Chiller

[Noobalicious]

Was wondering if this idea might work for a DIY chiller.

 

Any input would be appreciated.

 

I was thinking of taking one of those smill refrigerators, the size advertized for dorm rooms, and modifying it. The idea is to cut 2 holes in the side and then run 3/4 or 1 inch aquarium tubing through it.

 

There would be a loop of about 15-20 feet of tube inside the fridge. The pump moving the water would be very low flow, to make sure the water had a decent amount of time to cool.

 

Does this sound like something that would work?

[Coral Hind]

I tried this about ten years ago and it didn't work well at all. The vinyl tubing does not transfer the heat well enough so there was basically very little cooling transfered.

 

What I did end up doing was taking a sawsall and cutting the fridge open to remove the compressor and the two coils out in one unit. I then mounted the compressor and condensing coil under my stand. I took the evaporator coil and carefully bent the lines so it went into my sump. The evap coil was enamel coated so there was no fear of rusting. I used that for several years on my 125g until I sold the setup before I deployed to Iraq.

[Matt LeBaron]

Interesting thought, you I would think that you would need to have some type of metal tube for inside of the fridge because I don't think plastic tubing would transfer enough cold to the water running through it. Unfortunately I don't know what if any type of metal tubing would be saltwater safe, lacking that the thinnest plastic tubing you could find would be best.

 

Got me thinking though, wonder if I can find a cheap mini fridge somewhere...

[Noobalicious]

Interesting thought, you I would think that you would need to have some type of metal tube for inside of the fridge because I don't think plastic tubing would transfer enough cold to the water running through it. Unfortunately I don't know what if any type of metal tubing would be saltwater safe, lacking that the thinnest plastic tubing you could find would be best.

 

Got me thinking though, wonder if I can find a cheap mini fridge somewhere...

 

 

I think the only metal that is really "reef safe" is titanium. They sell titanium tubing, but it isn't cheep.

 

Instead of a dorm fridge, maybe a used mini freezer might be cold enought to be usable with plastic tubing.

[Chad]

Heat transfer is not very good through vinyl into air...

What you could do to imrpove it though, would be to imerse the coils of tubing into water would help this (big bucket of water in the fridge with a small pump to keep the water circulating around the coils).

You could also buy a titanium heat exchanger like those that most chillers have and solve the problem altogether (not cheap though).

[Kevin Garrison]

http://saltaquarium.about.com/od/diychillerplans/ss/sbsdiychiller.htm

 

This link and several others I looked at suggested 3/8 hard plastic tubing as vinyl tubing is not a good choice for this application as Dave stated in his post.

[Chad]

Going more on your freezer idea, you could immerse the tubing in a fluid with a lower freezing temp (alcohol perhaps?)

[bbyatv]

Google this idea. This and many other variations have been tried with some success. From my reading, the best DIY chillers are made from Room Air Conditioning units. You have this issue called duty cycle that plays in to this equation and the dorm fridge will not last long or do a good job in this type of application.

 

I DIY nearly all of my stuff and I ended up buying a chiller for like $250. I am sure you could find one cheaper used.

 

Good Luck.

 

Bruce

[DaveS]

If anyone is interested, I have a 1/2 HP Aquamedic chiller. The chilling components work fine. However the pan (which is the space that the coils is stored and the tank water is circulated through) leaks. I never got around to messing with it as I got a good deal on a replacement chiller. Anyways, if anyone is interested in a pretty easy DIY project, I'm open to offers!

 

My guess is that you could probably convert it into some type of drop in unit very easily.

[zygote2k]

The other option is to use lights that don't emit heat, get rid of excess powerheads that generate heat, and use eductors to generate more flow with the same amount of electricity. A fan blowing across the water will add to the cooling effect and so will keeping the A/C in the house lower than the maximum high temp of the aquarium.

the other thing about a chiller is that they make noise and generate a fair amount of heat that needs to be ducted to another area.

[gmubeach]

Dorm room refigrator won't work I tried it... the cooling feature is meant to get cold and stay insulated the holes to get the water in ruin the fridge. Its much cheaper to just buy a chiller in my opinion... Or go leds that works too...either way its an expensive hobby.

[treesprite]

If you go to the Goodwill thrift store, you will often find mini fridges for like $15 bucks - that's how I got mine. I ended up not using mine, so maybe I'll entertain the thought of trying to make a chiller out of it.

[Charlie]

Coral Hind is right that plastic, vinyl or pvc won't work because, one of their features is insulation against freezing. I know that soft copper pipe won't work (at a place I worked several years ago, we had 50' of 3/8" copper tubing in a fridge for cold water), but you could consider aluminum (I don't know if aluminum is reef safe) or soft steel tubing. the thermal transfer properties of metal is exactly what you're after. As a side benefit, you have a second refridgerator for beer. You could even keep a keg in it, put a tap on the side and host the next tank tour.

[paul b]

I used to have an urchin collection business and I had to keep the urchins cold so I could put hundreds of them in a tank. I built a chiller that was able to keep the water at 45 degrees.

It was just an office water cooler, the type that you put a five gallon plastic bottle on top of. There is a sump in the top that you can fit about a half a quart of water. In there I put a powerhead that was connected to a coil of steel tubing. Steel tubing is very cheap and is used for brake lines in cars and trucks. I coated it with fiberglass resin and put it in the bottom of the urchin tank. On top of the small resivour where the pump was, I put a styrofoam cover. The resavour was filled with water.

I had it running for about two years and did not have any problems. Urchins are much more sensitive to metal poisioning that fish and I never lost an urchin.

[Origami]

I'm surprised that nobody's linked this article:

http://www.beananimal.com/articles/dorm-fridge-aquarium-chiller.aspx

 

Ultimately, it comes down to heat loading in the tank and the capacity of the refrigerator to remove that heat. Small tanks (under 20-30 gallons) would fare better than large ones. Unlit tanks would fare better than one's with bright lights, too. Please note, the reliability of the compressor might also be an issue to consider.

[treesprite]

Doesn't contact time with the cold air make a difference, regardless of material? What about using a bunch of long coils of 1/4" airline tubing (like at least 10 of 50 feet, but the more the better)? Drill a bunch of holes in each of two pieces of PVC, attach one of each end of the coils to those holes, then the other ends to the holes in the second piece of PVC. All of that would be on the inside of the fridge, so no need to worry about the airline coils getting caught on anything or looking ugly or whatever.

Edited April 10, 2010 by treesprite

[Charlie]

Forrest, unfortunately, not so much. The vinyl that airline tubing is made out of doesn't transfer heat very well (remember that cooling is transfer of heat away from what you want cooled). Not to mention, you really don't want to open the coils, they are filled with refrigerant (usually R-22, like your house's AC). If airline conducted heat then I think that there would be millions of cooked guppies rather than guppies that die from lack of water changes and being in tanks that are way too small. In order for vinyl to work, you'd need a temperature close to freezing and about 2 miles of tubing. Paul has a point that break line (unused) is pretty cheap and the steel conducts heat like a charm. You really wouldn't need more than 15 feet, coiled in the bottom of of the fridge. They also make fittings for the break line that make the plumbing pretty straight forward.

[treesprite]

Well, my mini fridge sits in the corner unplugged doing nothing....

[Charlie]

Forrest, you could run a few lengths to brake line, coiled up in the bottom, through it. CAREFULLY drill a couple of hole in the side, as low as you can (about even with the floor of the fridge). You can put bulkheads in the holes, by fill up the remaining space with caulking. Then you have a DIY chiller and a beer fridge.

[Chris-]

Yea, for the work one has to do given the output results, buying a chiller is the only way out on this one. I HAVE to do everything myself, and, this is one I give up on. Now, if you can find a cheap broken chiller on ebay and use your mini fridge with the chillers cooler coil, that may be an option.

Edited April 14, 2010 by Chris-