Darkroom Dehumidifiers

[jars121]

G'day everyone,

My makeshift darkroom is situated in the basement, which can often become quite damp after heavy rains. I'm worried about the high level of humidity effecting stored paper and film, among other things (scanners/computer/etc).

I'm looking at getting a dehumidifier, such as this one.

Has anyone had any experience with units of this type? Are they worth the investment for particularly damp rooms?

Thanks!

[jp]

I've got a portable "Soleus" http://www.amazon.com/gp/product/B00009RAVO ; sort of the same style in my garage. It's been doing fine for 2 years, keeping a 1200sf place dehumidified. I would not store photos and photo equipment in a place apt to get very damp.

[jars121]

I've got a portable "Soleus" http://www.amazon.com/gp/product/B00009RAVO ; sort of the same style in my garage. It's been doing fine for 2 years, keeping a 1200sf place dehumidified. I would not store photos and photo equipment in a place apt to get very damp.

Thanks for that. Unfortunately this is the only room in the house I can use. It's not usually too damp, just after heavy rains. I'm hoping that a dehumidifier will be able to maintain a normal humidity.

[Sevo]

If you know what they can and can't do, they can come in handy. But the common household size air driers (with nominal 20l/day specs) will cope with just about 2-3l of water per day at normal room temperature if they are to keep the air at 55-60% rel. humidity (the specs give far more generous figures for something like 95% rel. humidity at 30°C, but these are target values nobody will aspire to in a lab setting). You can bump up device size (or type) and the corresponding air throughput to collect more water, but then you will predictably run into dust and heat issues.

Mine worked well enough to contain the evaporated moisture of an ATL and a CPE-2 in a unventilated small room in the 2nd level of a dry office building - but given that it went through a 5l tank every other day, I don't believe that it would have packed additional humidity from a wet wall along with it, so they aren't really a substitute for a proper room.

[cowanw]

My darkroom is in my basement and we have to run dehumidifiers from May to September. The darkroom is simpler as it is a much more sealed room and a 24 pint dehumidifier does a fine job. There are also humidifiers thst will pump your water into the sink so they can run unattended in the days you are not in there.
the ebay listing is the smallest at 2.2 litres look for a larger one, like 12 liters

[Worker 11811]

My darkroom is in my basement. It's about 12' x 16'. It used to be the workshop. I never needed a workshop in the basement so it became a "junk room." After a while, I cleaned it out and decided that I ''needed" a darkroom so, here I am.

The basement is relatively dry but, like the OP, it gets damp after it rains. That's not the crux of the problem. It is because the basement takes longer to dry out. That's what the dehumidifier helps with.

I just use a basic household dehumidifier and I make sure the darkroom door is closed when I have it on so as to minimize the damp air that rolls in.

One trick I use is to hang a strip of fiber based photo paper on the wall, fastened only by one thumb tack at the corner. That piece of paper will curl or uncurl in reaction to the humidity level. If the paper flattens out, the humidity is too high. If the paper starts to curl, the humidity is low.

I run the dehumidifier until the strip starts to curl away from the wall. If it curls into a letter "J" there's not enough humidity. If it lays flat against the wall, there's too much. I shoot for making the bottom half curve gently away from the wall... Just right!

[William Whitaker]

I would suggest that if you buy a dehumidifier, you get a name-brand unit from a reputable local dealer (not Ebay) so that it can be returned for repair. I have a Sears Kenmore unit which worked well for a year, then stopped working. The problem was the control board. Sears repaired it for $100 (half again the purchase price) and it seems to work fine, at least for now. In the interim I purchased an LG from Home Depot. That one stopped working after two months. I've not had good luck with these things.

Where I am now I have a Soleus. It seems to work well. But it puts out an enormous amount of heat. And when I need it the most is during the warm months, so that's inconvenient. But it does remove humidity well.

If your basement is not heated, you should consider a low-temperature unit. These are designed to work at lower ambient temperatures which would cause a normal dehumidifier to freeze up.

And finally, if you own your own home and don't rent, consider a foundation drain to help keep water from entering the basement in the first place.

[ic-racer]

Since the 1980s I have gone through about 4 or 5 of the Sears Kenmore units. I have had all the experiences of failure, self-repair, repair under warranty, failure of warranty repair, free replacement and failure, etc.

The problem with those cheap units is that the when they fill them they crimp the fill line and it is a one-time thing. There is no fitting to re-charge the system. Add to that cheap electronics and lack of replacement parts and you have an appliance manufacturer's dream: programmed failure.

Now I use this one for both the darkroom and the entire basement. I considered a 'built-in' unit attached to the central heating/AC system, but from what I can tell, this one is just as good as a built-in unit and there is no installation cost. You plug it in and wheel it around just like those cheaper little ones. You do need a drain. That is no problem if one has gas heat. Most all gas heaters have a drain to collect the combustion byproduct water. I also have the schematic and parts list for it and confirmed that the parts for it are available from most HVAC parts supply dealers, in case it does break.





I also use Aprilair humidifier in the winter. That one is built-in for the whole house. Darkroom humidity today = 49%
I use this Taylor sling psychrometer to check the humidity. The nice thing about a psychrometer is that it does not drift or need re-calibration like a dial-hygrometer.

[jars121]

Thanks everyone for the great input, I'm going to try and fine a branded, reliable unit and see what sort of humidity control I can manage.

[WayneStevenson]

I use a brand-name one in my darkroom. Works great. I have to run it off and on throughout the spring and summer. But it's worth every penny I paid for it.