Chiller, Free cold! Geo-thermal loop

Aschnell911

New member
I drove a 3 inch PVC pipe 8 ft. into the ground. On the top is a reducer to 1/2 inch pipe, the 1/2" pipe goes down to the bottom of the 3 inch. Warmed water goes in at 81 and returns at 73.5. it runs on a tiny fountian type pumg for ajust a few watts, which turns on with the hallides. 100 gallon tank has a 4 degree drop with zero change during high light phase!

MY question, I hate to spend electricity for nothing,, my heater kicks in until the halides get hot,, is there a thermostat out there that can control the pump? That way my free chiller works only when needed.

John Jay
Jacksonville Fl
 

Pyrojon

New member
Ranco makes a decent controller like this one. http://www.reefcentral.com/diy/ranco_electronic_temperature_con.htm

Basicly you set a desired temp for your water to be and you plug in your pump on the cooling side and plug your heater into the heating side and the ranco does the rest. They have a single stage model that will control heat or cool, and they have a dual stage model that will control both.

That's just one suggestion, there are others I just can't think of them right now.
 

dogstar74

Premium Member
Problem that I see, is that what if your water lies dormant within the chiller for say.... 3 weeks. Then one day kicks on. All that nasty stagnant water full of decaying dead photosynthetic plankton, will come pouring into your system and poison it. Personally, I would worry. Just my .02.
 

RCragg

New member
Hey I have been reading alot of the geothermal posts on here as this seems like a great way to cool the tank! Can you tell us more about the system? ie closed loop, sump water in and out, etc. I lived in Kings Bay for a while and I know I hit water at about the 3 foot mark, is the 3 ft pipe mostly full of water? Thanks for the post, Rick
 

Scuba_Dave

EMERTXE YID
Premium Member
Maybe have a very small pump going all the time, and a larger pump when needed?

What kind of pump are you using now?
How long did you run it to test?
Once the ground becomes heat saturated you may have less of a drop. Just something to think about
 

Hobster

New member
I don't grasp the concept?? You pump water into the 3" pipe and it then returns back up though the 1/2" pipe and then back into the tank? How much presuure does that take? A 8ft section of pipe cools a 100gal tank 4 degrees?
 

scrager

New member
sounds like he has a 3" pipe with a cap on the end that is 8 feet deep. a 1/2" pipe runs through the center of this 3" pipe and is open on the end. Pump water into the 1/2", it goes down to the bottom and then rises up where he probably has a fitting on the side of the 3" pipe for water exit.

hard to tell without a better description, pictures, or a diagram.

sounds like a neat idea though and easier than barrying (sp?) 300 feet of pipe horizontally.

how did you get a 3" pipe 8 feet deep without it filling with dirt and still put a cap on the end of it?
 

rstark33

New member
Just run the chiller 24/7 and use your heater to keep the temp where you want it. It will shut off when it exceeds you desired temp(when halides are on) and the temp shouldn't raise anymore as your chiller is keeping it down.
At least try it out that way before spending a ton of money. Also it would solve the stagnant water issue.
Great idea by the way.
 

Aschnell911

New member
Geo loop answers

Geo loop answers

I am not sure how to add pics,, I have em. The get the pipe in the ground I simply hammered it in with no cap on the end yet. I used an air compresser and a water hose to clean out the sand/mud from the pipe. once I was down 8 ft I need a come-along to draw the pipe back out to cap it.

As far as stagnent water,, it only turns on each day with the halides,, the coolness of the pipe in ground may help 72F down there. No pressure involved my tiny fountain pump has about 2 ft lift max and very low flow.

Since I hit the water table at 3 or 4 ft, the gound never warms and the ground water cools perfectly and uses only a cpl watts of electricity. During hurricanes with no power I can still cool my system very efficiantly!
 

exoticaquatix

In Memoriam
as far as i can tell, most people, including my self, are still a little hazey as to how exactly you have this chiller plumbed. is this close?

---------------------------------------------------------------]
]
========================================= <-- in
]
----------------------------------------------------------[]---]
\\
\\
\\ <-- out


-nick
 

exoticaquatix

In Memoriam
crap, that got messed up. ok, so the out is shifted up twords the "cap/reducer". got me? 1/2'' in and down to the bottom? is the water being pumped from the top or bottom? it seems easy enough, effective by your experience and cheap. now all we need to know is how to make one. thanks.
-nick
 

scrager

New member
i'm assuming it is something like this:

855848ft_geo_loop.JPG
 

Hobster

New member
However it is plumbed, I still don't understand how there is enough heat exchange through a 8 ft piece of PVC pipe to actually lower the temp of a 100 gal tank by 4 degrees?
 

scrager

New member
small pump=low flow.
all the water that goes in comes out at ground temp which is substatially lower than tank temp.

i don't know for sure. maybe he doesn't have a huge heat problem like was said before.
 

Aquaduck

New member
This can work in theory if the ground is cold enough. Can you measure the water temperature at the bottom? Turn off the water pump and remove a hose and drop a temp probe to the bottom. Wait a few hours or until the reading stops changing. What does it say?
 

Pyrojon

New member
The temp under ground is known and the information is available. (Though I couldn't tell you exactly where). Once you drop below a specific depth, which is only about 4 feet as I remember, the temp is constant and that temp varies by region. For example, here it's about 54F, so I hear.
 
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