Homemade Chiller

[vayapues]

I have an idea for a homemade chiller and want to get some feedback from others. In particular from anyone who might have the slightest clue (I don't) about how to do the math required for such a project.
The Idea:
While cleaning a large animal drinking container today I noticed that the water in the container was very cold, despite the fact that the ambient air temp is 100 degrees today. I didn't test, but I would bet the water temp was 65 degrees if not colder.
Of course, the reason for this is because the ground is keeping the water cool inside of the pipes. I recall from a recent trip to a local cave that the temp in the cave is 50 degrees year round.
So.... how deep would I have to dig?
How much pipe would I have to run?
How strong of a pump would I need to circulate the water through the system?
I know there are lots of variables, like what pipe size, whether it is pvc or metal, what temp we are trying to achieve, what temp the soil actually is, etc. For the sake of argument lets say the variables are as follows:
1" pvc
Ground temp at 3' is 55 degrees
My goal is to cool water to 65 degrees
design thoughts:
I will dig a large deep hole in the yard. Say ten feet deep x 3' x 3'
then I will coil the pvc pipe as follows.
Side view:
_____________
|_____________
_____________|
|_____________
Top View:
______________
| ____________
| | ________ |
| | |______ | |
| |_________| |
|_____________|
I would then pump the water by taking it from one side of the tank, circulating it through my pipe, and then dumping it back into the other side of the tank.
Thoughts are greatly appreciated!
This may end up being a trial and error effort, but while not very expensive, it is labor intensive, and I would prefer to not have to dig a very large hole more than once!

 

[sweatervest13]

Geothermal Heating and cooling....
http://www.google.com/#hl=en&sugexp=les%3B&gs_nf=1&cp=7&gs_id=d&xhr=t&q=geothermal+heating&pf=p&output=search&sclient=psy-ab&oq=geother&gs_l=&pbx=1&bav=on.2,or.r_gc.r_pw.r_qf.&fp=69e57d2f89da56b8&biw=1024&bih=629
Click on the third link to wikipedia.. Also check out the sponsored link for home do it your self kits.
It seems to me that purchasing a chiller for a few hundred bucks is a way better value. Unless you are converting you entire home to Geothermal heating.
My 2 cents..

 

[snakeblitz33]

Use pex tubing with nylon fittings. You dont have to screw with making every single 90 d elbow a tight fit. They sell pex tubing in coiled 100ft lengths. You could make four or five coiled stacks in the ground and then back to the tank. You do not use tank water at all. You use (preferably ro/di water and a lift pump on a seperate system. Then, use a small coil of pex tubing to sit in your sump. Never have any of the pex fittings sit inside or over tank water.
Some people have big koi ponds in their back yards, and they run their cool pond water through the pond in tubes and run it into the house in a coil like what was discussed. The koi pond has an extra benefit of having a large pump running not only it, but chilling the reef tank water. Small 1/4 horse pool pumps would probably do it for you.
I dont know about you, but id rather dig a pond than a hole in the ground and fill it. Lol

 

[vayapues]

@sweateverest Thanks for the link. I have been reading on Google searches, and will check out the term you posted. Lots more research to do, but so far, the geo thermal option looks to be not only far cheaper to install, but also significantly cheaper to run. A pump uses a lot less power than a chiller.
But like I say, lots more research to do.
I like the idea of using pex. I hadn't thought of that, but you are right, that would be much easier.

 

[acrylic51]

Homemade chillers have been tried and attempted in the past with very little success.....Plastic, PVC offers very little cooling affect, so it would have to be miles and miles of coils to see any real draw down.....

 

[snakeblitz33]

To be honest, I'm with Acrylic. You're much better off in the long run if you go ahead and get a chiller.
Digging up your backyard might have some consequences. Make sure you "call before you dig"
I don't think that a high pressure pump will honestly be anymore efficient than running an efficient chiller.

 

[acrylic51]

Not saying it can't work....Just saying PVC/Plastic isn't the best to dissipate of heat.....And even underground IMO would need to be a good bit of piping.

 

[snakeblitz33]

Plastic is definitely not the best medium for endothermic reactions - it basically acts as an insulator. PVC may be a better insulator than PEX, however. PEX lines do tend to freeze in cooler weather a little easier - but they expand a lot better and aren't as brittle as PVC is. What medium would be ideal for geothermal cooling pipes?... copper perhaps... but you would have to do a lot of DIY to get it done just right.

 

[travelerjp98]

For sure though it was a different way of thinking.

 

[acrylic51]

Quote:
Originally Posted by travelerjp98 http:///t/392603/homemade-chiller#post_3490171
For sure though it was a different way of thinking.
Absolutely "love" the thinking just think a better material choice would work much better.....If you guys check out the other forum there has been a few that have done something similar to using GeoThermal to cool the tank. Might give better insight on material choices and other design ideas and concerns.

 

[snakeblitz33]

Geothermal cooling is just... not for me. I'd rather pay for and use a chiller rated for my tank. I don't think my wife would like me digging up the backyard just to cool my fish tank by 2F. . LOL

 

[lol]

I kind of agree with what Snake and Acrylic are saying here - you might be better off with just the right sized chiller and using equipment that is low wattage... and maybe even investing in some LED lights so that your tank doesn't have that much heat introduced into it in the first place.
Just my .02

 

[Viper1103]

Your only limit is your imagination and ingenuity u could use garden hose and a mini fridge/freezer but I do agree geothermal is an ineffective way to cool ur aquarium