Darkroom ventilation?

[kr236rk]

For my third and best darkroom I insisted on no ventilation but air conditioning instead. The climate here in Noosa, Australia is sub-tropical and the darkroom can be too hot to work in for half the year. An extractor fan would pull expensive conditioned air out faster than the 2.5kw air-con can temper the fresh stuff coming in. Net result is electricity consumed but temperature control lost.

I've no direct experience of this but the cold climate answer to a comfortable darkroom is a reverse cycle air conditioner in heating mode. This is the most energy efficient way to heat a room. Again an air extraction system can defeat the heater and the room goes cold.

What about the fumes? By far the worst smell in my B&W darkroom was acetic acid stop bath so I've eliminated it; won't have it in the place. I use Fotospeed SB50 Odorless stop bath but there are other brands. That's one problem solved.

What about fixer? Acid fixer tends to give off sulfur dioxide, phew. Alkaline fixer tends to give off ammonia, phew. I use Fotospeed FX30 Odorless fixer which is strongly buffered to neutral: no SO2, no NH3.
Another problem solved.

The developers I use, mainly Dektol and Xtol, have negligible smell and the volatile they emit is water vapour; not a problem.

When I'm not running the air-con and I want a change of air in the darkroom I just open the door and go out for a walk. Works well, costs nothing.

That looks like darkroom heaven My old darkroom had a passive light-proof vent in the door, such that air could percolate in through a light trap in the boards which slotted in against the window - those overlapping boards were also covered by a heavy curtain - but air could freely sift in around the edges.

My new bathroom is different, the door leads into a passageway with no direct air drafts, one way or the other - whatever grille I put in that door, it would create no air-flow, so I need 2 light-weight fans, one in, one out, just to take the edge off the fumes, nothing too drastic.

 

[kr236rk]

hi kr236rk

ventilation is good. there are only 3 solutions.
ceiling fan and exhaust outside,
window fan and exhaust outside
door fan and exhaust inside
window fan seems like an easy option.

Yes, I will construct a double fan unit to lodge in the upper vent window, allowing it to open. The vent has a deep recess on which the fan unit can rest. Advantage of deep double glazed units, in this case.

First of all, I have to construct the outer baffle 'box' of mesh, which will enclose the open vent window, plus fan unit. When that is in place, I can then construct the fan unit to sit inside it.

The whole thing is hooked & clipped in place, all of it, & can be removed to storage, when not in use.

It will be a step-by-step project, to get it up & running.

Mega DIY.

 

[kr236rk]

here is my setup

Thank you - I used the room under discussion for processing cine film, so the light-proofing is basically still intact & ok.

 

[FeS2]

One wall of the DARK room part of my basement has vertically offset vents. A fan directed to the outside lower (ankle level) vent can't blow turbulent air thru of the inside ceiling level vent.

 

[kr236rk]

Now have gathered together the basic bits & pieces for ventilation, will update on progress, thanks.

 

[kr236rk]

Work in progress

 

[kr236rk]

Had to drill two loop holes through the light-trap frame for the 40mm pipes, one for air in, one for air out. Pipe extensions will reach up into the open vent window space, beyond which will be a mesh 'basket', keeping insects out of the pipes & darkroom. The pipes will also have medium-weave, mesh baffles in them, against insects & so forth.

The wooden box has an extractor fan inside it.

 

[kr236rk]

up & running.

The double blind unit cannot stop all daylight seeping in, between the woodwork, I'd have to go round all the inner guttering with sealant, probably impossible - or would take years of 'hit-n-miss'. This restricts me to developing prints at night - not a problem really.

Need a work surface (shelf) for an exposure lamp, then I can develop some bw slides - maiden voyage for the darkroom.

Might also get the safe-light installed as well, for good measure

 

[grain elevator]

Are the light trap boxes necessary with the black tubing having two 90° bends anyway? Especially if you only deal with paper and can do film stuff without ventilation?

 

[snusmumriken]

Looks very neat. Do you not get a lot of noise in those narrow pipes? My pipes are the full 10cm and direct through the wall (no bends). Light trapping is done by covers over the fans, attached by magnets. I realise this won’t help you, @kr236rk, since you can’t bore holes in the wall, but I’ll post some pics here in case it helps someone else.

 

[kr236rk]

Are the light trap boxes necessary with the black tubing having two 90° bends anyway? Especially if you only deal with paper and can do film stuff without ventilation?

The light seeps in around the edges of the wooden guttering, it does not come down the tubing. I could seal all round the guttering, but what's the point? There's enough blackout for me to handle reversal film for re-exposure to an electric light, & safely back into the developing tank again, if I need to do that in daylight hours.

 

[kr236rk]

Looks very neat. Do you not get a lot of noise in those narrow pipes? My pipes are the full 10cm and direct through the wall (no bends). Light trapping is done by covers over the fans, attached by magnets. I realise this won’t help you, @kr236rk, since you can’t bore holes in the wall, but I’ll post some pics here in case it helps someone else.
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That is very nice work!

The fans are pretty mild - but the hum they make is not an issue. They are the same fans people use as extractor fans in shower rooms, and so forth.

 

[kr236rk]

Enlarger - was moth-balled for 9 years. Lights on = okay

 

[snusmumriken]

Looking great!

 

[kr236rk]

Looking great!

Thanks I step at a time!

 

[warpath]

To take care of condensation/moisture, a dehumidifier can work. I placed a little one in a small room and works great. It only cost me like $30 bucks on amazon.

 

[Sirius Glass]

To take care of condensation/moisture, a dehumidifier can work. I placed a little one in a small room and works great. It only cost me like $30 bucks on amazon.

Welcome to APUG Photrio!!​

 

[kr236rk]

To take care of condensation/moisture, a dehumidifier can work. I placed a little one in a small room and works great. It only cost me like $30 bucks on amazon.

Not had a problem with moisture.

Am missing the days, though, when you could just pop out & buy developing chemistry & papers, will all have to be ordered online now

 

[RalphLambrecht]

Hi,

Hey, there are new filmstocks!

I still have a darkroom-blind bathroom, but no ventilation.

So I just have to put in some DIY ventilation fans, to get my darkroom up & running again

- to take advantage of the new filmstocks!

Who would have thought that 'wet' processing was on the come-back?

Any ideas for ventilation would be very welcome - thank you!

KR

please see the attached article to find my effort to make ventilation airtight!

 

[kr236rk]

please see the attached article to find my effort to make ventilation airtight!

Nice wish i had a set of taps like that!