Geothermal heated waterer
 

Lately I've been thinking of using the heat of the earth to keep the water for my geese free of ice.

My plan is to put an insulated box over a hole that I've dug with a posthole digger. The box will have a hole just large enough to set a bucket into the box. Then I'll bank the area with straw to keep it from freezing. The high water table (2'-3' from ground level) keeps that area from freezing very deep so if I dig deep enough to hit water there should be a lot of free heat. I've dug there with a shovel in the middle of the winter when the rest of my property is frozen 3-4' deep so I'm pretty confident there's lots of heat. At the time it was insulated by snow.

Can you think of anything to watch out for?

It should be an interesting project. Please be sure to keep us informed of success.

Quite a number of years ago I was told some farmers bury an old culvert upright and then place a stock tank on top of it. The warm air in the buried culvert rises and keeps the stock tank water from freezing. That wouldn't work at all in a high water table area however.

Here's a photo of the area where the waterer is going. You can see the size of the area that will be insulated by straw. I'll be piling the straw about a foot.

http://i121.photobucket.com/albums/o...scovies001.jpg

Here's a photo of the pipe I put down. The pipe is a scrap piece of 3" with a 4" adapter on the top. It's goes about 5' down and there is water in the bottom of the pipe.

http://i121.photobucket.com/albums/o...scovies002.jpg

Next I'm going to build a small plywood box and insulate it with 2" of blue foam. I'll add an extension on the pipe so that it comes up near the bottom of the bucket so that I can pack the rest of the box full of straw. I'm also going to bank the outside of the box with straw. I've got some scraps of pond liner so I'll put that on top of the box and over some of the straw so the geese can't splash too much water on the straw around the box and ruin the insulating qualities.

I'll add more photos as I get more done.

I have a frost free Freedom Fountain that works just like you say.

It is fed by a water pipe laid below the frost line. There's a hole about 16" diameter down about 2 feet. There's a styrofoam liner that fits the hole. I poured a concrete pad with the styrofoam tube in the center. Then set the waterer on the pad. The heat rising up the insulated tube keeps the water from freezing. In the top of the water tank are two large balls that the cows and goats push down to drink. At other times, the balls seal the top of the tank.

There's a valve with a float rod in it that looks just like the float valve in a toilet.

I've had mine for 4 years now and it's never frozen.

Here's the link to the new ones:

http://www.behlencountry.com/cattle/...free_waterers/

They've replaced the styrofoam tube with a smaller poly tube, but otherwise looks the same.

Genebo

I thought of another design that might work on my higher ground. A person could jet in a 1-1/2" dry well 10-15' deep. Then seal the bottom so that it holds water. Then sit the waterer over the well and connect the well to the bottom of the waterer so that when the water cools it drops down into the dry well and warms up. That should cause the water to slowly circulate. I think it would work provided you don't lose too many btu's in the tank because there's a lot of heat in the ground.

We expect a 4' frost line and now that we are in drought and we don't have the snow cover our frost has gone down 6-8'. That would require insulating the ground around the waterer.

Hi,
I guess the cows/goats don't have a problem figuring out that they need to push the ball down?
Are the balls weighted so that it does not take much force to press them down?

I'm building a new solar heated tank for my neighbor, and wondering if this ball arrangement could be used to keep surface ice from forming. This would be for horses.

Gary

Gary,

What about using a spring loaded semi-vertical door like you find on some indoor trash cans?

SolarGary,

Cattle and goats figure it out almost immediately. I think they can smell the water inside.

The balls are not weighted, although there's a tip in the instruction manual that says for sheep you can add a little weight to make the balls easier to push down. I don't have any horses, but a friend has donkeys that drink out of his.

Genebo

fishhead, we have designed a couple different livestock tanks using the idea you have, with good results. It's absolutely necessary to block off all air leaks and to insulate well, of course. We really don't like running tank heaters for our horses and cows, so we try different ways to keep our tanks ice-free.

We've also used manure as an insulator with moderate success (build a box around the tank, fill the gap with composting manure).

This year we are trying a new design inspired by Gary's solar heated tank. Rather than building the entire tank, we enclosed a metal stock tank, painted black, in an insulated box with a clear panel on the south-facing side.

We added a fence panel to help protect the solar panel from the horses, but still allow light to reach the tank.

We put these out two nights ago--we've had overnight temps in the upper teens to low 20's and had only a verrrry thin skim of ice in the morning. This is in comparison to the 2-4 inches that we had with unprotected tanks.

The tanks are partially covered but do remain open at all times. If we added some type of floating cover on the water itself, I don't think we'd have any ice. The horses, however, would pull out anything we put in the tanks.

I'm building one of those solar heated ones myself. Stuff changes too often around here to put holes in the ground.

Out in the feedlots we bought this year they had the ground heated ones and they worked pretty well from what I gather.

Here’s an underside shot of the insulated bucket stand.

http://i121.photobucket.com/albums/o...terer08001.jpg

Here’s the stand in place.

http://i121.photobucket.com/albums/o...terer08006.jpg

Here’s a view of the heating pipe through the bucket hole..

http://i121.photobucket.com/albums/o...terer08008.jpg

Here’s a view of everything in place. I’m going to add a piece of pond liner to move the spilled water away so that it doesn’t wet the straw next to the stand.

http://i121.photobucket.com/albums/o...terer08010.jpg

FAILED!

A measly 12 degrees F this morning and it was already frozen over. I think there is too much exposed surface.

How much water is in the bucket (I mean, what size is the bucket) ? You might need to have more water--as the top of the water cools, the warmer water at the bottom circulate to the top, and the cooler water should circulate to the bottom to be warmed again.

I would: increase the water volume and decrease the exposed surface of the water.

I think the bucket is about 2 gallons.

I just looked at it again and I see ridges that keep the bucket from sealing the hole it sits in so I'm going to try to fix that first. When I got back from the farm this morning the water was open even though the air temp was in the 20's. This morning I added about 3" of water on top of the ice.

If that doesn't work I'm going to add a piece of 1 1/2" pvc pipe to the bottom of the bucket. That pipe will be slide into the 3" pipe that is in the ground. The water in the bucket will then go all the way into the ground. I'll also cap off the "outside" pipe shown in the picture so that it doesn't allow the heat of the earth to escape. That should allow the water in the bucket to circulate into the ground to pick up heat and then rise back into the bucket.

I'm also going to have put a cover over part of the bucket to hold more heat.

Fishhead,

Instead of the pond liner, try coarse gravel. The animals don't like standing or walking on the gravel, so they'll get a drink and leave. I'd fill dirt all around the enclosure and then put down the gravel.

I have it around my waterer and it stays in perfect shape all year.

Your tube looks small for the amount of air you want to circulate. Try making a heat exchanger from some copper tubing. Double it to extend down in the hole, into the water. Then make a coil out of it like an electric stove burner. Let the coil touch the bottom of your bucket. This should bring more heat up to the bucket. Especially if you can fill the copper tubing with water and pinch the ends shut.

Can you put a thermometer in the enclosure? It should read above freezing. If you have one of those wireless indoor/outdoor thermometers, put the outdoor sending unit in there. You can monitor it from inside where it's warm.

Genebo

Today I cut strips of pipe insulation and tucked it under the rim of the bucket to make a seal between the bucket and the top of the box. The temp is in the low 20's and the water is still open. We'll see if it stays that way tonight.

I'll get a temp on the air in the box next weekend. I also need to figure out a way to keep the insulating straw dry and fluffy so the ground doesn't freeze near the pipe. Since we are in drought the water table has dropped to about 5'. It used to be 2' and I think that is what kept the ground from freezing.

Nope. It's a failure! Possibly if I used a larger pipe it might work but winter is here to stay so I ran an extension cord down to the pen and put a 100 watt bulb inside a metal can to prevent spilled water from busting the bulb. The water stays open now. I'm switching to a 60 watt to see if that puts out enough heat.

Howdy. Tried digging up the pipe and all, and just sinking your entire insulated box into the earth so that the entire bottom of the tub is exposed to the warmer water underneath? The top of your box would be flush with the earth then, your tub would be actually below ground at bottom, and you'd have a 6-inch (typical post hole digger) hole completely open down to the liquid water in the ground, allowing max heat transfer upward. Perhaps this way you would be using the insulating power of the earth, plus the radiant heat from the water.

I hate to give up til all is lost! I think you are maybe on the correct track, it is just that your heat exposure through the small pipe is not adequate, and is being overcome by the box sitting up in the cold air.

Me again. Here's a guy who used expanding foam...

http://www.ibiblio.org/farming-conne...s/builtank.htm

Don't give up yet!

Winter just arrived so it's game over for this fall.

If I try it next year I think I'll try that plus extending the box all the way down to let more heat or maybe water jetting a 4" pvc pipe well into the water table. If I do the latter I'll plumb a piece of 2" pvc pipe to the bottom of the bucket. That way the water in the bucket will be sitting in the water in the ground with just a layer of pvc between the 2. As the water cools it should drop down to the bottom of the tube and pick up heat from the groundwater and return to the surface. I think if it's sitting in 2' of water that should be enough to keep it from freezing.

Fishhead, most likely you know that water is heaviest at about 39 deg F, and that might figure in how you set up the waterer. Also...are you familiar with heat pipes?

Don't give up yet. If you can't sink the waterer down into the ground, bring the ground up to the waterer. Mound dirt up flush with the top of the waterer. Pack it down so that it becomes one with the ground. That will bring ground heat up. Your straw insulation is holding the ground heat down in the ground.

Genebo

What about putting a thick lining of sawdust under the water tank? Sawdust creates its own heat. I wonder if it would be enough heat to keep the water from freezing?

Hi,
Is this still working out OK?
Some pictures would be great :)

You could start a new post on it so as not to interfere with Fishhead's design.

I'm building one for my neighbor -- we decided on the same kind of arrangement with her galvanized tank as the base, and in insulating shell around it.

Fishhead -- Just a thought, but I think you need a way to conduct more heat up through the pipe, and then from the pipe into the bucket. Maybe 1) something more conductive than the PVC pipe -- e.g. steel pipe? with insulation around it so that the heat that is transferred up the pipe is not lost out the sides before it gets up to the bucket. 2) more heat transfer area from the top of the pipe to the bucket. It seems like you have a heat transfer bottleneck where the top of the pipe contacts the bottom of the plastic bucket. If you could weld a (say) 10 inch diameter metal disk to the top of the steel pipe, so that the whole bottom of the bucket contacted the disk? With insulation under the metal disk?

Update at 8:30 -- Just trying to put some numbers to this. If instead of the PVC pipe you used a solid cylinder of aluminum 3 inches in diameter, and the water table water is a 50F, and the bucket is just above freezing, and the aluminum cylinder goes down 4 ft and is insulated on the sides, then the heat conducted up the aluminum would be about 25 BTU per hour. This would be enough to warm 2 gallons about 2F per hour -- so if the cool down rate in the bucket is less than 2F per hour, this would keep up with it.
The PVC pipe is well over a hundred times less conductive than the aluminum, so I don't think you can conduct a useful amount of heat up the PVC -- I think you need a much better conduction path from the water table water to the bucket.
All assuming I did the math right and I'm not missing something :)



Gary

The temp of the ground should be in the 40's at least and if I could tap into it the heat would be basically unlimited as long as it wasn't withdrawn too fast. I think it would warm the water above 39 degrees and cause it to rise. If not I'll end up with a 5' icycle.

The way it was originally set up the pipe stopped at ground level and the pail sat about 10" above that so the heat should have been able to contact most of the outside of the pail.

Great idea, Fishhead, even if it didn't work so well on the first round. Keep at it! (The things we do for our geese!)

Just pound some steel rod into the ground under the bucket. a peice of old railroad rail maybe?

I can't seem to be able to find the stock waterers that I saw last year. Basic plan was to dig a 6'-9' deep hole, and put a closed pipe inside. Pipe was large, maybe 18" diameter.

... ok, found something similar...
http://www.cobett.com/faq.html

Much larger scale than what you are doing. for yours, I would build an insulated box to sit over the pan of water. Use the reflective bubble insulation on the inside. Only leave an opening large enough for one goose to get through.

Too late this year, but I want to try the following, and see if it works:
dig a hole 8' deep and bury the largest diameter pipe I can get. Close off the bottom, so its water tight. Dig around the hole, and put a layer of extruded polystyrene foam down. Insulate the pipe down to the frost line, and seal the foam to the pipe insulation. Backfill above the foam, and leave the pipe sticking 6" out of the ground. Fit a pan so it fits into the pipe, and fill the pipe with water.

The water in the pipe should create a thermosiphon to pump the heat out of the hole, and keep the water pan warm. The horizontal insulation will keep the soil around the pipe warmer, so you have more heat available. The larger diameter and using water may make it successful. Don't know if it would work or not ...

Michael

It sounds like a better design that what I tried.