Yet another failed idea

Well again I have found the answer to creating a chiller using air power has futher been deemed out of reach. I will save everyone with the details of the trials but bottom line is I could not cool water below room temp using only sub-zero co2. My next attempt will be using only water but for that the whole concept I had in mind may not work. Oh well at least I have a few more months before I actually need my prototype to work. Anyone know how long dry ice lasts in a cooler?

When I worked at a grocery store, we used to get certain shipments in for the meat/deli department. In the foam containers they had dry ice to keep the contents cool. Now shipping up north from the major city centers in the south would take about 2 days, 3 at the most. There was always alot of dry ice left over once the product got to us. I wish I could be more help

well that helps. I am going to have to figure out some serious chem to make some of this stuff work. My idea is to make a chiller for under 23 bucks. So far my prototype needs to be much simpler and more hands off.

Good luck, all my homemade inventions and prototypes always junk out on me. What are you keeping Cryptobranchid?

I was wondering the same thing? Unless you are trying to breed cold tempered caudates, a chiller seems overkill especially in your area. I live in the Southeast where we have heatwaves in the 90's. Even in this area, I have found basements or sub-basements are the most effective in temperature control. Even rooms that can be isolated off from central heating in the winter, while allowed central a/c in the summer are effective as well. Rooms with south facing windows seem to be warmer and should also be avoided. It seems keepers work with what they have and can keep caudates that best fit their temperature ranges.
I have not tried it, but the cooler idea that used an ice chest with tubing and small pump, would be the most economical.
All in all, we sometimes mistakenly try to keep setups too cool for the common kept caudates in the field. One keeper once said, "you may find Notopthalmus in ice covered ponds in the winter, but it does not mean we should duplicate this in captivity." Environments in captivity will have limitations compared to the natural habitat even with our best efforts. That is why cold tempered stream dwellers like Cryptobranchid present many challenges for captive care for the everyday hobiest. The best environment I could provide for a Cryptobranchid is to leave it in the stream of their natural environment.

Right now the chillers I am working on are for wildtype axies and p.waltl. Last summer my C.o tank was running 80+ and that was with icepacks and all. My taricha would lay around on icepacks in his tank too, so I got lucky with him. The main issue is this year I am using alot more water and I know the time will come that I have to figure out how to keep 8 gallons or more cool when I am not around. I think I have some good blueprints but in all I assume I will end up spending some serious cash to get things off the ground.

Jeff,

I don't know if this will help, but I do have a few suggestions that could aid in your design.

First off, a cheap chiller is a rare thing. Ones that are built on the cheap often require so much upkeep that they are hardly worth the effort.

That being said: I have a few suggestions based on my industry experience with cooling.

First, you can use just air to get it below room temp. If you can run the aquarium water through a heat exchanger (perhaps an radiator from an ATV or something) and mist water on the outside of the radiator, you will achieve this. In order to evaporate, energy is needed to change phase from a liquid to a gas. As the water on the outside of the cooler evaporates, it takes energy in the form of heat from the water within the radiator. At best this may only buy you 5 to 8 degrees below ambient.

Second, look into draft boxes. They are basically a setup that runs draft beer through a cooler filled with ice. This might help you out if you can control flow, etc. I would be concerned about delivering too much cooled liquid into the tank at once. Perhaps a bypass valve to mix chilled/unchilled water together at the outlet of the box?

Also finally, keep in mind that any pump will add heat to your system. The more powerful the pump or the "harder" the pump has to work, the more heat you enter into your system. I would suggest placing the pump before the chiller for this reason.

I'm totally a do-it-yourselfer so I know the appeal of projects all to well. When all is said and done though, you might just want to shell out the $400 for a chiller module.

Best of luck!

Oh, and for the record, no idea can fail as long as you've learned something.

Marcus

You must be keeping your setups in unheated/un-airconditioned room or garage if your temps get up to the 80's in the summer. That would be a difficult undertaking. I still think if you tweaked the idea of the tubing/pump through a cooler of ice packs may be your cheapest alternative. Marcus brings up some good points of not having too much cold water introduced. You can adjust this by adjusting the length of coiled rubber tubing in the cooler and the flow of the pump. You could probably run several systems via one ice chest. If each pump had a sponge type filter over the intake, this could act as a biofilter.

Marcus, you've posted some good information, but I'm puzzling over this sentence:

<blockquote><hr size=0><!-quote-!><font size=1>Marcus wrote on Thursday, 23 February, 2006 - 05:21 :</font>

"First, you can use just air to get it below room temp. "<!-/quote-!><hr size=0></blockquote> Did you mean "cannot"?

I'm intrigued by the suggestions you've posted here and elsewhere about equipment used for brewing (draft boxes and temperature controllers). This is an area of equipment I had never considered before, but might have some handy applications for newts.