Pretty soon my troubles will go from needing to heat my developers to trying to keep them cool. Does anyone have any experience with aquarium chillers? I've been researching this for all of 10 minutes, but I found a relatively cheap type (they can run into the thousands for big ones) that looks small enough to mount in a large tray or tempering bath
but I have no idea how these work, or if they are even remotely feasible for this purpose.
If you're already doing something quasi automatic to heat (aquarium heater and submergable pump?) your tempering bath, why not just float some ice packs in it? The ice will keep it from getting above the heater set-point and the heater will keep it from going below.
These small units can be great, but:
In small aquaria there sometimes are problems with the waste heat that the filter system and light system gives off. This little gadget can fix this.
Note: Unit is designed for small aquaria only, with low cooling requirements. Product will not cool below room temperature.
But it is not a true heat pump, and -- as the caveat in the description says -- does not lower the temp below ambient room temperature.
I'm sorry, but I think you have to go for a bigger (and sadly, more expensive unit) like this one.
aquarium dude too -- MW
I've begun the same search. The IceProbe is a small semiconductor device (Peltier effect) with about 50 W of cooling power. How well that would work would depend entirely on the heat gains to your tempering bath. If you insulate the sides of your bath, cover it and have plenty of water in it you might be in with a chance. Given enough time a unit could also cool an insulated water storage container. With time, adequate insulation and thermal inertia a small cooling unit could work. They wouldn't be able to get uninsulated units (eg fishtanks) much below room temp because the heat gains through the walls would be too high. Stop those conductive heat gains and the temperature will come down.
Do you want me to do some approximate calcs?
"If you're already doing something quasi automatic to heat (aquarium heater and submergable pump?) your tempering bath, why not just float some ice packs in it? The ice will keep it from getting above the heater set-point and the heater will keep it from going below."
The ice packs may cool the water faster than the heater can warm it back up, so you would need to keep an eye on the temperature (and provide good mixing) so you can carefully regulate the addition of ice.
Yeah, you'd want to experiment with how much ice to use to keep the system in balance. Seems like something that you could do over the course of an afternoon while doing stuff around the house. Something like: put one pack in, turn everything on, come back in an hour to check temp. Add a pack, repeat.
Originally Posted by Helen B
FWIW, this is almost exactly what Jobo recommends.
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argg, damn that fine print....that one you linked to is discontinued (and too expensive). I could spend up to $250 if I have to. The ice cube idea is intriguing but sounds like it could be a hassle. I hate hassles. I'm so spoiled by my aquarium heater, which is absolutely hassle-free for winter work.
Originally Posted by Magnus W
More on the IceProbe.
Price with a controller to maintain 65F to 85F temperatures is about $165
Will pull 10 gallons of water in a typical aquarium down 6 to 8 degrees Fahrenheit below room temp. More with an insulated water container.
My present tempering bath is a LOT less than 10 gallons (Its an 11x14 tray with just enough water to cover the heater), though I will probably have to make a larger one in order to accomodate an Iceprobe or other chiller. I wonder if it will cool just a few gallons to more than <6 below room temperature. My darkroom probably exceeds 80 in the summer, and its not practical to A/C it.
In case you also wish to do some homebrew -you might check out willams brewing (there are other suppliers but that one comes to mind) and search for chillers and see if any of the pumps/heat exchangers/chillers might work. if not it might start another hobby -just in time for a global warming summer.
The IceProbe doesn't protrude far into the water bath. It needs a 1.25 inch hole to mount through a side wall, with the peltier junction and a fan on the outside. It should be able to cool less water more rapidly. If you poke around on the sites I linked to, you'll see two of the IceProbes cooling a larger volume of (apparently enhanced) water to 20F degrees below ambient in a home-brewing setup.