in that position is your worst enemy. Have the fan draw from the opposite side of the trays from where you are standing.

John Powers

MattKing · Feb 1, 2011

Good ventilation is critical for health and enjoyment of the darkroom experience.

Bathroom fans can solve the problem. There are also lots of other solutions too. You don't need something that is darkroom specific, as long as the solution you choose doesn't allow stray light to enter.

If you are building walls, consider incorporating light baffles and air ducts in the walls themselves.

GeorgesGiralt · Feb 1, 2011

Hello !
Changing air in a darkroom is an essential piece of gear in a darkroom.
Bear in mind that allergy to chemical comes with time and that your lungs are not easily replaced. So keeping them up to the job is of utmost importance.
IMHO one should push fresh air in and extract "used" air (this will take two fans...) and ensure that the volume of air pshed in is greater that the extracted volume in order to keep the darkroom in positive pressure.
I've constructed an extraction pipe (by making holes in a PVC sewer pipe) which runs on the wall above the sink, so the fumes are attracted away from me and extracted. The blowing fan is on my back when I work on the fan. This way, my nose gets fresh air from outside and polluted air is extracted away from me.
I borrowed this idea from Claudio Bonavolta ( Dead Link Removed ) and it proved an easy design.
Last but not least, if you can, put the fan(s) outside the darkroom in order to get as much noise as you can outside of the darkroom. A lot of fans are quite quiet when new but make a lot of vibrations or grinding noises when they get older....
Hope this helps.

John G1NML · Feb 1, 2011

Clear air is essential to clear thinking as well as health! There is a proper darkroom extractor fans made by Vent Axia -around £300 so a long way from cheap, but if you intend working in your darkroom for significant lengths of time I don't think there is really any choice. It has to be done. Do make sure there is adequate air intake too - filtered for preference. The exhaust air really needs to go directly outside.

Keeping the fug down will improve your enjoyment and make all your darkroom equipment last longer too. You don't need too much to be damaged by dampness before the cost of an extractor is covered several times over.

grahamp · Feb 1, 2011

Since I live in California I have to consider heat extraction as well as fumes and moisture. I have a quiet bathroom model fan which ducts horizontally to the eave of the building where there is gravity-closing vent and flap (dryer type). There is no light leakage. Having the extraction point in the ceiling does pull out heat in colder weather, though. My pocket door provides the air ingress. It is not really possible to seal a pocket door without making it hard to slide, so a separate inlet is not critical in my case.

For short periods, especially if the room is large, you can get by without ventilation, but it is not the best or most pleasant option.

Maris · Feb 1, 2011

My first two darkrooms had the opposite of an extractor fan. A filtered blower fan pumps up the room with excess pressure so that dust and fumes tend to leak out rather than being drawn in. The blower fan can be installed anywhere convenient. Because the blower fan never encounters chemical vapour it tends not to corrode. A light proof exit vent on the far side of the darkroom sink completes the circuit.

How vital is a dark room extractor fan?

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