Igloo thermo-electric cooler for chemical temperature control?

I know B&W processing can be very forgiving to temperature ranges but I'm using B&W processing as a step to disciplining myself for color processing. Temperature control is the only step in my B&W habits where things have to be improved in order to start processing color.

I've done a search and can't seem to find any posts here or elsewhere about using a thermo-electric cooler for maintaining a constant temperature for chemicals. At the moment I'm using a regular cooler and "Blue Ice" to cool 900ml Datatainers. I am constantly moving them from the cooler to a warm water bath to stabilize the temperature as best I can but it's tedious and isn't consistently stable enough for color processing.

Anyone using an electric cooler for their chemicals?

If your ambient room temperature is much over 38C then a cooler would make sense, if it is able to keep the temperature consistent. Bear in mind that the first developer is in the tank for only a couple of minutes, so an alternative might be an insulated drinks-box containing water bath, chemical-bottles and dev-tank, all at the appropriate temperature before starting processing. The temperature will not change during the critical fist developer, thereafter change will be minimal and could be controlled by a putting bottle of frozen water in and out of the insulated box. Using a similar method for warming the chemicals (rather than cooling them) is fairly trivial and works perfectly adequately here, so it should be fine the other way round too.

Edit: I just re-read your post about moving the containers from cool to warm and back again. Why are you doing that? Just set up an insulated bath at the right temperature, place the containers in it and allow the whole thing to get to the same temperature (with adjustment to the complete environment, not individual containers).

Temperature control is dependent upon the chemistry! Where the Kodak color darkroom guide from the mid-90's says, "A deviation of as little as ±0.25°F in a developer used for color processing can change the characteristics of your transparencies and negatives", if you look at the Arista kit from Freestyle, it has a table that seems quite analogous to B&W developer!


Part of the difference is due to the time precision that used to be needed, like 3min15 sec. specified in the Kodak instructions for C-41, vs. the 20.5 min specified for the Arista E-6 kit.

Consistency provides more control, as color shifts materialize when your controls are not consistent, and you cannot standardize things like color print filter value across multiple rolls of the same film due to color shift resultant from processing inconsistencies.

I think blue ice is the easiest, countered by a water drip line. Larger water jackets help. You can always buy an automated tempering box or thermoregulator, though it might take some patience finding one.

Electric cooler arrived. Plugged it in, put a 900ml beaker and three 900ml Datatainers in overnight. It certainly cools but its spring with overnight temps in the upper 40s, lower 50s. Higher temps.are forecast for next week so that will be the real test. There's no thermostat so it will be a matter of adjusting the lid height. Still, the potential for more consistant coolng than Blue Ice in a regular cooler is certainly there.