View Full Version : Working in a warm (very warm) darkroom

24-Mar-2018, 18:51
Now that the warmer weather is beginning to return to the desert southwest, I'm thinking that my silver printing days will end soon for the season. I've only had my darkroom setup for a few years now in my new home, but in past years I've relegated myself to printing pt/pd during the hot weather or not printing at all. I never liked the idea of not being able to work for a considerable part of the year. How long are we talking? My darkroom runs about 80 - 84F for, at least, 6 months of the year. Anyway, I'm curious if others face this same issue and what, if anything, has been done to continue working; specifically, silver printing.

Thank you.

HT Finley
24-Mar-2018, 19:05
In the southeast it gets hot, sticky, and totally miserable. But you just have to deal with it. When you're in your hot darkroom, be glad you're not on a work crew tarring a black roof or on bucket truck fixing the power lines so somebody can sit next to the air conditioner eating twinkies. There's guys that do that every day.

Michael Clark
24-Mar-2018, 22:11
I,am in southern California where the summers are hot but not to humid, I have a zone VI temperature compensating timer for printing which helps, but after the water temp rises above 80 deg. F I just print very early in the morning or print just really dense dark negs.Right now the dark room is in a extra bathroom in the house. With Roll film I can chill the chems down to a stable 75 F. with out to much of a problem with ice baths, with sheet film it is much harder.

Doremus Scudder
25-Mar-2018, 01:23
80F with little humidity is not all that bad to work in. I do it all the time. Chemical temperature is not really an issue here either; prints just develop faster. Ideal is a Zone VI compensating developing timer that will adjust its "seconds" to be faster when the temperature is higher, but it's not absolutely necessary. I'd just note the ambient temperature in my printing record (e.g., 2.5 min. @ 82F or the like) so I could make some kind of compensation if I wanted to reprint at a lower temperature.

If personal comfort is the issue then a small air-conditioning unit might be the ticket.



25-Mar-2018, 03:42
When I lived in Florida, my water temperature out of the tap was a consistent 80F 10 months out of the year. Air temperature was at least 10 degrees higher with 90% humidity. I adjusted dilutions and times to deal with it and got consistent results.

John Layton
25-Mar-2018, 04:37
Had a "hot in the summer" darkroom a few years ago (no longer the case - such a relief!)...but was able to incorporate a small window-mount AC unit, with some extra black tape/blackout cloth baffling, but it worked great! My vent fan was mounted in an insulated "black out" panel above the AC unit - and I had no problems with vented air getting sucked back in, as the air disbursement/velocities were very different. At any rate...the top vent panel was on a separate hinge, mounted to an auxiliary flange I'd created for the window frame, which allowed me to swing it out of the way to let in some light and basically have half of a functioning window when needed/wanted.

hendrik faure
25-Mar-2018, 05:25
"my silver printing days will end..."

high level complaint
(looking out my window)

two weeks ago my darkroom was 15 degree Fahrenheit.
I depose some chemistry in the refrigerator to protect from freezing
Meanwhile dirty wet weather begins, often for months

25-Mar-2018, 09:02
Thank you all for your responses. To be clear, I'm not concerned about my own comfort; the warmer darkroom temps really don't bother me as it is very dry here. I was interested to hear what folk's experience was developing prints in chemistry around 80F and it sounds as if it's not problem. As I have a Zone VI Compensating Timer, I'm planning to print right through the summer this year and see how it goes. It's nice to know that it's nothing to worry about...

@John Layton, yeah, back when I lived in Vermont a "warm darkroom" was never an issue; mostly I had to figure out how to keep working through the winter months because the ambient darkroom temp could be around 50F and the in-coming water line could freeze depending on the outside temp and wind. I miss Vermont a LOT, but I don't miss those long, cold winters. Oh, and mounting an A/C unit in my darkroom is not an option due to Home Owner Association rules.

Gary Beasley
25-Mar-2018, 10:26
The good “portable” ac units have two separate ducts that can go into a window or two to cool a room if you happen to have enough room for it and doesnt look like a window ac from the outside. If it was cleverly disguised do you think the HOA would get thier panties in a wad over that?

25-Mar-2018, 11:08
The good “portable” ac units have two separate ducts that can go into a window or two to cool a room if you happen to have enough room for it and doesnt look like a window ac from the outside. If it was cleverly disguised do you think the HOA would get thier panties in a wad over that?

Thanks for the suggestion, Gary. Yep, I looked into those units a couple years ago, but there is only one large window in the darkroom that has two panes sliding horizontally to open/close making it difficult, IMO, to mount the required hoses. Not impossible, but security of the window would be a consideration, too. I doubt the HOA would have a coronary because the setup in the window probably wouldn't be visible due to sunscreens; these screens are difficult to see through. All that said, I'm going to keep that option open.

Gary Beasley
25-Mar-2018, 15:28
If this darkroom is a dedicated feature you might use something like dryer vents directly through the wall.

Keith Fleming
25-Mar-2018, 18:36
Another option is a ductless heat pump in the darkroom. Heat pumps also act as air conditioners in warm weather, and they are rather quiet. However, that does not solve the issue of venting chemical fumes--but there can be workarounds to handle that problem.


Maris Rusis
25-Mar-2018, 19:53
I live in a hot climate so I chose to build my darkroom to include a small (2.5kw) split system inverter air-conditioner. Now I work at 24C all year round and the darkroom is the place to be when the inevitable heatwaves hit. The air-con (Panasonic) removes dust and smells with special filters and it has an electronic "zapper" for volatile organics.

The other key decision was to eliminate forced air exchange with the outside world. Conditioned air costs money and blowing it out into the garden made no sense.

What about the chemicals? I use odourless developers - no smells, no fumes; odourless stop bath - no smells, no fumes; and odourless fixer - no smells, no fumes. The air in the darkroom feels fresh, clean, and cool all day.

What about the cost? About $2500 installed but I told myself I'm spending several hundred hours a year in the darkroom and I, er, deserve it. And I reckon I print better when comfortable and not itching to finish early and get out of the place.

John Kasaian
25-Mar-2018, 20:05
Replace the appliance bulb in a small fridge with a safelight. Cold beer saves the day!

DG 3313
25-Mar-2018, 20:11
I live in central Calif. and two of my dark rooms were in the garage. When I framed the enclosures in one corner of the garage, I also installed a window type AC unit by the door. For air balance I added louver vents made for darkroom use (light tight). The vents let the AC unit do its thing and vent conditioned air out of the room.


HT Finley
25-Mar-2018, 21:22
I am not not by nature one prone to challenge rules. Rules are rules and I mostly abide them, even when I deem them absurd. HOA's are something that is registered by the neighborhood developer before construction of the first house was laid. Because of that, these rules stand forever. There's always been HOA's I suppose, but now they proliferate. I'm a rea estate agent. My question is, what about "variances"? I've taken a bunch of real estate courses, and know all about variances. but not one thing I've heard about a "variance" in an HOA. That said, if I were an ardent photographer in a place like the desert southwest US, I believe I'd throw caution to the wind and put a window unit in my home darkroom. It's not liek you were putting in a Ham rig and screwing up everuone's TV reception, or putting an "88 Ford up on blocks in the front yard, and an upholstered sofa on the front porch. For Pete's sake, I'd put in my window unit, do my photography, and let the HOA president come after me whenever. What are they going to do? Make you leave your house, and have it repossessed by the HOA? Somehow, I don't think they can do that. Enjoy your darkroom. Damn the torpedoes. HOA's just don't want you to redneck up the neighborhood. They're not to stop you from living.

21-Apr-2018, 20:24
I realize this is an older thread. That said, the biggest problem I have in PHX is the wash for fiber printing. The tap puts out water in the 80-95 degree range and it really softens the emulsion. I had the cold water line moved inside and think that will help some.

HT Finley
21-Apr-2018, 21:21
Wow 80-95 is some seriously warm water for FB especially. You're right. In the southeast (NC) it might get 82 or so in the hottest season, and I don't like it at all for washing film and paper. You inspired an idea. I don't know anything about your darkroom space. But let's say it was big enough for something like an ordinary Frigidaire or Hotpoint fridge full of cubitainers or water bottles plumbed in series with the inline water. That fridge would hold a good bit of water like that. now the question is how high you could make the interior temp of the refrigerator. Well.. at least I'm thinking. May be a dumb idea.

21-Apr-2018, 21:39
I have a 5 gallon pail with a copper coil that I fill with ice and run wash water thru but it can't handle any sot of volume. I have a chiller that powers up when plugged in but I'll need to run a 220 line and then hope it will work as its supposed to. Since most days I want to stay married, lm temporarily not printing from mid July thru mid October. I could probably print color. Hadn't thought about it before. Thanks.

Jim Andrada
25-Apr-2018, 16:37
Re HOA's - they can order you to remove stuff not allowed in the CC&R's and if you don't do it they can often place a lien on your property for the cost of removal of the offending stuff. Which can play Hell with your financing.

I usually switch to MF in the summer and run Ilford XP2 C-41. Or use a lot of ice in the Jobo.

25-Apr-2018, 17:14
There's always been HOA's I suppose, but now they proliferate. .

I'm so glad we don't have those anywhere near where I live. If someone were to try & tell me not to hang a deer from a tree in my yard when I cut it up, I'd tell them to kiss my grits. Here, your property is your property. As for hot dark rooms, to keep your clothes from getting all wet & sweaty couldn't you just work in the nude? If it's dark, no one would know.

Kent in SD

Pere Casals
26-Apr-2018, 03:45
A solution is Xtol 1:1.

You just need some water from refigerator at say 45F. If you have stock developer at 86 instead 68 this is 18 too much. So you mix the stock stuff with water at 68-18 = 50F, when you mix stock at 86F with water at 50 you obtain 1:1 at 68F. So if you make the 1:1 dilution just before developing you can nail the temperature.

Later, if you have not exactly 68F then you can use the general time correction graph vs temperature that's in ilford datasheets.

Another choice is buying a "wine enthusiast refrigerator" for example "iGloo 12-Bottle Wine Cooler with Curved Glass Door" to have all chem and some water at 20C, or 19C to have 1C margin. Those kind of devices can be found even for $60, new.

26-Apr-2018, 05:58
Not really sure about your space but two ways I have seen might work.
The already suggested portable room type air conditioner. You can filter the air intake so what is generated is pretty clean cool air to work in. The window being open - but not really visible from the street can be solved with good black out curtains or a cut out piece to place in it for light blocking.

On water temperatures. The farmhouse I live in has two water heaters. One is a non-working holding tank(insulation removed) while the other is a working water heater with less capacity. Water temperatures coming in during winter are in the high 30's and summer high 40's to low 50's. The big 80 gallon tank fills with the cold water and it gradually warms to room temperature. Then it flows into the working water heater. Checking cost for use doing this saves a lot of dollars as incoming water is generally at least 60 degrees so the heater does not have to work as hard to get it up to a usable heat level. Yes, the extra tank takes up space. It also gives us a good reservoir of water in case power goes out for awhile. In the winter that is a lot nicer than going out near the barn and using the hand pump to fill containers.

If you check around there are probably some shops or stores that can help you solve the problems so you can work in comfort all summer. Controlled conditions have to be better for your prints as well.

Pere Casals
26-Apr-2018, 06:49
You can filter the air intake so what is generated is pretty clean cool air to work in.

Many portable air conditiones do include a foam filter that removes most of dust, this is good, even it can be started when no cooling is needed, in vent mode, to remove dust, anyway a good job for dust is only made with an HEPA air purifier.

26-Apr-2018, 10:03
Another dust solution is to have plastic sheeting or covering on one area and rub it with a piece or wool every now and then. The static charge attracts dust in the air. You wipe it down later with a damp cloth to clean it. Simple and effective.

26-Apr-2018, 11:02
Just wanted to thank everyone, again, for all the great suggestions!

26-Apr-2018, 11:34
I don't understand the issue, you get an air conditioner and a chiller. Not cheap, but it works. I have a central air/heat unit that cools the larger space where the darkroom is located. It has an inlet duct into the darkroom which has a filtered register on the inlet side instead or a regular AC supply register. I put an AC filter in there, and 2 1" filters on the Central A/C plenum, so the air travels through 3 filters to enter the darkroom. There is a filtered louver for make up air, either exhaust, or AC air in. Keeps it at a confy 68 Deg F. year-round, and with a 32 gph chiller for when the water gets warm you can get 68 Deg water. It's pretty well documented in this forum. Right now the water comes in just below 68 deg at night, so I don't need to turn the chiller on; the water just flows through the chiller piping. There is a 10 gal water heater in the room and I use an Intellifaucet K250 for temperature regulation. Not cheap but it works and saves a lot on perspiration and ruined film! I do have a wine cooler which is used to keep wine, and beer cool! Never sees darkroom duty. L


Dan O'Farrell
26-Apr-2018, 11:50
Well, right now it's 8C (not sure what that is in Liberian/U.S. measurements) and I'd sure like a bit of warmth in my darkroom without paying for it.
In the Dog Days of Summer, we suffer under 30C with high humidity, but the darkroom ( in the basement) stays at maybe 16C , and we never use
water straight from the tap ( FAR too cold).

26-Apr-2018, 12:46
Allow me to translate, 84Deg F is 28.8 C which is about what temperature the water comes in at at night during the summer in New Orleans. 8C is 46 Deg F, which I don't think our tap water has ever hit! You would surely need a sweater in a 16 C darkroom (60 F), but we don't all live in the frigid North, besides it's much easier and cheaper to warm than to cool!