DIY Chiller

[blk822822]

I have move to a home and have my tank set up in the garage and it gets hot in there. I thought about getting a $49 refrigerator from walmart and plumbing in a coiled hose and running it through a container of water inside the fridge to cool the tank water. Only problem is regulating the refridge so it dosn't get to cold. Anyone know how to make or get a temp controller to turn the fridge on and off? Or any better Ideas? I have an air conditioner I could run in the garadge but it's not insulated and would run non stop cooling the garadge. Any help would be great, I have never had a garadge tank befor, and am adding another as soon as I can get it picked up, a 180. My tank now is a 90gal reef.

 

[Ichthys]

dorm fridge chiller

I have move to a home and have my tank set up in the garage and it gets hot in there. I thought about getting a $49 refrigerator from walmart and plumbing in a coiled hose and running it through a container of water inside the fridge to cool the tank water. Only problem is regulating the refridge so it dosn't get to cold. Anyone know how to make or get a temp controller to turn the fridge on and off? Or any better Ideas? I have an air conditioner I could run in the garadge but it's not insulated and would run non stop cooling the garadge. Any help would be great, I have never had a garadge tank befor, and am adding another as soon as I can get it picked up, a 180. My tank now is a 90gal reef.

I was thinking about this as well, and have read posts of people who have done it, although with some problems.. rather than try to list them all, check out this post that details the issues with DIY chiller. http://www.cs.cmu.edu/~cap/raid/chillers/dormfridge/index.html
THAT BEING SAID, I am sure there are reefers who have done it succesfully, its just not a simple task...
Ichy

 

[Cwazy Clown]

you could probably build a peltier system for just as much but have it look alot nicer.

 

[blk822822]

I think the fridge could run on it's normal setting but have a temp controlled relay to turn on the pump to run the water through it. And plumb it into the tanks normal return line so it mixes the cold and tank water. JMO.

 

[DonW]

The old dorm frig thing doesnt work. I bucked the naysayers and tried many different configurations, some high tech and some low. None of them worked, the money spent could have easily purchased a couple used chillers.

Don

 

[thatguy559]

you can do a couple things.

1. run the pump throught the refridgerator continuosly and let your heater regulate the temp

2. take out the freezer seperator run a coil of water line connected to a pump and have the pump turn on with a in tank temp controller (aqua jr)

number 1 is how i did it when i lived in lemoore ca (110*) summer day/night

 

[DonW]

The only thing that works even remotely close to being acceptable is to run a huge coil through a bucket of nearly freezing water kept in the frig. If its hot out or the tank is running large pumps and halides then even that wont do much if anything. I wouldnt even try it on a tank over 20 gallons.
The article posted above is spot on and has been proven time and time again over the last couple decades.

Don

 

[thatguy559]

210g tank with a dorm fridge temp never over 80*

 

[DonW]

http://www.beananimal.com/articles/dorm-fridge-aquarium-chiller.aspx
http://www.thesea.org/diy-aquarium/controllers_chiller_ac.html

 

[thatguy559]

thats nice so an article is going to tell me that what i had set up didnt work.....ok mr know it all

 

[Ichthys]

hmmm

I don't believe Don was trying to be a Mr. Know it all, I think he was trying to give good information to the OP who was questioning whether to invest money in building a DIY chiller. For every person who says they have successfully set up a dorm fridge chiller I have read 10 accounts saying it simply doesn’t work long term. I am not telling you what did or didn’t work in your own system, that would be foolish as i wasn't there and therefore take your word for it. Nonetheless, for most people it doesn't seem effective. Also in one of those articles it mentions that while some people report adequate cooling with DIY chillers, it is more often that the lower temps are a result of some of other variable that is being overlooked. Correlation does not equal causality. A good example of this is when someone switches to a different brand of supplements and gets good coral growth and attributes it to the supplement, when in reality the growth was due to a flow change or lighting change.

Once again, I'm not saying that your DIY chiller didn’t chill your tank below 80, just that as the commercials always say, actual mileage may vary, and the OP might be best served in seeking alternative methods to temperature control.

With all due respect
Ichthys

 

[ac7av]

I’ve put a lot of thought into the same thing since I’m in the appliance repair business. You can come up with lots of ways to do it in a frig but the problem is most of the small dorm size frig are really only capable of cooling a small tank because of the size of the compressor. Along with the heat exchanger you would have to build or buy it doesn’t make any sense to do so. It would cost you just as much as just buying a chiller after all the materials and pumps to say nothing of the time in making it. About the only way I see a good chance of doing something like that is to use a small chest freezer with a plastic liner and a temp controller and use the chest freezer compartment as a fuge or sump. No special preparations would be necessary other then to seal off the drain that most of them have. This would give you a better chance and a lot less material to do a better job since most freezers will have a compressor with a higher btu rating then a similar size frig.

 

[ac7av]

On a large tank like a 125 gallon tank a dorm frig will do little to nothing for the temp. the dorm frig ability to cool just will not do it. For example if you compare it in watts of heat and lets call it watts of cool. A dorm frig could cool at best for a old one that is not efficient, maybe up to 50 watts of cooling ability. A new frig like from wally world would at best give you 25 watts of cooling power. It’s just not worth it. The average newer (less then 5 years old) frig of say 20 cubic feet capacity will still only give you maybe 100 watts of cooling capacity. Refrigerators are really pretty efficient at what they do, and that is not cooling a fish tanks.

 

[tat2z_21]

In theory though with an extensive coil and a slower run through, wouldn't the cooling be right where it needs to be. If you were to take a 1200 gallon pump through 5 feet of coil, then I can say that it would not work. However if you were to increase the length of the coil (efficiently coiled 50 foot), and decrease the pump capacity, (MJ400) the contact time with the aluminum coil would increase and temperature could be controlled by a controller. Just my thought. I am no expert and doing this strictly off of theory. But I believe that a small refigerator would be able to efficiently cool even a 125 gallon. With a constant running of the refer and pump able to cutoff at certain temperatures I do not see where the problem lies.

 

[Ichthys]

We should test this

As a group we should do a controlled experiment. Heat a control tank to 85 degrees, make some DIY chillers, and measure temp drops, power use, ratios of BTU's to efficiency, we could come up with parameters and effectively put this whole thread to bed. Hey we could even have a contest. Build a DIY chiller for under 200 bucks and see who can achieve greatest temp drop in a 100 gallon control tank heated to 85 degrees. THe winner might even be the next Herbie or Stockman or reef aquaria chillers. How many DIYers have parlayed a good home brewed idea into a tidy little side business.

 

[NWDiver]

While I can't say for sure on a reef tank, I wanted to cool a 55 gallon tank from about 65F to 55F. I used a new dorm fridge, and ran a line through the freezer and the fridge with various lengths and materials including 6' titanium. The best I could get was -5 deg F.
So I have to agree that it is not a very efficient method.
Eventually I filled a 25 gallon cooler with RV anti-freeze, used the 6' piece of Titanium as the aquarium heat-exchanger, carefully placed the heat exchanger from a dehumidifier into the cooler and used a temp controller to turn the dehumidifier on and off. A maxi jet to push water through and it worked like a champ.
So if you are into the pile of junk in the corner look, or really want to DIY, it can be done.
FWIW I have a real chiller now

 

[TotalVapor]

Back in the day we used a deep freezer as a sump. We picked it up at a garage sale for $100.00. It was almost always running and the cost to run that for the two months we tried it was crazy. It is more expensive up front but cheaper on the monthly bill if you did in fact just run a chiller rated for your system.

Drop ins are nice but have to be close to the sump / tank. I like the inline so I can feed it through my return pump or my overflow. Another idea is to get the $99.00 AC unit from home depot for the room your tank is in and use that. At least you feel some of the benefit from it too.

For now I have 3 fans on my tank / sump. I control it with my aqua controller based on the season table. Every time I tell someone this they asked me how I programmed based on season table so here it is:

If Temp  < RT+-0.4      Then HET ON 
If Temp  > RT+0.0      Then HET OFF
If Temp  > RT+0.5      Then FN1 ON 
If Temp  < RT+0.0      Then FN1 OFF
If Temp  > RT+0.3      Then FN2 ON 
If Temp  < RT+0.0      Then FN2 OFF
If Temp  > RT+0.5      Then FN3 ON 
If Temp  < RT+0.0      Then FN3 OFF
If Temp  > RT+1.0      Then CHL ON 
If Temp  < RT+0.0      Then CHL OFF

FN2 is sump fan if the temp gets to be .03 of a degree higher than season table it will turn on

FN1 & 3 are on the top of the tank and will kick on if the temp is a 1/2 of a degree higher than the season table.

HET is set to go on if the temp drops -0.04 of a degree and turn off right at the season table temp.

If the temp gets to be 1 degree over season table the chiller will turn on and of course turn off at season table temp.

HTH Someone

 

[ac7av]

As a group we should do a controlled experiment. Heat a control tank to 85 degrees, make some DIY chillers, and measure temp drops, power use, ratios of BTU's to efficiency, we could come up with parameters and effectively put this whole thread to bed. Hey we could even have a contest. Build a DIY chiller for under 200 bucks and see who can achieve greatest temp drop in a 100 gallon control tank heated to 85 degrees. THe winner might even be the next Herbie or Stockman or reef aquaria chillers. How many DIYers have parlayed a good home brewed idea into a tidy little side business.

That looks good on paper but will not be accurate. If you heat the tank, even the ambient air temp will cool it. Unless you do the test in exactly the same environment with each different project build you will not get any consistent results. The best thing is to just use the static temp of an un heated tank. Then the temp drop below that would give you a better idea of the units capabilities. It works just like a heaters ability to raise the temp above ambient temp.

 

[ac7av]

In theory though with an extensive coil and a slower run through, wouldn't the cooling be right where it needs to be. If you were to take a 1200 gallon pump through 5 feet of coil, then I can say that it would not work. However if you were to increase the length of the coil (efficiently coiled 50 foot), and decrease the pump capacity, (MJ400) the contact time with the aluminum coil would increase and temperature could be controlled by a controller. Just my thought. I am no expert and doing this strictly off of theory. But I believe that a small refigerator would be able to efficiently cool even a 125 gallon. With a constant running of the refer and pump able to cutoff at certain temperatures I do not see where the problem lies.

The problem is not the coiling. The compressor of a small unit only has a small ability to move heat. It has nothing to do with dwell time in the coil. If the compressor can only move X amount of heat then increasing the coil 2 times will still only move X amount of heat.

 

[ac7av]

Really if some one had the time to plum it in a clear ice, ice maker would have a better chance of doing the job but they are not cheep unless you find one on CR or eBay cheep. There compressor and system are designed to cool water, kind of like a chiller. Water pours over the evaporator plate and back into the small sump built into the unit. They can usually freeze a sheet of 12in by 12in by ¾ in thick ice in less then 10 minutes. Certainly this would have the capacity of cooling a larger tank over 50 gallons.