ventilation for home darkroom

I am going to be setting up a darkroom within a very small room and

woundering if anyone has tips on ventilation.

There are many ways to go. FWIW, I use a small mains voltage computer fan. I blows air into the darkroom, and can be fitted with a filter. The low air speed minimises dust being blown about. I use neutral fixer, which means far less odour.

Correction to above post "It blows..."

I also use a fan blowing in except I'm using a small bathroom fan mounted on the outside wall. With this arrangement you do need an elbow or some other sort of baffle to keep things light tight. I also have an exhaust to the outside to keep the chemical fumes out of the house. Works great. Your darkroom looks spacious compared to mine (mine is about 6'x 4')

thanks, any ideas though on what i can do during the winter when the windows closed? a air purification system?

Billy I am not sure what your set up is going to be exactly, but it seems like the vapors from a regular dev/stop/fix process affects different people to different degrees. If you are using 8x10 trays, and going in and out the door every so often, you're moving air. Where ya are moving it to, I don't know.

 

I don't turn the vent on continuous unless it's 16x20, or if theres selenium or bleaches involved. Then the vents on, the doors open and a shop fan is in the doorway.

 

The vapor pressure from three 8x10 trays at about 70f is low. If that's your living space outside the door, I would be more concerned about ventilation. I don't mean to sound cavalier about it.

Some ideas,

 

The positive pressure filtered air idea is a good one, possibly the best if you have a place to mount a fan outside the darkroom that has a filter. Alternately, you can seal the room well, install a light-proof box/holder for furnace filters and use an exhaust fan. I had a set up like this for a while and it worked extremely well. I built a baffled box for the furnace filter and mounted it in a hole I cut in the hollow door. The exhaust fan was a normal (quiet) bathroom exhaust fan into the attic. To keep it light tight, I used about six feet of exhaust hose and simply tied it into a knot (being careful not to kink it or otherwise impede air flow) and fastened it to a vertical stud, exit hole down.

 

There are many commercially available light-tight fans available. Check Calumet, etc. Some of these come with filters.

 

If you do mount an exhaust fan, try to have it above the sink (in a hood is ideal, but not necessary for B&W) in order to better exhaust the fumes from trays.

 

To minimize odor in the darkroom, try to use an odorless fixer (the main culprit). I find that a rapid fixer without hardener is not too smelly.

 

If you really can't manage a fan, and you will primarily be printing, you can always open the door between prints and air things out. This gets to be a bit of a hassle though.

 

Best,

I use a poorly ventilated bathroom as a darkroom. With a nearly odorless, neutral fix (Agfa FX Universal) and a water bath instead of an acetic acid stop, the lack of ventilation is no problem.

The issue of air quality/ventilation is currently the deciding factor for me in building my basement darkroom... Some of my concerns are: first off safety of fumes circulating throughout house, wife complaining house smelling of chemicals, and heated air being exhausted to the outside in winter (don't think this will be a trivial cost in the mid-atlantic states this winter, especially if you have natural gas forced air heat...)

 

So, ideally, an air purifier sounds like a great option... Has anyone ever used on in the darkroom? Do they really clean the air or just mask the fumes? Just because I don't smell it doesn't mean it can't hurt me...

 

Here's one I saw on BH...

 

Cachet Eco-Aire 8000 Air Purification System

http://tinyurl.com/dlfgg

Small, poorly ventilated dark rooms is exactly why we provide "odorless" chemicals for that appication.

I can not emphasize enough the importance of fresh air in the darkroom. The best solution is positive pressure, with the exhaust going outside. Next best is a fan exhausting to the outside. If the room has a window, it should be fairly simple to exchange a glass pane for a thin plywood sheet with the light-tight fan. Or even a fan mounted in a box which extends under the door threshold to pressurize the room, and exhause through a cracked window. I have a window exhaust fan on a rheostat, and adjust the speed to the process. Under normal darkroom operations, I exchange about 10 changes per hour. During certain processes, like toning, I must increase that at least 2x. Exchanging the darkroom air with that of the house in which you live is not the answer.

There are many discussions in the b&w photo archives on this topic. Just use "darkroom" and "ventilation" as search terms.

 

In virtually every such discussion my usual comments can be summed up as: Don't worry about it.

It depends on the operations you're about to do there. If you plan to develop B&W films and enlarge paper prints from them, you do not really need any ventillation. Film and paper developers, fixers, etc. are not smelly at all, they are totally safe to handle without ventillation. However, it's better to work in fresh air than in heavy and warm air...

 

If you plan to do some reversal processing, you might need good vetillation because of some nasty bleach containing e.g. sulfuric acid.

Hello everyone. Think differently...suck the air out of the darkroom, and keep the fan that does this below your chemical trays. Nasty vapors are pulled down (away from your face). If needed, a small filter can be installed in the door that leads into the darkroom... enjoy, Bill

An indirect answer is to use a Nova slot processor. Although expensive, it would save you space in a small darkroom and minimize the need for extra ventilations.

 

With your layout, you have no easy way to supply return air so even if you have an exhaust fan, it will be sucking low pressure without return air.

With an amateur darkroom the usual saga is it "use and exhaust fan above the trays". This draws the fumes outside; but draws in micro dust and dirt thru every baseboard abd door crack. <BR><BR>In a professional darkroom; the entry point of inlet air is at least filtered; to radically reduce dust entry. This reduces dust. In a really pro settup; the darkroom is pressurized so there is NO entry of dust. The room is caulked well; "fraction of inches of water" gauges are installed to measure the delta P; and the gauge has a tell tale alarm contact to alert when there is a breach; ie low pressure. The inlet air is controlled; filtered. A electostatic air cleaner can be at the inlet; making a clean room like darkroom. Clean rooms develooped during WW2 did this with a HEPA filter. Today a HEPA like filter is available at Walmart; the 3M Filtete series; filtering down below the micro level of dust, pollen and dirt. <BR><BR>Women and small kids tend to be more sensitive to darkroom chemicals then grown men. An exhasut fan baove the trays is decent start; but strive to define a controlled filtered point for the "makeup air" In several rental houses I just bought a cheap door; and placed a 20" box fan and filter in it; and swapped out one door. When we moved again we just drove the doors pins out; and placed the landlords door back.

I'm shopping for a fan right now. I give more info later. However, to think you're exhausting just because of the smell is probably way off base. The issue is poisonous fumes which are there whether or not you can smell them. Set up a good exhaust system that takes the air outside. Exposure to these chemicals will destroy your nervouse system at a minimum.

<p><i>The issue is poisonous fumes which...will destroy your nervouse system at a

minimum....

</i></p>

<p>This is a load of nonsense.</p>

 

<p>There is very little in the darkroom. other than maybe toners or pyrogallol/-catechol,

that is going to kill anyone unless you drink the stuff in mass quantities. Common sense,

an adequate supply of which is called into question by such hysterical and unfounded

foamings-at-the-mouth, is all that is required to avoid harm.

</p>

 

<p>People working in confined spaces, <i>eg</i> most darkrooms, exude moisture and

odors from skin and breath. The aqueous portion of darkroom solutions evaporates, and

some chemicals are volatile and add to the vapor content of the air. This is why enclosed

spaces like darkrooms become "stuffy" and uncomfortable for persons and printing

papers, etc, which is why they require ventilation. You ventilate to keep the air fresh and

comfortable for human habitation, and to avoid spoiling things like printing papers.

</p>

 

<p>In cooler dryer climes an exhaust fan with a filtered air inlet are all that's required to

keep the air fresh. You may need air conditioning where it's hotter or more humid.</p>