Chiller Idea

[speedingredline]

I have been thinking about a homemade chiller for my 240 gallon reef project. I thought of buying a chiller, but since my tank is on a support wall that backs the garage, I'm kinda stuck for a location for a chilling unit. So I started thinking, not a good thing either. Why not drill 2 holes into the floor, the tank is on the ground floor, and bury a 55 gallon drum or someother plastic container in the ground under the house. I would allow it to gravity feed from the sump, or fuge maybe down into the drum, then use a pump to bring the water back into the fuge or sump. I figure in the summer time the ground in the crawl space would stay fairly cool, then in the winter I could bypass the in ground tank, and redirect the water. Any thoughts.

 

[Charles99]

i've heard of this before. actually the person I've heard it from had a 100g. in-ground container. excellent way to increase your water volume.

 

[speedingredline]

good for the summer time, but would lose the volume in the winter. I actually heard about while water cooling my computer. I guess in Europe its a popular way to cool your pc. I may have to give it a go.

 

[KEITHMC]

why not keep the water in the well fresh in a closed loop and run it through a coil in your main sump to minimize possible containmation from a leaky drum and keep your water volume the the same summer or winter

 

[spitefull]

ok cool idea and got to be cheaper than a chiller,keithmc any ideas on material for radiating fins for the sump?? im wondering about the plastic cores on some new cars somehow coiling a mile of tubing in the sump seems tricky thanks spite.

 

[speedingredline]

I could take that route as well, but that would require drilling the sump, and I don't want to do that.

 

[BeanAnimal]

There are several issues you need to think about.

Firstly, the water must always be moving. Otherwise it will get stagnant and the nasties will start to grow.

Secondly, you need to move the water through a coil. You can not simply pump it through a drum. The drum will not have enough velocity to keep any particulates in suspension. It will become a detritus trap and a HUGE source of problems.

The easiest to do all of this is to circulate water or other coolant through your geo chiller loop, in a closed system with a heat exchanger in or near your sump. In this way you can simply turn the cooling coil circulation off and have no worries of stagnant tank water. In other words, the same as a chiller, but with a geothermal loop instead of freon.

Hope this helps.

 

[KEITHMC]

Ok forgive my artistic skills but here is what I was talking about.

This is a simple version of a ground source heat pump the longer and deeper the ground loop is buried in the ground the more stable and the higher capacity it would be the only problem would be depending on where you live your ground temp may not be low enough to give you a sufficient pull down capacity if your ground temp is 60-65 and you want your tank at 77-80 that is a max of a 10-20f temp difference without employing a refrigeration system so you would have to have a very efficient coil in the sump ie some sort of coiled titanium for the best heat transfer to be able to see any tangible results. And yes I have thought about this at length because I just happen to have a self-contained soda machine sitting in my house(which has its own refrigeration unit and maintains a 15lb ice bath) all I need for that is a pump and a good titanium coil which will give me a 42f drop across the coil!

 

[robwsup]

It looks like a pretty sound plan. Geothermal cooling is getting fairly popular.

I thought this was going to be another dorm fridge chiller DIY thread!

 

[douggiestyle]

nutrient sink could be eliviated by draw and discharge on the bottom. the problem with a heat exchager would be the cost of the exchanger if using an efficient exchanger ie ti. or the efficiency vs energy used if not using ti and using poly.

 

[scrager]

nutrient sink/stagnate water will become a problem if you ever turn the flow off. you'd either need to run it all the time or have a way to drain it when you aren't using it.

also, a drum or large holding tank is not the answer. you want a coil in the ground to maximize surface are contact between pipe and ground. a drum would be just like a lake. you know how a lake can still be liquid even though there's snow all around it? large bodies of water take longer to cool down. that's also why a radiator is basically a long winding tube.

 

[douggiestyle]

cant become a sink if you stop flow to it. stagnate yes. could end with low redox if left to sit to long.

you are right about the large water body thing but mostly its due to the frost line. the water is geothermaly heated in the winter.

i know that a few people have had a heating issue when dealing with a basement sump.

 

[BeanAnimal]

Yes,

You will get much better rusults with 100 feet of tubing burried in a 100 foot trench, then you will with a few hundred feet of tubing burried in a 55 gallon drum.

When I put the deck on the side of hte house, I plan on putting a geo chiller tube in the french drain ditch. The length will be close to 80', and I plan on using about 350' of tubing (up and back on each side of hte 4" pipe). The tubing will only cost a few bucks. If it works.. great.

Bean

 

[skeeter_ca]

I used a geothermal loop for my 75 gal in my previous house worked great. Went under the house to the backyard and buried 300 ft of 1" pvc pipe 5' deep. Had a very small PH to always cuirculate water but when needed cooling, a temp contoller would start up a large PH and keep temp to 78. testing showed my tank would exceed 94 on hot days with everything running without the geo-loop. Would use it in my new house except tank is not any where near a outside wall i could use. Had to buy a 1/4 chiller.

 

[BeanAnimal]

You circulated tank water through the loop? That a long way to push water with a little PH.... Though 300' of 1" pipe did add some volume to your total system

 

[douggiestyle]

kieths got the right idea. the extra water in the tank acts as a storage system for cold water. would need one extra pump to work in the most efficient way.

the storage would make up for the low conductivity of the poly in the ground. cool the storage tank slowly. cool the fish tank quickley. the efficiency couldnt be compromised too much. similar devises are used in solar heated houses. this is the same but in reverse.

 

[douggiestyle]

<a href=showthread.php?s=&postid=7051871#post7051871 target=_blank>Originally posted</a> by scrager
a drum would be just like a lake. you know how a lake can still be liquid even though there's snow all around it? large bodies of water take longer to cool down.

oh and also just as a large body is to cool it is also to warm. it goes both ways.

a most efficient means would be to have a much larger sump in a cool place connected to your tank. it would be similar to trying to heat a swimming pool with sunlight shining on it. ever notice ( at least in the north) that an in ground pool never gets warm enough in the summer? got to run a heater? geothermal cooling. the suns alot stronger than a mh. also evaporative cooling involved.

 

[skeeter_ca]

Yes beanAnimal.

I had tank water circulating through the loop. It added some extra volume which was a benefit. I think it was about 150gph PH for constant flow. It would just trickle through. Then when needed the larger, about 500gph would turn on. Worked like a charm.