air ventalation for dark room.

[habib_b]

Hello, I was just wondering if any one would be able to give any suggestions

and advice on where i should look into to to buy a small and affordable air

ventalator for my small darkroom? Thanks.

[charles_stobbs3]

I think an electronics supplier like Radio Shack might have small fans of the type used to cool computer equipment. I would place the fan so as to blow filtered (if posible) air into the darkroom from a clean environment. An exhaust fan would probably suck some air in from under the door and other cracks containing dust.

[mark f]

If it is small enough, a bathroom fan may be enough (I had one on my old 4x5 foot darkroom). I now have a new darkroom where I installed a big Panasonic bathroom ventilating fan that mounts out side the darkroom, and blows filtered air in. That keeps the noise and dust down. It is hard to have too much ventilation and that was my first priority with a new darkroom.

[Gary Naka]

Ventilation is a subject with different ideas.

 

I like the idea of putting an exhaust fan over or near the chemicals, on the opposite side from your enlarger. This is to pull the chemical vapors and smell out.

 

To compensate, you should then install a "filtered" intake filter. Put the intake filter above waist level. If at the floor it will tend to pull in dust from the outside and stir up dust on the floor inside.

[bob_osullivan]

There are several special purpose fans and vents available. Try B&H here http://www.bhphotovideo.com/c/shop/539/Darkroom_Setup_Darkroom_Fans_Louvers.html

 

Or just google darkroom ventilation, there is information out there. And it's important to get it right. Basically you need to determine the cubic size of the room and ensure the the air is completely changed out several times (about 8)an hour. Also, the exhaust fan should be located near the chemicals and the intake vents should be on the opposite side assuring a coss ventilation that always takes fumes away from you.

[g._armour_van_horn]

It's important to keep things clean, so as with any other clean environment (semiconductor fabs, surgery), the fans go outside blowing in. If you really feel you need to have mechanical assistance to exhaust from certain locations, make sure the aggregate CFM of the exhaust fans is lower than the CFM of your makeup air.

 

Most fans are rated at the volume of air they move against almost no pressure at all. If you're blowing air into a closed room, it's likely that the actual volume of air will be less than the rating on the fan. I'd start by taking volume of the room divided by 10 to get six air changes per hour, then doubling that to make sure you really get that many after the door is closed and you toss a rolled-up towel on the floor to keep light out. If your room is 6 x 8 with an 8-foot ceiling, that's 384 cubic feet, so 38.4 CFM will get you six changes per hour, and a standard bathroom fan of 90 CFM should be perfect. Just put it outside the darkroom blowing in, and I'd figure out how to put some filter medium over it.

 

If you have any doubt about what direction the fans should blow, I recommend that you open up a three-year-old computer sometime. I recommend you do this out doors.

 

Van