Earth Chiller (1 Viewer)

[dfimble]

I have been contemplating ways of reducing the time my chiller runs without having to add fans. (They are too noisy and error prone)

So I did a quick search and found that UH has already done a study on ground temperature and found that at 10 Feet down the earth stays a constant 72 degrees F.

So, I was thinking of sinking a 100 Gal container with a 1 inch line going in and a 1 inch line going out about 10 feet down. The pump that pushs the water through this will be in the sump and the return will be plumbed to go through the chiller and back into the sump (Not the tank due to head presure). Also, the chiller will be outside as I can't stand the noise or heat anymore.

Besides never being able to clean the container 10 feet down, can anything think of why this would be bad? My first thought is, what happens if the 10 ft down container is hotter than tank? Resolution will be to shut the valve and force the water only through the chiller and back to the sump.

Any comments would be greatly approciated as I really don't want to dig a hole that deep.

Thanks,
David

p.s. At 3 feet down, right now, a one gallon jug is staying a constant 64 degrees (for the last 2 weeks)... but it also isn't the middle of summer yet either.

 

[Ulric]

I think there are some...older scattered posts on it.

I kicked around the idea of trying to make a concrete outdoor tank, with a 'sump' that extended below surface ground level... too many things to get done before startnig that little project/experiment.

 

[Guest]

Interesting idea David.

How do you plan to clean the sump if something was to get stuck or just some type of maintenance? How would you pump the water up? I know they have submersible pumps.. but what if that ever died?

 

[Guest]

geothermal cooling is not as effecient as some folks believe. Also, finding a container that would hold against pressure and stay completed sanitary on the inside would be difficult.
Too many variables that are "buried"...IMO

 

[toan]

well have you taken the heaters off your tank and seeing what the temperature goes to?

and what degree are you setting your chiller to that makes it go on so much?

mine comes on for 30 seconds and shuts off every couple hours

 

[Niko5]

dig a hole and line it with plastic tubeing 1/2"ish tubing put like 100 ft under ground and dont use a tank. Thats always how iv seen it done, also I dont think you have to go all the way to 10 ft but it would probly help.

 

[FireEater]

Stand up and take a look at your standard ceiling height. It is 8 feet high so you will have to dig two more feet than that. Ten feet is deeper than one thinks when it comes to dirt.

You just don't dig a hole ten feet down by shovel. You will need a backhoe and wall supports and plenty of room for lot's of dirt.

 

[Ulric]

Just try going 3-5' deep... you'd get more, variation in ground temp. I can't imagine it being all that much though.

I think, using a container vs lines would probably be better. More, water/surface area to lose heat from... but as other said, more potential problems.

Also to consider, your effective volume to skim etc changes. Containment can become an issue in regards to weight on the containers etc... ease of access to pump in case of failure, etc ,etc.

....wonder how well it might work if one utilized a concrete septic tank as an overflow/cooling system.

 

[R-BallJunkie]

nice ideas, but far fetched. you are thinking thermal energy storage. i dont suggest digging a 10' hole in houston, water table etc, contamination, servicability etc. if you wanted to expend energy and resources, you might want an intermediate heat exchanger of some sorts that you could transfer "cool" from, lessening the load on your chiller. but this would require a free standing SS or titanium HX to draw from on a circulatory basis.
the source could be a tap in loop from main air conditioner of house....just thinking out loud here.


alternately, you could buy a more efficient chiller and the problem would go away

 

[Guest]

Ok, this is out there

I've also wondered about this. This wouldn't chill as well, but would avoid contamination. What about putting a container (sump) on the surface attached to your buried sump. Actually flood the upper sump with water, but have the downhold portion be a container filled with 1/2" tubing. The water would circulate through the lower container slowly (and presumably cool) then return to the upper sump where it is dumped, then drained to circulate. In the upper sump run 1/2" line from the tank through the water in coils to cool and return to the tank.

You could still have problems with the whole downhole process, but contamination of the tank would not be one of them. Also it would reduce the volume of skim water etc.

If it works, I wanna know.

 

[NeoTheWicked]

This idea your talking about is used alot in air conditioning up north in place of using a standard condensing unit. It's called a field loop. It can work to do what your wanting but the aspect of sending saltwater thru the line concerns me. You would be able to use distilled water or a liquid coolant with rust inhibitors. The heat exchanger idea is well thought up as long as you do it right. If you go this route after the hole is dug fill the area around your pipe with sand to allow for expansion also roots are something to be concerned about. Just think it out real good and it should work fine. And you should'nt have to bury a large container just run out and back a few times and you should get a nice drop in temp.

 

[toan]

i just think it would be more costly... not only constructing the piping underneath and digging and what not but having a pump to constanly run and it would need to be a powerful one,, that will run all the time,

im pretty sure everyone has come to the idea that this isnt feasible or even reasonable

theres other methods of cooling a tank

 

[Ulric]

Where there is a will, there is a way....


...and part of the fun, can be epxerimentation.

 

[lesd]

I saw a thread a while back where a guy named Rocky in Florida (handle was ScubaDude) did this for his Greenhouse coral farm.

He buried about 100 ft. of thin wall PVC in trenches and it worked like a champ. Maybe someone who is skilled at searches can find the thread.

-- Les

 

[toan]

yea but wasnt he like a commercial propagator?

i think the purpose of his greenhouse was so that he could have a bunch of tanks using sunlight to grow

 

[BayAreaAquarium]

could you do this:

place a contain filled with saltwater (to lower the freezing point) in the ground. drill two holes the size of the tubing that your going to use. place about 100 or more feet of the tubing inside the container. place a pump on the in going side of the tube (above ground) and have it on a timer so that every 15 mins or so it pumps the water that has been chilling in the container below to where you want it to go.

with that you don't have the risk of cantamination and because the water sits in cooled water it will cool down pretty quickly.

 

[Guest]

In time I would think that the saltwater in the container would corrode the container. Also, the two holes for the tubing are just one more weak link in the chain of events......
All in all, good ideas, but this is something that would really have to be thought out and planned, down to every detail, including the seasons...

 

[dfimble]

10 feet down really didn't seem like such a large amount until someone put it in perspective of digging a hole as deep as the room.

I do like the idea of putting in long line of thin PVC. I think the best thing for me at the moment is to wait until after the summer months are over and see how hot my 1 gal container buried 3 ft gets. Then see what happens.

I love all the different ideas! Thanks!

David

 

[scottk]

The whole deal is to save money on utilities. If you had the perfect situation (like the farmer on RC) you could use the sun for lights (greenhouse) and use the ground for cooling (geothermic cooler out of PVC pipe) and save lots of money. It works but the setup could be expensive and Texas isn't Florida (where the farmer was). I would think our summers and heat would make it tough.

That being said, if I had the space and a greenhouse, I would try it....lol.