How to Heat Up a Darkroom

slackercrurster · Dec 3, 2018

I used to have my darkroom in my mom's kitchen or bathroom and didn't have a problem. Later I got an unheated garage with water and electric. In L.A. you could get them back in the day for $75 a month...with utilities! Now people in L.A. would gladly live in the garage for $1,000 a month!

I used an electric heater that blasted radiant heat with no fan. It would just glow red and heat and I put it right near me. (I put some bricks on top of the heater to get hot so they would help a little.) I just worked in one corner, I didn't have to heat the whole place. Although L.A. was not that cold, I never would get room temp to 68 in the winter. (or burning hot summer)

I also used a small propane heater with 20 pound tank in an unheated place I lived in. The hard part was cooling things in the summer. In L.A. the garage would get to near 100 degrees. I had to carry in ice to use in water jackets to get the tank temp down to useable. Hot weather was worse than cold weather L.A.

I had a small compressor to blow by negs off. Never had a big dust problem, so don't think a heater with a fan would be a big deal. Back in the 60s / 70s, electric heaters did not have fans. They were not energy efficient and just made coils glow red. If you can't get the darkroom up to temp, just get it close and use a hot / cold water bath jacket.

That was what we used in the shops for nitrogen burst processing.

https://danieldteolijrarchivalcolle...it-back-in-the-day-nitrogen-burst-processing/

Or get an old Kodak Master Darkroom Dataguide. It has a computer for various developing temps...

Don't make a big GD deal over 68, just get the film processed.

removed account4 · Dec 4, 2018

Doc W said:
Any experiences with this?

Doc W
you gotta eat some lentils, peas, garbonzo, kidney, red, baked-navy and other types of beans
but you might have to open a window after a while ...
id be careful with heaters that emit CO or might knock over and start a fire

Doc W · Dec 4, 2018

jnanian said:
Doc W
you gotta eat some lentils, peas, garbonzo, kidney, red, baked-navy and other types of beans
but you might have to open a window after a while ...
id be careful with heaters that emit CO or might knock over and start a fire

I think that should all that gas ignite, it would definitely fog my paper.

Doc W · Dec 4, 2018

Mainecoonmaniac said:
I'm thinking out of the box. How about do "Seasonal" printing? Print silver gelatin during the warm months. On the colder months, do alt processes that don't require a separate dark room but could be done inside the house? Cyanotypes and salt prints could be done in a warm laundry room or bathroom.

Not a bad suggestion. I get the temperature problem at both ends of the scale, btw. In August and early September, the ground water is too warm for my Jobo. I can adjust development time, but only so much, so I put small freezer packs in the end of the water trough and it seems to hold the temperature quite nicely. My darkroom almost never gets really, really warm (maybe high 70s, low 80s F) although it can get quite humid. So I can develop negatives all year with my Jobo because it will keep the temperature of the water bath constant, even if the room is cold. But I shoot less in the winter anyway.

Prints are the real problem. The temperature varies so much, even during a session some times, and that can change development time.

Sirius Glass · Dec 4, 2018

Doc W said:
I think that should all that gas ignite, it would definitely fog my paper.

It would fogged the eyes too!

DREW WILEY · Dec 6, 2018

Convection heaters do not use coils or hot strips. They work like a radiator. You have to turn them on a bit in advance; but they heat surrounding air, are not even hot or hazardous to the touch, and continue to emit heat well after they are turned off. I find them excellent and highly cost efficient in a small darkroom space, though mine is well insulated, and in fact quite a bit
larger than most personal darkrooms. Let me repeat the word, insulation. Forced air is voodoo just looking for trouble with dust and static, even with filtration. But when I'm drymounting in an adjacent room, the mounting press itself is all the heat I need.

Michael Firstlight · Dec 6, 2018

My Darkroom in the 70's was in my parents house up in the attic. It was pretty cool most of the time, but it heated up fast when I was in HS and my girlfriend would come over and we'd see what developed

CMoore · Dec 6, 2018

Michael Firstlight said:
My Darkroom in the 70's was in my parents house up in the attic. It was pretty cool most of the time, but it heated up fast when I was in HS and my girlfriend would come over and we'd see what developed

Loose Gravel · Dec 14, 2018

My darkroom is 9 by 12 ft with 7.5 ft ceiling. Sheetrock covers the walls and ceiling, all insulated with fiberglass. The darkroom is separate from the house, so all the heat is what I make in the DR. Floor is concrete slab. In the winter, it is not unusual to begin at 13C. I start the 5 gallon electric water heater and the 1500W electric fan driven space heater about an hour before showtime. It works fine. The gallon jugs of chemistry need to be warmed a bit before I start. I do this with warm water baths, etc. All that said, even when warm in the DR, it was cold because of the floor. Concrete is a terrible heatsink with much thermal mass. I've now insulated the floor with a layer of cork that I ordered online. Over this I laid real linoleum. Still not perfect, but comfortable. Wool socks are welcome.

Of course, if you have a lot of unneeded thermal mass, such as a 55 gallon drum of fix or something, remove it from your space unless you are going to keep the DR the same temp all the time, 24/7, forever. Then it doesn't matter.

I do have a ventilation fan, but don't use it much. I use chemicals that aren't particularly volatile. No stop bath or stinky fix. I keep the door closed when not in use to reduce dust (and keep the dark in) and I clean floors and dust occasionally as needed. I have a small fan, Vornado, to move the farts around. YMMV.

snusmumriken · Apr 19, 2022

This will be an impossible suggestion if your darkroom is already established, but insulation is arguably your best friend.

My darkroom (similar size to yours) is a stand-alone shed (i.e. 7 faces exposed to cold, allowing 2 for the pitched roof), but each face (including the floor) consists of 2 inches of foil-clad foam insulation sandwiched between boards, with an extra 6mm layer of silver bubble insulation included for good measure, and wooden cladding outside. I leave a 700W oil-filled electric heater switched on at its lowest thermostat setting. Because of the insulation, the shed cools (and heats) very slowly so the heater spends little time drawing current, and the temperature stays between 16 and 22 C throughout the year. Without any internal heat source, but with the insulation, I suspect it would be <10 C for 8 months of the year here in the UK. I have fitted 4-inch inward and outward ventilation fans (with light traps and dust filters); when I'm working in the darkroom I switch both fans on for just a few minutes once in a while to change the air without much impact on the temperature. (The outward fan is also humidity controlled, but this rarely causes it to operate.)

Maris · Apr 21, 2022

The cheapest and most efficient way to turn electricity into heat is to run a reverse cycle air-conditioner in the heating mode. Resistive heating is always 100% efficient but the heat pump technology of reverse cycle air-con can approach 500% efficiency. The only stress on the system is on those days when the outside temperature is way too low; think -15C or less.
My darkroom has such a system and for most of the year it runs in cooling mode but for a few days in winter the cheap heat is most pleasant. And I keep the filters in good condition so there's no dust.
The ski lodge I've been to in winter (it's called Pygym Possum after the tiny animal that hibernates under the snow nearby) heats all its big communal spaces exclusively by continuous reverse cycle air-con. A constant 19C is very nice while blizzards rage outside.

Mainecoonmaniac · Apr 21, 2022

Heat pumps are pretty efficient. Our natural gas bill keeps going up. I’m toying with it idea of installing one when the gas furnace dies. I’d also like to get solar panels and get off the grid completely.

JonyWest · May 2, 2022

hmm, heat pumps... thanks for the advice Mainecoonmaniac

Paul Howell · May 2, 2022

Here in the Desert Southwest, the low desert, heat pumps are the most common form of heating and cooling. I keep my darkroom in a converted double bath at 70degrees year round.

eli griggs · Jul 30, 2022

Doc W said:
My basement darkroom is about 10x15 ft and it is cold in the winter. VERY cold. Some days it might be less than 10C (50F) The basement is a decent temperature but I didn't include heating in the darkroom because I was worried about dust. However, now it is time to warm up that dungeon.

I have tried two types of space heaters: heater with a fan and a radiator type heater (the kind filled with oil). The fan heater gets it up to temperature, but it is a fan heater, blowing all over the place. The oil radiator just can't seem to get it up high enough.

The heating in the house, including the basement, is forced air. I was thinking of adding the darkroom to the heating system (hot air in, cold return) but I am worried about dust again. I talked to one heating contractor and he said that a hepafilter system would cost over a grand. Do I need that much filtration or can I use something more affordable?

Any experiences with this?

You might try lining the walls with small, flat hay bails and cover these with mold resistant stain blocking painted wall boards.

Making a series of light, 2x4" frames, extended just far enough from the walls to hold the bails would be simple enough and once contained behind the wall board, dust, dry straw nails should keep your basement darkroom at about 62°f, especially if you use aluminum faced foam boards for celling insolation.

If the floor is concrete and dry, a low, raised, 3/4" or 5/8" exterior plywood floor 2" minimum, should add to your comfort.

By using smaller or 'thinner' nails, you'll loose less floor space, but should have an 8'x13' space that the oil radiator heater will easily make a warm work space.

IMO.

PS: By the way, if I ever build an outdoor storage/studio building, this is the type insulation I plan to design space for, for all seasons, but with full sized hay bails, just double check locally if you will need a plastic barrier between celery walls and straw nails.

Sirius Glass · Jul 30, 2022

One could heat the darkroom up by asking a group of photographers over and starting a film versus digital argument.

Pieter12 · Jul 30, 2022

Mainecoonmaniac said:
Heat pumps are pretty efficient. Our natural gas bill keeps going up. I’m toying with it idea of installing one when the gas furnace dies. I’d also like to get solar panels and get off the grid completely.

Depending on where you live, it may be tougher and more expensive to get off the grid than you might imagine. https://www.wired.com/story/home-solar-power-and-energy-resilience/

gone · Jul 30, 2022

I'd just use the best method that costs the least.

Dust was something that I was unnecessarily concerned about in my first darkroom (kitchen type). The only place that dust might be a problem is where the neg is in the enlarger and when the prints are drying. Otherwise, taking the paper out of the bag doesn't expose it to any dust that would stick, and after it's exposed, it's sitting in either a chemical or water bath until it's time to dry things.

We had a place w/ a heat pump, and it struggled cooling and heating our place. All of this depends on your place and where you live of course, and utility rates are all over the place.

CMoore · Jul 30, 2022

Is a Mini-Split an option for you.?

Michael Firstlight · Aug 2, 2022

CMoore said:
Is a Mini-Split an option for you.?

I agree about a mini-split being a wonderful option as long as there's a way to install the unit properly. I installed a 1-ton Mitsubishi mini-split in my 22x24 foot garage here in the SW NC mountains that I use as a portrait studio. Before the mini-split, the garage got searing hot in the summer and freezing cold in the winter. With the mini-split, I have no trouble maintaining a constant 68-72 temp year round. Of course, I did insulate the walls and ceiling as well, but the doors, while stock insulated, are still stock garage doors.

Mike

B+WFriend · Aug 2, 2022

I have similar situation, and my solution is to warm all my chemistry in water baths and put on an extra sweater and have a cup of strong tea. No dust problems.

Craig · Aug 9, 2022

Heat pumps don't work in the winter temperatures experienced in Ottawa. The easiest and cheapest thing to do is add a duct from the existing furnace.

ags2mikon · Aug 9, 2022

I have installed some of these. https://www.instructables.com/Chinese-Diesel-Heater-Workshop-Install/ 2 of them are in my motorhome and 1 is in a small room I use for my ham radio shack. This year I will be putting one in the darkroom to supplement my baseboard electric. The ones in the motorhome have been trouble free for 4 years now the other one was just installed last year.

How to Heat Up a Darkroom

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