[underseaworld]

The basic layout was just that. I used a siphon method. The water would go from the top of the tank and down into the fridge. The water line was coiled inside the fridge and then I placed it on the coldest settings. Slow dripped it from the fridge to the sump using the plastic shut off vaulve. You can get that at the same place you get the water line. The pumps in the sumps would return the water back to the tank. I would play with the shut off to allow the water to drip into the sump at a cool temp to bring the temp down a few degrees. It took some time to get it to where I needed it but it was a lot cheeper. I got my small fridge at best buys. I had the space to place so that it was off to the side of the tank and out of site. It also kept my sodas and beer cold. I found out if I kept the fridge full of sodas and beer that the fridge ran more effieciant. And by the way todays temp is 108. I hope I cleared it up better for ya. If I would do it again I would add an inline shut off on the top of the fridge also. Make it easy to disconnect the line incase I need to replace the fridge for anything.

[trigger happy]

what did you use to seal the holes you drilled?

[underseaworld]

I just some silicone

[trigger happy]

you said you are dripping it into the sump. I am thinking of just plumbing it into closed loop pump I have which is a mag 12. do you think this would make it to cold?

[underseaworld]

Well The dripping would work because I could controll the flow of the cooler water. You do not want the water to flow to fast through the lines because the water will not cool down enough to make a change in temp. in your tank. The drip method worked for me. I started out with a slow drip and then went with a faster flow after the water got cool. Then I had to adjust it from there to get it to provide a good temp. It took a while to get it to the point where it worked but it did work. Buy working from a fast flow to a slower flow the water would never get to cold. Not sure if that makes since to you. If you use a pump to flow the water I would think it would flow the water too fast so that it would not cool water down.

[trigger happy]

I could still use the pump but put two valves, inlet and outlet this will control the flow.

[underseaworld]

As long as you can control the flow you should be fine. The one thing you may also have to do is add more length to the water line in the fridge. To make the water colder.

[MarkS]

Neither the refrigerator nor the freezer idea will work or work for long. The compressors in them are designed to remove ambient temps, and then once there, shut off until the temp rises again. The insulation in the panels ensures that the temps remain stable inside, for the most part. They are not designed to run for extended periods of time, which would be required to remove a constant level of heat as you see in an aquarium. All you'll end up doing is burning out the compressor.

[underseaworld]

I can say for sure it worked for me. I had it for three years plus. That is why you need to have a slow water flow wrapped in the coiled lines.

[MarkS]

You were either:

1.) Lucky
2.) Your refrigerator has a compressor rated for continous running.
3.) Your refrigerator uses a pelt and your electric bills are sky-high.

All residential refrigerators and freezers that use a compressor, use a compressor that is NOT rated for continous operation (A/C compressors ARE rated for continous operation). Running a constant heat load through the refrigerator, no matter how slow, is no different than leaving the door open. The compressor will continue to run until it burns itself out. If it does shut off during this time, its a thermal-overload tripping and has nothing to do with the thermostat.

I went to school for refrigeration. You cannot do this guys. Sorry.

[SKRIZ]

Mark-

Once the freezer has reached a certain temp, let's say 37 deg, the compressor shuts off and it maintains that temp, right?

If you pass tank water through coils very slowly through this, would this raise the ambeint temp enough to trigger the compressor back on and keep it on continuously?

If the coil is at the bottom of the freezer, and you have ice packs stacked on top, would that help? The icecaps would help cool the heat of the coil?

[MarkS]

Originally Posted by SKRIZ

Mark-

Once the freezer has reached a certain temp, let's say 37 deg, the compressor shuts off and it maintains that temp, right?

Yes. Since the panel insulation is not 100% effecient, the outside ambient temp will slowly raise the temps inside, at which point the compressor comes back on. This is assuming that we're talking about a freezer that has not been modified to run as a chiller.

Originally Posted by SKRIZ

Mark-
If you pass tank water through coils very slowly through this, would this raise the ambeint temp enough to trigger the compressor back on and keep it on continuously?

Yes. It depends on how the thremostat is set up. Lets say that the thermostat is set up with a 1° temperature differential. When the tank water raises the temp in the freezer one degree above the set point, the compressor will kick on, bring down the temp and then shut off. This is what its supposed to do. However, there is no end to the amount of heat being added. This will result in the compressor constantly cycling. Compressors are not rated for that. That's the best case scenerio.

The worst case scenerio is if the manufacturer sized the cooling system too close or you're dumping too much heat inside, then the compressor never shuts off and over heats. This will trip the thermal overload, shutting off the compressor until it cools down, so the unit seems to be acting normally. Eventually, the compressor will become overloaded and burn out.

I do not remember the math, but it is better to run the water faster through any chiller, rather than slower.

Originally Posted by SKRIZ

Mark-
If the coil is at the bottom of the freezer, and you have ice packs stacked on top, would that help? The icecaps would help cool the heat of the coil?

No, the heat would still be present. At most, you'd just melt the ice packs closest to the tubing.

[trigger happy]

best buy has them for 50 bucks, I think for 50 bucks to last 2 to 3 years is worth the try over 400 to 600 bucks, would you not agree. You seem like negative in your post about wasting time. It works for one guy so it could work for all.

[MarkS]

Originally Posted by trigger happy

best buy has them for 50 bucks, I think for 50 bucks to last 2 to 3 years is worth the try over 400 to 600 bucks, would you not agree. You seem like negative in your post about wasting time. It works for one guy so it could work for all.

Um, no. I'm not being negative, just stating the facts. "It works for one guy so it could work for all." is one of the most assinine comments I've heard in a long time, not to be rude or anything. The truth is that neither I nor you know why it worked for him and neither I nor you can verify that it actually worked for him. To make that kind of statement without any facts just doesn't make sense. I'm a hardcore DIY'er and if this was possible I'd not only promote it, but I'd do it. I'd assist anyone trying it.

The fact is that it will not work, has been tried MANY times (do a Google search) without success and would not last for more than a month or two. Not to mention the fact that the cheap refrigerators are now using Peltier junctions, which cannot remove indirect heat very effeciently and use absolutely MASSIVE amounts of current. Your electric bill would jump through the roof, assuming that the pelt doesn't overheat and burn down your house first.

I'm not saying all of this to make myself look smart or to spoil everyone's fun. I actually know what I'm talking about, have designed compressor-based cooling systems for computers and will probably be making one for an aquarium. This is something that I have spent the past two years researching and even went to school for, although I decided not to make a career out of it. If anyone wants to build a compressor-based system, I will be happy to assist in the design.

[DonW]

It take one BTU to to drop water temp of one pound of water by one degree. This is with absolutly no heat sources such as pumps and lights. A typical dorm frig pulls out 100 btu. The btu input of lighting and pumps out weights the out by many times.

Don

[Ratpack]

I hate to bring up an old thread, but I had a thought on something similar to this and wanted to run it by everyone. I had thought about buying the mini fridge and placing an acrylic chmber inside of it. Then water would be pumped from the sump into the chamber and then have a return line back to the sump. Since it is in a fridge and not a freezer, the worry of freezing up isn't there. Then I can regulate the flow so that it is slow enough to allow the chamber to cool down and just slowly add cooled water to the sump. If I can't come up with a "cheap" solution to heat, I may have to scrap any MH lighting and go T5. The wife would flip if I asked to spend $400-$600 on one thing and all it did was cool water.

Oh and a bonus would be, depending on the size of the chamber, I could keep cold drinks in it for reef viewing periods!!

[Reefland]

I really doubt that it would work. Besides, are you sure you will need to cool the water down outside of using fans?

[Ratpack]

Originally Posted by Reefland

Besides, are you sure you will need to cool the water down outside of using fans?

Actually I don't and won't until after the tank is build. This is just a thought as I think towards the future and make my decisions.

[SKRIZ]

That's no different that running a hose in the freezer.

The only way this would work is to dismantle an in-window a/c unit and modify it with a titanium tube. Insert this tube into a chamber where tank water will pass through. the water continuously pass through this chamber. Only that a/c unit is regulated on/off. When the unit turns on, the freon passes through the titanium tube, cooling the water.