Darkroom Ventalation.

RoBBo · Mar 6, 2007

Working on turning a very small room into a darkroom.
I know that's not recommended, but it's what we've got to work with.
It's about 7' square, maybe a little longer on one side.
It has one window and a door on the adjacent wall, the plan is that the chemicals would be under the window (To help make the ventilation easier) , and the enlargers (a Besseler 23CII and hopefully a Besseler 4x5) would be on the opposing wall.
I know we will have long printing sessions, and I know photo chemicals aren't good for your brain.
I don't however, have any idea what to look for in terms of venting out the place.
Are there vent's/fans built for this purpose or do we have to create some odd light tight fan apparatus thing?
How close should the fan be to the chemistry and how powerful should it be? Should there be one in the doorway too for a crossbreeze?
What would you recomend for both light tighting the room and the fans/whatever we end up using?

reub2000 · Mar 6, 2007

I don't have any ventilation in my darkroom, and I haven't fallen deathly ill yet.

RoBBo · Mar 6, 2007

reub2000 said:
I don't have any ventilation in my darkroom, and I haven't fallen deathly ill yet.

That doesn't sound quite right.
Do you go on 13 hour printing binges?
Do you have 8 foot ceilings in a 7'x7' room?
And do you have gasmask on during printing?

I was under the impression the fumes from the chemistry generally got quite bad, and the only reason I didn't notice it at school was the fact that they're huge rooms with tall ceilings and good ventilation. Is that not right?

David H. Bebbington · Mar 6, 2007

You might like to start looking here:
http://www.vent-axia.com/products/commercial/t-series-darkroom.asp
A small fan together with a light-trapped vent could both be fitted to the door of your darkroom (easiest solution).

You don't "need" ventilation in a b+w darkroom, the chemicals are relatively low in toxicity. but ventilation makes a darkroom a much nicer place to work and also reduces the long-term risk of allergies, bronchitis, etc.

Regards,

David

Mick Fagan · Mar 6, 2007

Robbo, you should have reasonable ventilation, otherwise the long term effects could be felt in about 10 - 20 years time.

In my darkroom I took out a piece of glass from the window frame and inserted a bathroom wall exhaust fan on a piece of 6 ply board.

I built a light tight box on the inside out of 3 ply board. Very much like the light tight doorways in darkrooms that only have baffles.

You should do a search on the forum for darkrooms, one of the threads is one that shows many, many pictures of different darkroom set-ups.

The smallest regular darkroom(s) I have used over the previous 25 years before I built my current darkroom, were usually converted wardrobes (closets in America) or under stairs type of cupboards. In other words, miniscule rooms

I myself, when doing marathon printing sessions, usually have a break for a cup of hot chocolate about 3 hours into a late evening early morning session. Really gets the creative urge going again.

One of the things I have done in various darkrooms over the years, is to open the door(s) up as reasonably often as I could, this allows fresh and sometimes cooler air into your working environment.

Mick.

reub2000 · Mar 6, 2007

13 hours? I could not do that without many break. Stuff like bathroom breaks, meal breaks, checking "my posts" on apug and my e-mail.

I don't find the fumes to be that noxious. Then again, I've always suspected that there's something wrong with my sense of smell.

Also, if something is bothering you, change to a different chemical. I was getting rashes after using chemicals containing metol, so I no longer use metol containing developers.

Steve Roberts · Mar 6, 2007

RoBBo said:
Working on turning a very small room into a darkroom.
I know that's not recommended, but it's what we've got to work with.
It's about 7' square,

7' square?
Small???
You don't know the meaning of the word! I'd consider 7' square luxury!
My darkroom/dark-cupboard is a walk-in wardrobe off the bedroom. I don't have any (cough) ventilation and (wheeze) have never had any (gasp) problems at all (vomit).
Seriously, I've never had any problems in 37 years of using b/w chemicals and even the smell doesn't worry me. It goes with the territory, as they say, in much the same way as that wonderful smell from a steam engine.

Steve

eddym · Mar 6, 2007

Steve Roberts said:
Seriously, I've never had any problems in 37 years of using b/w chemicals and even the smell doesn't worry me. It goes with the territory, as they say, in much the same way as that wonderful smell from a steam engine.

Smell??? B&W chemicals smell??? Geez, I never noticed that!
Seriously, in the almost 30 years I've had darkrooms, the smell has never bothered me at all. Whenever I hear someone who has recently fallen into the digitrap trying to justify their path down that road to perdition by saying, "Oh, and you don't have to mess with those stinky chemicals," I reply that "I beg your pardon, maybe your chemicals stink, but mine don't. Maybe you should check your pants."

David H. Bebbington · Mar 6, 2007

Joking apart, it is foolish to take any risk with chemicals, particularly if you have a preference for such substances as pyro developer or sulfide or selenium toners. I am personally fairly immune to allergies etc but as a legacy of 7 years professional work as a youth I have a dust mite allergy (which started when I was working in a museum darkroom with a filthy airconditioning system) and also suffer from rhinitis, which means I find it hard to breath if I attempt to do darkroom work when I have a cold. These things may not bother you, particularly if you are an amateur and go into the darkroom only rarely, but once you notice the effects, it's way too late to do anything about it!

Monophoto · Mar 6, 2007

Robbo -

Providing ventilation is a smart move. Health concerns aside, working in the absence of fresh air is tiring. Ventilation will allow you to work longer and more productively.

An important consideration, especially in a small darkroom, is that the ventilation should be quiet. Most commercial ventilators are pretty noisy. I found that computer-style 'muffin' fans are much quieter and can provide excellent ventilation. And they are less expensive. Be sure to get a 120v fan - you don't want to complicate things by having to come up with some exotic supply voltage. Radio Shack sells a nice 120v fan for about US$25.

The ideal ventilation system forces air into the darkroom, which then flows out through passive exhaust vents. The ventilation system also should include a baffle to prevent light leaks and a filter to control dust. You didn't mention where you live, but I would recommend taking air from inside the house rather than trying to bring air in from outside and then have to deal with heating or cooling. It would not be a very big deal to install a ventilator in the space between a couple of wall joists. Install the fan on the wall outside the darkroom with the air flow into the joist space. Construct a frame from wood molding to hold an ordinary furnace filter against a hole in the same joist space that is at least a foot above or below the location of the fan. Cut a couple of baffles that are as wide as the joist space and with a width that is a bit more than half the depth of the space - cardboard or foamcore would be fine for the application. Hot glue one baffle against the inside wall, and the other against the outside wall (so that they overlap) with a couple of inches between. If you want to be fancy, you can paint the baffles and the inside of the joist space flat black.

The exhaust vent can be either to the inside of the house or to the outside - I live in a place where we have serious winter, so I chose to vent inside the house. The construction of the vent is the same as the construction of the ventilator only without the fan, and of course you don't need the air filter. Ideally, it should be as far as possible from the ventilator inlet.

haris · Mar 6, 2007

Hmmm, I live in buliding in apartement on 4th floor of 5 as building have. My bathroom, sized about 2x2 meters and 2,5 meters heigh, have no windows, layout of apatrement and building is such that bathroom is sorrounded by other rooms of apartement or other apartements. Some "ventilation" exist, and it is "hole" 20x30 cm which should lead out of boathroom, but I don't know if that work as it should... Yes, lots of money go to air purificators and room fragrances ... Cheap building for working class socialists I guess . That is "wet part". Dry part of my "darkroom" is passage in front of bathroom, 1mx2m and 2,5 meters heigh, and there are doors between passage and bathroom. And passage have doors which separate it from othe rooms in apartement. So, if nothing I have enlarger out of bathroom moisture . So, I have no choice except to deal with no ventilation or to receive some piece of advice what to do. Is there some "air purificator machine" which filters the air, that is take air and get air out but purified through filters. My only way to get fresh air is to open doors of bathroom and open windows in apartement before and after printing session... No nice at cold winter nights I may say... . Oh, yes, I don't live alone, so no way to work with open bathroom doors, apartement windows and some way of blocking the lights...

Only positive thing is: my bathroom/passage, when lights are off, is in completely darkness, so no need to light blocking materials buying ...

kwmullet · Mar 6, 2007

I think there's a lot of confusion of "fumes" with "smells". Just because you can't smell something, or aren't offended by the smell, doesn't mean there aren't fumes which could be of ill effect to you.

Also -- strictly on personal experience, when I'd work for long periods of time in a bathroom darkroom before I had ventilation, I'd get headaches that would last most of the next day. I've assumed that was from the CO2 content of the air getting higher and higher, the longer I was in there. Think of locking yourself in a bank safe.

I ventilated by opening the bathroom window, and putting a piece of plywood with a Calumet vent fan and accompanying light-tight louvre in the middle. There already was an air supply vent in the ceiling, but before I put in an exhaust fan, there was no where for the air to go.

Remember -- if you pump air out of the room there's got to be a way for air to get in as well.

Somewhere (maybe someone has the link) Kodak has well-quoted recommendations for the number of times per hour air must be exchanged in a darkroom. I won't guess at it here and pollute the thread with wrong numbers.

Best to pull the fumes from your sink away from you rather than across you, so if your sink is between you and the window/exhaust vent, and you've got adequate supply ventilation, then I'd guess you're on the right track.

Look in the sticky darkroom portrait thread for lots of good pictures of hgih-quality darkroom ventilation setups and discussions thereof.

For my current darkroom, I made a passive supply vent inbetween three studs with some scrap lumber to make an "S" trap and some flat black paint. Works fine, even better since I put a little assist fan in front of it (of course, now, it's not longer passive).

My general feeling is that when putting in vents, it's easier to undo a hole in the wall than a hole in a door, and a wall is thicker, so you can more easily make an "S" trap, then someday when you move/sell/use another room for the darkroom, you can just pull it the vent off, put up a bit of wallboard, spackle and touch-up paint and viola!

-KwM-

Jim Jones · Mar 6, 2007

Since extensive modifications are impractical in rental property, the window might present the best ventilation. A panel that can fit beneath a partly open window can contain a light trap and exhaust fan. Perhaps enough air can leak in around the door for circulation. I've worked long hours in small unventilated darkrooms without ill effect, but some people are sensitive, and must exercise care.

Seven feet square with two enlargers? I hope it is coed. That would make those long printing sessions more pleasant!

jeroldharter · Mar 6, 2007

I agree with the need for some ventilation and provision fro return/fresh air so that the vent fan is not drawing against negative pressure.

You might also focus on reducing exposure. I have a fairly large darkroom with a good vent fan but rarely even turn it on. I use single tray processing so that all of the chemicals are stored in large plastic pitchers (less surface area for evaporation) rather than trays. I pour in each chemical in sequence and then pour from the tray back into the respective pitcher. The pitcher can be covered with a plastic dinner plate or plexiglass when not in use and that substantially reduces fumes, especially when using selenium toner (also reduces staining).

I think it would be good for a small darkroom where you don't have alot of room for multiple trays. It also allows you to use various developers in the same session wothout needed a separate tray for each one.

Bob F. · Mar 6, 2007

Nova vertical slot units help keep fumes down (and take up less room than trays) and combined with low odour fixer and odourless stop bath mean I do not need to switch my fans on. Rotary units such as Jobo will also help keep odours down.

However, the Novas are fine until you want to print larger than the capacity of the unit you have, and then you are back to tray(s) and large surface areas. I am somewhat susceptible to fixer fumes and even using the low odour versions in a tray, I do need forced ventilation to avoid a sore throat after a couple of hours.

You can buy light-tight fans but they are rather expensive. I use two 6" extractor fans fitted to the window surround such that I can open the window and the fans suck air out of the room via a DIY light baffle made from plywood and matt black paint. Heavy mount-board would probably work too.

Incoming air comes via the gap under the door. Not exactly hi-tech but it works as the hallway the door opens on to has no windows... The door could be sealed and a simple light-baffle installed covering a cut-out but the door would need replacing when I sell the house. If you go down this route, I suggest removing the existing door, storing it for later replacement, and fit a new door as tight-fitting as you can and add strips of foam around it.

As already suggested, a half-hour (or three...) spent reading through the (there was a url link here which no longer exists) will be rewarding.

Good luck, Bob.

Mark Fisher · Mar 6, 2007

A pretty effective light trap is simply some dryer vent hose (4 inch dia.) with a couple of bends in it. Spray paint the inside with flat black paint and it is pretty light tight. Add a bathroom fan (preferrably blowing into the darkroom) and you are set. My last darkroom was 4'x6' and it worked well.

Vaughn · Mar 6, 2007

More important than ventilation air exchange is the location of the intake and exhaust vents.

If your head is in the path of the exiting fumes, then one might as well not have ventilation. Ideally, one has the fumes sucked up right above or behind the trays, and fresh air comes in pass one's head.

I silver printed for 15 years in a darkroom with poor ventilation -- no problem at all. Some others (we did a survey...we have 150 students/semester) experienced headaches, etc in a relatively short period of time. Some student (and myself) can just about bathe in Dektol -- other students' hand will show signs of contact dermatitis the first time they touch Dektol. One can never tell.

After 5 years of platinum/palladium printing I have developed a very bad reaction to pd/pt dust.

If one uses an acid stop bath and/or fixer...and has asthma, then excellent ventilation is a must.

Vaughn

reub2000 · Mar 6, 2007

Providing ventilation is a smart move. Health concerns aside, working in the absence of fresh air is tiring. Ventilation will allow you to work longer and more productively.

Another important factor is the safelights. Insufficient lighting can be fatiguing. I need to improve the safelights in my darkroom.

My darkroom is very large, and I do open the door pretty frequently. After I fix a print or test strip I will turn on the light and open the door.

dancqu · Mar 10, 2007

reub2000 said:
Another important factor is the safelights.
Insufficient lighting can be fatiguing. I need
to improve the safelights in my darkroom.

For a high level of darkroom lighting the use of Graded
papers is the way to go. I've strung three small orange-ish
yellow safelights under cupboards where once were washer
and dryer. A single larger unit illuminates the enlarger area.

Safe fuming odorous chemistry is available. A few
years ago when restarting darkroom work I ordered
up the usual bunch. But this time the darkroom was
in house. Did not like the odors so shelved all but
the developer and switched to odorless. Dan

Bob F. · Mar 10, 2007

reub2000 said:
Another important factor is the safelights. Insufficient lighting can be fatiguing. I need to improve the safelights in my darkroom.

The simplest answer is orange or red LED safelighting. Amber LEDs work well too, but you can go brighter with orange. Sodium vapour lamps do a good job but replacing the lamps can get very expensive. Another alternative is to use localized lighting over the trays using smaller LED safelights - I quite like this approach as it keeps the light away from the enlarger easel so I can see to dodge/burn etc and a larger light bounced off the ceiling stops me bumping into the furniture...

If you are happy with red, the kind of lamps designed to replace halogen lamps will fit in standard fittings and give out 20W equivalent of light each (enough to read a book by at 6 feet or more distance). I tried three in a fitting bounced off the ceiling but I find red light too intense and depressing, so switched back to my DIY orange & amber LED safelights.

Cheers, Bob.

Paul. · Mar 11, 2007

Bob are you talking of low pressure sodium SOX lighting as a safe light and what wattage do you use please? is 35w sufficient in a 7x10 foot darkroom?
I ask as high pressure sodium SON lighting gives a white ish light rather than orange.
A lot of public authorities are moveing to SON street lighting for its better light output hence fewer lights and cost saveings so that low pressure SOX lamps will become harder to get and more expensive as time goes on.
It may be possible to get an old 35 SOX lantern from the local council when they upgrade their lights to SON ones.
Regards Paul.

Bob F. · Mar 11, 2007

Paul. said:
Bob are you talking of low pressure sodium SOX lighting as a safe light and what wattage do you use please? is 35w sufficient in a 7x10 foot darkroom?
I ask as high pressure sodium SON lighting gives a white ish light rather than orange.
A lot of public authorities are moveing to SON street lighting for its better light output hence fewer lights and cost saveings so that low pressure SOX lamps will become harder to get and more expensive as time goes on.
It may be possible to get an old 35 SOX lantern from the local council when they upgrade their lights to SON ones.
Regards Paul.

Nope, sorry: I'm talking about ones made specifically for the Darkroom such as the Duka 50 and Dead Link Removed in the US. I have a Duka 50 and replacing the lamp would cost me over 120 GBP - call it $250 US... Big surprise: I made my own LED lamps instead!

Cheers, Bob.

RobertP · Mar 11, 2007

Vaughn said:
More important than ventilation air exchange is the location of the intake and exhaust vents.

If your head is in the path of the exiting fumes, then one might as well not have ventilation. Ideally, one has the fumes sucked up right above or behind the trays, and fresh air comes in pass one's head.

I silver printed for 15 years in a darkroom with poor ventilation -- no problem at all. Some others (we did a survey...we have 150 students/semester) experienced headaches, etc in a relatively short period of time. Some student (and myself) can just about bathe in Dektol -- other students' hand will show signs of contact dermatitis the first time they touch Dektol. One can never tell.

After 5 years of platinum/palladium printing I have developed a very bad reaction to pd/pt dust.

If one uses an acid stop bath and/or fixer...and has asthma, then excellent ventilation is a must.

Vaughn

In a classroom setting I would over emphasize safe darkroom practices. Always glove up and wear a respirator when ever applicable. When mixing dry chemicals I would shut the fans off and wear a respirator. I always run hot water in the sink to bring the humidity up before I ever get the palladium and ferric oxalate out of the cabinet. Or any of the dry chemicals that I'm working with. This will help settle any dust and particles in the air. I always wear surgical gloves but then again I have an endless supply of them. Just remember to turn the fans back on once you get everything into solution. You can always make the MSDS required reading and take the fun out of the photography class too. (just joking) I've seen a bad case of dermatitis from a metol reaction and it is not a pretty site. And once you react you will never be able to use that developer again. If you're having bad reactions to palladium I would suggest all the above. Respirator, gloves, long sleeves, maybe even a baseball hat/ hair net. It is virtually impossible to weigh and mix palladium powder without some getting airborn so a full-face clear shield would probably be a good idea also. I know this all sounds like a lot to be able to work and be comfortable at the same time. But it's like wearing a seat belt, once you are use to it you'd be surprised how tolerable it is. You're right on about the direction of air flow. You definitly don't want to pull the fumes into your face. Most of the darkroom fans you buy come with a pretty good diagram showing the proper ventilation flow and how to rig your exhaust fans and passive intakes. There's probably numerous diagrams and designs in books and on the internet about darkroom design. If handled properly any of the chemicals we use can be used safely. The only one that still makes me a little nervous is the potassium cyanide used for fixing wet plate. That's one where a mistake could prove costly. So the nerves seem to make my focus a little sharper when handling it.

pnance · Mar 15, 2007

13 hours! Do you wear a catheter?

Darkroom Ventalation.

haris

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