DIY Chiller or am I crazy?

BCWolfen · #1 03-22-2005, 03:52 AM

Ok this may just a completely crazy idea that would never work but I wanted to run it past the pros and see what everyone thinks.

Would it be possible to build a DIY chiller out of a bar fridge?!?!?
They are cheaper than a chiller especially if you get one used in teh buy and sell.

My thought is.
Drill 2 1" (well slightly larger) holes into the side near the bottom. Feed some 1" flex tubing through it so you have a stack of say 3-4 coils lying in the bottom. Connect this to 2 valves (so you can completely exclude it form the system) and 2 couplings. Then run a smaller pump or Aqua Clear 5000 powerhead or even branch it off the skimmer.

The fridge can also be used to keep your Phyto and the freezer portion for all the frozen foods. The top makes a great stand for flake foods, equpiment etc etc.

Would it cool the water enough?? Or am I sniffing too much glue tonight??

LMK

Stasher · #2 03-22-2005, 03:57 AM

I have read this done elsewhere but the only worry is the automation of something like this. You are always cooling the water, what if your heater were to quit?

Tarolisol · #3 03-22-2005, 04:20 AM

You could always connect it to one of those neptune systems, just plug it into the chiller part and it will only turn on when needed, might not be good for keeping frozen food in thought after. Also i would be carful about where you drill into.

Jaws · #4 03-22-2005, 04:20 AM

Do a search on Reef Central regarding this. There has been many discussions about this on there. I think overall, they decided it was a bad idea but I haven't looked into it myself, just heard. Hope you find something.

Delphinus · #5 03-22-2005, 04:21 AM

I think the basic problem is that the duty cycle of the compressor is nowhere near what it needs to be, for a tank chiller. Typically your fridge compressor runs for a little while, then the inside is cool, and the motor "rests" while the fridge stays cool until the temperature rises just a wee little bit, and the cycle begins again.

In the case of the tank, the temperature is always warmer than the temperature setpoint of the fridge. So the motor is always running, it never gets that "off" part of that cycle.

So in the end, it works, but only until the motor burns out.

golden69_ca · #6 03-22-2005, 04:33 AM

if u were going to use a frigde u would have to run it full time never turning it off and puting the pump on a temp control that would put less stress on the fridge .as for the compressor i have seen some of the maufactured chiller units by companies and they use the same ones , the heavy industrial units is when they get into diferent syles of compressors .

Delphinus · #7 03-22-2005, 04:56 AM

Is it more of a myth then, that they tend to burn out (if it's the same compressor model)? Or do I just have the basic concept wrong?

Nemo · #8 03-22-2005, 05:56 AM

First you would need to run a large section of coils probable more like 40-50 feet of 1/2" tube. This would alow you to have a fair amount of water in the fridge being cooled.
Second I would run a dual solinoid valve one on the outlet from the fridge and the other from your return line (this would elliminate the need of a pump and maintain no pruser in the line so no risk of blowing a line) off of a temp controler to turn on when cooling is needed.
Third I would probable run a timer on the solinoid so that you would only have it open for about 1-2 minutes, any more time than that and the fridge would not be able to keep up. If you run a large coil in the fridge there should be plenty of cooling water in the coils to do the job.

This should solve the problem of having the fridge cycling all the time and give you a cheap chiller.

JMO

Robert

BCWolfen · #9 03-22-2005, 07:11 AM

Hmmm all good ideas. Aside from being an interesting topic its great fun to see all the gears turning in everyones heads. We all turn into Tim the Toolman and want to run to Home Depot with a no limit credit card, buy 20 fridges and try different variations.

Rikko · #10 03-22-2005, 07:12 AM

I think the main problem with cooling our tanks is just that chilling technology isn't very good. Even a full size kitchen fridge can't do as much as you'd think. It kicks into the duty cycle by cooling the air inside the fridge, but before long everything in there is cold. No cold air is really being lost because it's so heavily insulated. Like has been said before: temp drops a bit, compressor goes back into action, then off again.

But now run some warm aquarium water through it and ask it to constantly be cooling that water down.. How much, really, can a fridge be expected to cool when there's a neverending supply of water heated by the pumps, lights, even the surrounding room?

Lots of guys have good luck using bar fridges to keep their tanks cooler during the hot summer months, but I think for any serious temperature control (ie. try running a 90 gallon Pacific Northwest biotope system), we just can't do it.

I remember one guy in Cali dug a huge hole in his back yard and ran several dozen feet of tubing underground to the water table and then back up.. It was sufficiently cool down there to keep his tank well under control,