Refrigeration Question

[roscoedoh]

Sirs,

 

Allow me to explain my situation so you'll understand why I'm asking such an off the wall question.

 

Not only do I hunt and shoot guns, I am also an avid aquarium enthusiast. For all but one of the last fourteen years, I have had an aquarium up and running and I miss having one around. The reason I had to get rid of my aquarium last year is because back then I had just graduated from college and money was very tight and the electric rates had reached a point where I could no longer justify the expense of cooling my entire mobile home to keep the July-September temperature of my aquarium safe for fish. I tried shutting off the A/C and keeping a fan blowing over the tank, but that didn't work and the fish didn't make it.

 

However, I got a call from my buddy in Okinawa about two months ago who told me about his new keg-o-rator that he and his room mate built out of an old dorm fridge and some fittings. And that got me thinking about using a dorm fridge for an aquarium chiller. I live in a college town where small refrigerators are fairly easy to come by on the cheap. I am considering finding a small refrigerator (like the one below) and plumbing in a length of 1/2" plastic tubing so I could circulate water from the aquarium through the fridge and back into the tank. Anyone have any idea if something like this would work?

 

Thanks,

 

Jason

 

[donmarkey]

It should, how do you think a water dispenser on a fridge works. I have done it for a kegerator using a cooler full of ice and stainless steel tubing.

-Don

[cold shot]

how cold do you want the water? after it comes out of the fridge,i'd have a few coils surrounded air to reg. temp. hey man that is a coool idea as we have exotic fish at our house also. don't forget to regulate the temp cause you don't want to come home to find fish stickles. good luck! dave

[sphingta]

buy a line voltage thermostat with a remote bulb sensor. Drop the sensor into the tank. Run power for a small pump with your

hoseing through the side of the refrigarator. Inside the frig put swap over to soft copper tubing rolled into a coil. put that in a bowl of water for good heat transfer. You can use soft poly tubing on the outside. when the tank temp. gets to warm the thermostat will turn on and the pump will start. When the deadband of the thermostat is reached the unit will turn off. The best part is that the tubing and water bowl should not take up much room so you could keep soda or beer in the frig. also a small aquarium pump should draw very little power. the most expensive part likely will be the thermostat depending on how programmable you want to get.

[tinkerfive]

Jason

 

I'm about 80% with Sphingta.

 

Copper coil in the fridge yes bowl of water no.

 

I'd lay a piece of ridged foam insulation in the bottom with a

trough cut into the foam for the copper coming from the center.

Run the in and out piping through the side of the fridge.

You can lay a sheet of metal on top of the coil then you can set your

drinks right on that.

 

I suggest the bottom so as to stay away from the freezer which is almost always

in the top, to prevent the water from possibly freezing when the pump is not running.

 

The smallest submersible fountain pump ( $12 - $16 Harbor freight ) pumps 60 gallons

an hour.

 

Here is the thing to watch out for....

Make sure the pump offers enough resistance to flow when it is NOT running.

The water in the tubing may tend to automatically flow with a temperature differential.

Without getting into a big thermodynamic discussion, just believe me that it can happen.

This would tend to cause your set-up to cool below the set point of your thermostat.

 

Craig

[cold shot]

hey tinkerfive, i like your idea. i might even give it a go if i have that cooling problem. our t/stat is set at 72 degs year round. in the summer i just turn the tank lites down so they dont heat up the water. just my .034cnts worth. later ,gotta go to work now. Dave

[roscoedoh]

Ok Fellas:

 

I give up. Where I can find someone with a length of (preferably coiled) 1/2" stainless steel or aluminum tubing for sale? I've looked locally at Lowe's and all I can find is the stainless clad PVC stuff. What I need is a 3'-5' piece of non-copper tubing 3/8"-1/2" OD with a threaded fitting at each end and that I can coil into something like a 10" diameter coil. Any of you guys have a line on something like this? I've Googled "stainless steel tubing" and "aluminum tubing" until I'm about cross-eyed. Help please.

 

Thanks,

 

Jason

[donmarkey]

Check for any local food service equipment companys or pop or beer distributers. Most installers throw pieces that small away.

-Don

[donmarkey]

Check these guys, I seen kits but maybe they have replacement coils.

-Don

http://www.beveragefactory.com/draftbeer/k...cnic-kits.shtml

[swamprat]

Try your local refrigeration supply store. What you are more likely to find is aluminum tubing and compression type fittings. Or try the junk yard/recycling center.

Won't pumping cold water into your tank shock your fish or give them eck or ick or however it's spelled?

 

Swamprat

[roscoedoh]

Won't pumping cold water into your tank shock your fish or give them eck or ick or however it's spelled?

 

It shouldn't. Ick is caused by the shock of a sudden decrease in temperature or a contant low temperature. Since I would be pumping a relatively low volume of cool water in a larger body of warm water, I do not forsee the change in temperature to be problem.

 

With tropical fish you need the aquarium to be somewhere between 72* and 82*. The lower range is not a problem for me for most parts of the year because a regular aquarium heater will keep the temp above that 72* thresh hold. However, during June, July, August, and most of September, it usually stays above 85*+ inside the house during the day while I'm gone and not running the A/C. My plan is to lower the aquarium's temp by maybe seven degrees tops and keep it somewhere between 73* and 80*. If I can pull this project off as I envision it, I will have an electronic thermostat that would turn the pump on to push water through the refrigerated coils when the temperature rises above 80* F. And, should something go wrong and the temperature fall below 72*, the thermostat in the heater should cycle it on to warm the water up. I figured that by setting the heater for 73* and the chiller for 80*, I should be able to keep the aquarium somewhere in that range which is perfectly acceptable. (Hopefully)

 

Next question:

 

As an off the cuff guess, if I can find a refrigeration or brake shop locally that stocks 1/2" stainless steel or aluminum tubing, should they be able to bend it into a spiral for me? I'm going to call around this week and see what I can turn up.

 

Thanks for the help and all the feedback guys!

 

Jason

[tinkerfive]

Jason said

 

"What I need is a 3'-5' piece of non-copper tubing "

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

 

So what is the problem with copper?

 

Are the 'tropical' fish salt water as well?

If fresh water tropical, I don't see the problem.

 

Another solution is just to use plastic.

If you were to triple the length in plastic ( IE: 9'-15' )

I think that you'd get at least equal heat transfer.

The plastic tubing for uses like an ice maker is available

in any home center and it comes in lengths like 10' - 20'

 

Craig

[roscoedoh]

I have been cautioned away from copper tubing because small amounts of copper can be highly toxic to aquatic life.

 

Vinyl tubing may just be the best thing to use if I can get the heat transfer. Plus, I can get a 10% discount if I buy it at Lowe's.