So i had this idea................

ok well here it is, i was thinking last night about salamanders (go figure) and i got this idea

i had a plan to solve a constant problem in caudate captive care...how to keep em cold. so here is my plan (complete with white board diagrams...)i have devised a DIY form of a chiller and total cost will be under 300$. here it is:



the plan is this:
get a small fridgerator and drill 2 large hole big enough to pass vinyl or silicone tubing through. if you would like to make the tubing removable-just put a smaller piece of pvc through the door and hook up to it on the inside and out. i know drilling through the door face will not interfere with any of the internal workings of the fridge(dont drill through the cooling unit!!). silicone these pieces into place to ensure they are airtight-to avoid cooling loss. now take the tubing -a minimum of 40 feet i feel and coil it about itself and bundle it up a bit so it can sit on the inside neatly(that way if you open the thing it will be easy to close.) if you so desire adding more footage and thus more coils will add more chilling power since more water will be in the fridge at one time.

the cooler you set your fridge the cooler the water will get. now close up the fridge and place it facing the tank-or at least off to the side-dont place the back(exhaust) to the tank as this will defeat some of the chilling power-remember fridges work by displacing heat-so for as much heat as they remove from the water the will place that much more in the air.hook up the two ends of the tubing on the outside to a canister filter-it is best to have the water go from the tank to the filter BEFORE it goes into the cooling set up since colder water drops more 'load'(dissolved and suspended material) and this way the tubes wont clog (im sure you will have to clean them out periodically anyways but a whole lot less). the beauty of this system (especially if you find there are no components on the side of the set up and can drill in from there and dont have to fight the door) is that it can support multiple set ups. a bigger fridge could have many such tubes set into it and each is an independent system-so no risk of contamination from one set up to another(from this at least).

so what do you all think?? am i a genius or.....??

Couldn't you just move to the UK?

Hi Paris,
There was some discussion on this on a differnt thread a couple of days ago.
This has been discussed to death in some reef keeper forums (and even some articles).
There are limitations of this set up. They are as follows,
1) the amount that the temperature can be lowered is limited by the difference in temperature between the enclosure and the desired temperature as well as the amount of water that needs to be cooled. (It usually is only sufficient to lower the temps slightly but this depends on the amount of water, and the difference between desired temp and actual temp)It works best on small systems that are close to the desired temperature.
2) the rate of water flow needs to be very slow to allow for the maximal heat exchange, this makes it hard on the pumps and makes the filter very inefficent. The filter should be on a different set up.
3) the pump should be before it enters the fridge as most of these pumps are water cooled and having after the fridge will just cause the water to warm up faster.
4) You really need to pack the fridge full of tubing to maximize the heat exchange.
5) the fridge needs to be as close to the tank as possible. (which means the heat from the fridge may adversely affect the tank.
6) It needs a couple of days between "adjustments" to the cooling level of the fridge to see where the temps are going to settle.
7) The larger the fridge the better the temperature exchange. The other problem is that most fridges are energy hogs.

I'm always interested in hearing how these set-ups work out but all of the stories I've read about usually got hung up with the above issues.

A good chiller while expensive can drop the temperatures as much as 30-40 degrees from ambient temperature depending on the size of the enclosure and the difference in the temperatures.

Ed

i guess i should read the other threads more....would a freezer be better? for more heat exchange im guessing smaller tubing. do those professional chillers have the ability to do more than 1 set up at a time? i problem i have with a/c units is when the power goes out they dont automatically restart and they have a bottom limit of 60F-its also says in the manual it is not to be used for animals (they show a pic of a fish tank).

Hi Paris,
It would be difficult to set up a chiller unit for more than one enclosure as you would have to plumb all of the systems together. I have not seen any information on using freezer units as a chiller, so I do not know how that would work.

The reference for the AC unit is that they should not have the coils adapted to chill aguariums or be in submerged. We use larger AC units (the ones you see in a walk in freezer) at work to temperature control whole rooms for amphibians.
I haven't had a problem with the home units restarting but I don't know if this is specific to different brands or models.
If you know someone who is good at wiring, the AC unit can have the thermostate replaced with a unit that reads lower than 60F and you can get the temp lower than 60F if you use an oversized unit as the larger unit should be able to handle the load.
Also with regards to the electic bill, when you have multiple enclosures it is much cheaper to chill a whole room as opposed to each cage seperately.
Ed

Good idea, but how about putting the whole tank in the fridge? One would have to cut out some windows though. Or maybe even better, getting a used one of those restaurant/store shelf/closet-like beverage chillers (with glass doors).

Great illustrations!
To build upon Ed's comments...
40ft of tubing would be way too much for an ordinary canister filter. This would definitely require a recirculation pump, a Mag drive pump would be ideal. Since you really only want clean water going through the tubes, you would want to draw off of a sump that is fed by the filter system (very common system in aquariums).

If I had newts and the $, I would DEFINITELY consider experimenting on your above plans. Luckily I have 6yrs HVAC and plumbing experience to help. Like Ed, I would also like to see someone's setup like this.

Hi Ralf,
I know some people that use the coolers with the built in peltier chillers to raise montane plants. They replace the lid with a glass pane and/or cut out the front wall and insert a glass or plexi glass pane. These systems seem to work pretty well for the plants and they report getting the temperatures down into the 50s for the plants.
Ed

Hi everybody,
I'll expose what I do for my Triturus, Salamandra and Ambystoma species.
The individuals I have are not too many nor too big, so they can stay during a certain part of the year in a normal fridge for offices that I got recently. I changed the fridge thermostat with one for homes, so that I got the possibility to drop the temp to 5°C or I can let it warm up to 30°C. Obviously I put the temp on 18°C during most of the year and let drop it to 5°C during winter period. But I have to confess something: I've had the fridge just for 1 month (before, I didn't have any caudate but one); during autumn and spring, I will let the animals out-doors in my balconies in bigger tanks, where they will be able to court and/or breed; the tanks in which they have to stay during summer are the same in which they will have to stay during winter, but there is a fact: during winter, it is really cold, so that the animals wouldn't need too much room to live; during summer, they will have to stay just a little bit tight...
Anyhow, I don't think they are going to suffer, and this is the unique way to keep this kind of animals here in Palermo, Italy, where the temps in summer reach even 40°C.

Best regards,
Fabrizio.

Old fridges work ok as cheap coolers.
But are you prepared for the condensation on the outside of the chilled enclosure which will drip all over the place and grow mold?

would copper tubing work better for heat exchange in the fridge?

Might work better but might also be toxic to plants and possibly animals depending on the water.

Small amounts of copper will leach into the water system so I would not recommend copper with amphibians and/or fish (although over time a layer of copper oxide will form reducing the amount of copper getting into the system (this why new homes can be a problem for fish). Also it may be difficult to form enough coils in the fridge.
Alan what was the temperature drop you were able to achieve with the fridge compared to the external temperature?

Ed

I really like those cartoon characters. Can I hock them for my soon (2005) to debut comic strip "Torosamama?"

Ed, I've never used a fridge myself, but I have fishkeeping friends who have, simply coiling 10-20 metres of plastic hosepipe inside the fridge for heat transfer. It's not terribly efficient, but since it runs constantly, it does work. The amount of cooling depends on the setup: ambient temperature, length of hose, etc. You can get a reasonable degree of control by adjusting the fridge thermostat. The reason I've never done it is partly space issues (wife complains about tanks, the idea of old fridges standing around is unthinkable), partly because of the condensation problem - if you drop the temperature by more than a couple of degrees, this becomes a real issue.

Has anyone had a good experience with the peletier chillers? How many degrees do they drop the temperature?
My previous research on them led me to believe they could lower the temp by only a few degrees.

Anyone ever consider using a wine chiller. They maintain temps in a range that is more of what we're looking for compared to regular refridgerators (low 50's to mid 60's). Home Depot has some nice glass fronted ones for $175. It would probably fit 3-4 plastic shoeboxes. Pros/cons??

My grandpa always discouraged the fridge-style chillers because, unlike an airconditioner, the compressor in a refridgerator was never designed for continuous use.

I've seen designs for cooling set-ups based on the heatexchangers you see used in high-performance computers, but these are admittedly for small enclosures.

It depends how much of a temperature drop you need. Me, I use a one-room window-mounted airconditioner. I figure, if I'm already using that much electricity, I should get to enjoy the temperature drop as much as my critters do.

right on!