Need Darkroom Ventilation Ideas for Old Bathroom

[kristine_mccourt]

Hi, I am trying to convert my bathroom to a B&W darkroom for the first time and am wondering about

ventilation. I live in Hawai'i and many of the older homes here were not built with ventilation systems in

the bathroom. What I have are two louvered windows, one big (about 2-1/2 ft. x 3 ft.), one small (1-1/

4 ft. x 1-1/2 ft.). I was wondering if anyone had any suggestions on what kind of ventilation I should

use. Can I just use a fan? Do I need to have air circulating inside the darkroom and something

extracting the fumes outside as well? Things like that. Any information is greatly appreciated. Thanks a

million!

 

Aloha,

Kristine

kmccourt@hawaii.rr.com

[mike_earussi1]

I didn't have any ventilation in my basement either, nor outside window, so I just used a good air purifier with activated charcoal filter with built-in negative ion generator. Thankfully, it worked just fine.

[john_stockdale2]

I use a mains voltage small computer fan to extract air to the outside. It's only about 3inch in diameter and it's in a box to stop light coming in from outside. You could use a low voltage one and use a plug pack power supply, which would be safer if you don't want to mess with mains voltage. Both are cheap.

 

Fixer is the main problem (SO2 gas) and stop bath also a problem (acetic acid). I use fixer designed for C41 (ordinary colour) processing which is cheaper and smells less. There are odorless stop baths too (citric acid I think is used).

 

You don't want a fan that's going to stir up dust.

[discpad]

You don't want an exhaust fan -- When you create a negative pressure, it will draw in dust.

 

 

Instead, you want to reverse the fan and push air INTO your darkroom...

[Gary Naka]

Where in Hawaii do you live? I used to live in Palolo Valley.

If you live in the upper valleys or windward side, the humidity level will keep the dust down.

 

OK first 2 dark rooms were my moms kitchens. NO ventelation at all, once my brother and I got the room light sealed. My 4th and later darkrooms was whatever bedroom I had in rented apartments/houses, again no ventelation.

 

If possible you do want fresh air coming in, but more important for the smelly stuff to go out. Are the jelosies (I could never spell that word) glass or wood? Is there a light souce outside the window that you have to deal with? My moms kitchen has a street light pouring into the window. If you don't have a light source, you're lucky. If not, you can make a light trap to let air flow in but baffle the light. One question, do you have natural air movement between the 2 windows w/o using a fan? If not just use one fan to suck air in, or blow air out, whichever one is easier to do.

 

If you can't ventilate, you should select chemicals to minimize the smell. Example stop bath can be pretty strong smelling...phew... So can fixer, but to a lesser degree. There are chemicals that are less "smelly" or at least tolerable. One thing I learned, mix the stop bath soltion from the concentrate OUTSIDE the house...double phew. Then periodically, take down the light blanket from the window, open the jelosies put up the fan to change the air.

 

You should get on a list to rent my fathers house when he finally gets around to moving to my brothers house. There is a darkroom under the house...and I miss it :-(

 

aloha from an expat, Gary

[gurney_tim]

Hi,

 

You made find this of use:

 

http://www.novadarkroom.com/

 

go to the section misc darkroom and ventillation.

 

This fan circulates/purifies the air with no external vent they quote:

 

Filtaire 300 Air Purifier Ref: AFILTAIRE

The Filtaire 300 Air purifier seriously improves the quality of the air in your darkroom. Purification and re-circulation of existing air in a room is a distinct advantage. You do not bring in unwanted dust and ensure odours are efficiently removed. After extensive trials the Filtaire system has been found to alleviate allergies and irritants by completely filtering the air around you. It works by drawing air into the central spinning core at a rate of 6 cubic metres per minute and pushing it out through three polyester dust collecting filter discs removing particles as small as 0.03 microns. This serves to dispose of the majority of chemical vapours gases and odours. The competitively priced Filtaire 300 unit can be wall or bench mounted and has two speed selections. Ideal for home darkrooms offices and normal rooms of upto 90m�.

 

You will be able to find a similar product in the states.

 

Cheers

Tim

[Gary Naka]

Tim, That looks like a HEPA filter. Can be picked up at Costco (our favorite warehouse store). But I didn't think it would handle chemical smells. For that you would normally need charcoal filters, and the one on most HEPA filters are not what I call real charcoal filters.

[wendell_kelly]

For your darkroom, you'll want to be circulating fresh air into the room constantly. Both the fixing bath and the stop bath do have odors and a closed room will become stuffy if you're working in it for any amount of time. The amount of circulated air (in terms of cubic feet per minute, cfm, will depend on the size of the darkroom. You can find guidelines on the websites that discuss darkroom design.

 

A simple solution might be to buy a purpose-built darkroom ventilation fan. B&H sells the one (a Delta) which I use and it has adequate capacity for a 10'x10' room. It would mount in either of your windows (on a plywood panel) and comes with built in light baffles and is already wired with an electrical cord. If you're good with tools you can build much the same thing with an ordinary bathroom ventilation fan, improvising the baffle system. Having done it both ways, I recommend buying the Delta if funds permit.

 

The ventilation will work better if you can make some provision for clean air to enter, rather than have it sneak in around the door. Pehaps you can improvise a baffled vent in the other window.

 

The discharge air can just be ventilated to the outdoors. It makes no difference if a fan blows in or blows out, dust will follow the air current.

 

Sulfide and selenium toners have the possibility of emitting toxic fumes. If you choose to work with these in the future, revisit the question of darkroom ventilation.

[gurney_tim]

The filter is said to reduce odours and I have no idea if it is like a hepa filter but they quote also:

 

A British manufacturer, Patent Filtration, produces a range of equipment aimed at eradicating these problems. Their filter units are not extractors or ionisers but work on a principle of filters, which rotate at high speed to create a centrifugal force. It then processes the air drawn by removing particles down to minute levels. A further set of treated static filters then receives the air and extracts from it chemical smells usually found in darkrooms.

 

Due to this unique process, there is no need to vent air out of development rooms or to introduce "fresh air" from outside. This gives the following distinct advantage of constant temperatures then prevailing throughout the development process. You will also find that no foreign bodies come in from outside "fresh air" and those already in the room are trapped in a contained unit.

 

The biggest leap forward with this technology that we found when we first tried a unit was that the noxious fumes are neutralised within the room. This improves your working environment and unpleasant smells do not permeate to other parts of the building.

 

The equipment can treat the following odours, all of which you regularly find in the development process:

 

Acetic Acid, Benzene, Bromide, Selenium, Sodium Ammonium, Sodium Thiosulphate, Sulphuric Acid, and Trichlorothylene amongst many others.

 

Three models are available. All are mains powered. We would recommend the Filtaire 300 model that is freestanding or can be wall mounted. Manufactured in white ABS, it is portable, and weighs only 4 kilograms. It looks like, and occupies about the same space as, a deep-fat fryer. It's ideal for rooms of around 60 cubic metres where all the air will be exchanged every 10 minutes. It uses about the same electricity as a 100w light bulb so can be left on all day at minimal cost.

[david_elden]

The main thing is to have fresh air entering the room and room air leaving the room (and building) while you have open containers of processing chemicals in use. How much air? I suggest reviewing this Kodak information, the section on ventilation on page 4 provides soem guidleines.

 

Here is the URL of the Kodak document:

 

http://www.kodak.com/global/en/corp/environment/kes/pubs/pdfs/J98A.pdf

[wendell_kelly]

If I may follow up on David's comments-

 

The sensation of "stuffiness" in a closed room is the human sensory system reacting to an elevated level of carbon dioxide in the room - the source of the carbon dioxide is the people in the room, we emit this as we breathe.

 

Recirculating systems with absorbants do not remove the carbon dioxide; the way to accomplish this, and render the room comfortable to work in, is to bring fresh air into the room and dump stale air overboard.

[Bill Bowes]

Hello everyone. Here is my "simple" solution to the darkroom venting. Hook up two (2) 12VDC computer cooling vans to exhaust the darkroom air OUTSIDE the room. Place these fans so that your work area is in the middle of the inlet/exhaust pathway. These can be run off a 115vac wall wart. Put these fans BELOW the chemistry area so air is sucked away from your nose. Now you must install an INLET hole about 1/2-3/4 the area of the two fans. You can find circular closet air inlets at most big box hardware stores. Purchase a scrub pad with large, open material and cut it to fit inside the inlet...this will filter most debris...clean it once a month. Cheap, EZ and has been working for about 10 years for me. Enjoy, Bill

[marc_hershman]

<p>I havee a question can I install a bathroom exhaust fan in my laundry room where I am setting up my darkroom. I would have someone put it in the ceiling and exhaust it through the wall a few feet away with some metal duct work and a dryer type vent cap ouside. The piel would be in the ceiling and joist space. I don't know if the standart exhaust fan would be light tight enough.<br>

Thanks</p>