Good Darkroom Fan Recommendation?

I use a 12" square Delta fan right above my chems. I did a smoke test and wasn't very impressed with the thing. I get coughing when I'm in there a while which tells me I need to upgrade that thing. Can anyone recommend a good strong fan?

Thanks

I bought one from Grainger and they carry many. It really moves the air and will change the air in my DR in a couple of minutes. It is ducted to the outside. Air comes into the DR thru a door vent. The fan is, however, quite loud, and I only use it for a few things. The chemicals I use have little or no odor.

Panasonic makes some quiet bathroom fans if you want one to leave it on all the time.

I experienced the same thing Bob and am also interested in a stronger fan that will fit in the 12x12 proportions. Possibly an industrial bathroom fan? I will do some research myself and wait for other recommendations. Excellent post. My next darkroom will have a dedicated hood with enough suction to lift a piece of tissue off of the sink.

Cheers!

That's what I'm talking about Michael!!!

I used an external-mount 900 cfm kitchen fan ducted to fit a smaller opening along the back side of my sink, just above the trays. But it's more a matter of efficiency. Check this APUG (there was a url link here which no longer exists) and see how PeterB handled ventilation. I was impressed!

The type of exhaust pipe, length, and number of bends has a significant impact on the efficiency of the exhaust. Changing from corrugated pipe (if that's what you have now) to straight pipe would likely have more impact then increasing the fan cfm (unless you are at a very low cfm now).

Centrifugal fans will move an amazing amount of air and are really small. Get one cheap off of ebay. Forget out those little kitchen fans.

I bought two 5 or 6 inch muffin fans and mounted them to a light-tight baffle that I put over my window. The fans cost $5 each at a surplus store, and are overkill for my HUGE darkroom space. Even one would be adequate for most darkrooms.

Wayne

If your fan is right above your chemicals, where is your nose? Many people stand in front of the sink holding the trays. If that is your set up, you are sucking the chemical fumes right by your nose and mouth. A cough or several should not be a surprising result.

I have two Panasonic whisper fans in the rafters over the sink, but I have four inch PVC pipe from the fans angled to the opposite side of the sink sucking the fumes from the trays away from me to the other side of the sink and then up and outside. The fewer angles the more suction.

The air going into those fans has to be replaced or you have a vacum. I have a larger fan on the wall behing me pumping filtered air into the room and toward my back. The room is 11'x13'. This is also a Panasonic whisper fan. They are very quiet, but they cost more than equal capacity bathroom fans.

Safe air to you.

John Powers

I have a 6" rackmount muffin fan, 115 VAC, plugged into a Variac (like a super heavy duty dimmer) that evacuates my darkroom. Nice to be able to vary the noise level.

I plan to get another one from here: http://www.meci.com/

It is just up the road a few mintues from me and has amazing stuff...

This would also be a good fan/filter for a homemade film drying cabinet.

http://www.meci.com/product_info.php/cPath/540_45/products_id/2900664

I have a larger bathroom fan in the ceiling in the corner above my sink. On the opposit wall and lower I have a Delta light-tight louver. Don't forget that you need return air so you don't really want a helicoptor rotor sucking all of the air out of a small space. You might look at Panasonic bathroom fans which are reported to be quieter.

My darkroom in still in the planning stage. I was going to put an exhaust fan right above the trays. Perhaps it would be best to mount it in the wall right behind the trays. Comments?

Another important factor is allowing fresh air to enter your darkroom. A light tight vent situated opposite of your fan should help in getting air to cross flow through and out of your darkroom. If your darkroom fills up with stagnant air it is probably because there is not enough air flow. We usually make our darkrooms so light tight that we neglect to accommodate the allowance of sufficient fresh air into the room that helps in removing stagnant air. Just make sure you have sufficient air flow through your darkroom.

mgb74 said:

My darkroom in still in the planning stage. I was going to put an exhaust fan right above the trays. Perhaps it would be best to mount it in the wall right behind the trays. Comments?

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I wrote to this above within this thread. I would add that the fan sucking air into the darkroom is built into a box. The other end of this box has a high quality replacable furnace filter to keep out the dust and dog hair on the other side. Are there any other details you would like or are you looking for other opinions?

John Powers

I have a 12 inch square Doran light-tite in the corner of the wet side, that exhausts through a flexible duct pipe directly to the outside of the house.
I cut a hole into the darkroom door, opposite end, and installed a 12 inch Doran light-tite louver to allow fresh air into the room from the entire basement area. I can stay indefinitely closed up, and have never noticed a major smell, other than the beer I spill on the floor.

jp80874 said:

I wrote to this above within this thread. I would add that the fan sucking air into the darkroom is built into a box. The other end of this box has a high quality replacable furnace filter to keep out the dust and dog hair on the other side. Are there any other details you would like or are you looking for other opinions?

John Powers

Click to expand...

I was referring more the the placement of the exhaust fan itself - putting it in the wall, just above the level of the sink to avoid pulling fumes in front of my face. The extract duct and bends would decrease suction, but that might be acceptable. One problem might be the depth of the wall; I don't know if I can find a fan that will fit in a 3.5" space. I'm sure I can rig something up with muffin fans if necessary. Or build it out from the wall.

As far as air intake, I have a passive vent planned - with a filter. Most darkrooms are not all that air tight, I want my filtered intake to be the easiest place for air to enter. As far as dog hair goes, we have an aussie shepherd and expect to have enough to knit a sweater about every week.

I think putting the exhaust fan opposite you when standing at the sink with the fan at sink top level is a perfect start. I can’t find the Kodak book on building a darkroom right now so someone else step in. I think the minimum figure they gave was that you should change the air in the room every ten minutes or six times an hour. I am not familiar with a muffin fan. It sounds bite size, but I don’t know. You need to calculate the cube of the room and determine how much air the fan will exhaust in that position with the bends you mentioned. I personally feel a good strong breeze is life insurance and have added fans accordingly. I value the silence of the Panasonic Whisper fans. I either want to listen to music or think undisturbed.

Ideally you want a sealed dark room pressurized by your intake and relieved by your exhaust. If as you say air is coming in from all sorts of places, those places have probably been there a while and dust will arrive with your air. That defeats all the reasons you built the darkroom in the first place. Another consideration of those openings is that light may be fighting to get in with the dust and air. After you have gotten tired and hot building the darkroom, a good cool off is to turn on all the lights outside the darkroom and above if this is in the basement. Close the door, turn out the darkroom lights, sit down and wait five minutes to adjust your eyes. Then move around, up, down, all around to look for light. If you see any you probably aren’t seeing the dust that will come in with it. If you can see where you are going there is light in the room. When I finished building my darkroom I did this and then spent some time caulking places I had missed. The payoff on dust comes when you do a series of twenty enlarged prints that don’t need spotting. I print mostly 16x20.

Just a side note, I mentioned in the earlier post that my fans are in the rafters and I use 4” PVC to get down to the sink level. I would prefer to go directly through the wall, but my darkroom is in the basement, below ground level. The other side of the sink wall is about four feet below ground level.

Hope this helps. If not please ask.

John Powers