Thoughts: How to keep water unfrozen in winter outside

Have the horses carry water. Their body temp will keep the water unfrozen.

 

I'm not familiar with this equation, but if U is the inverse of R, shouldn't the .04 for the Ceiling be .05 and shouldn't the .04 for the Floor be .10?

Also, is the Delta T 1 or 32?

 

R is the resistance to heat flow through a material.
U is the calculated rate of heat flow through a material.

Therefore a higher R-value/Lower U-value means less heat loss.

U-value are the number of btus (or fractions of btus) that will pass through the material in 1 hour, with a 1 degree F Delta T.

As for the U values I chose, I was using an old solar engineering text, and used simple styrofoam enclosure, but my book didn't include specific structure so I guess a bit as I suggested in the original post.

I hope this helps.

 

Water has high specific heat (amount of energy required to raise 1 gram of water 1 degree Celsius) and is resistant to temperature change. One sure thing: insulate the tank, either in or above ground. Cover one-half of the tank to avoid heat loss to the atmosphere. Take every advantage of passive solar gain (a south-facing window in the barn wall?). Small quantities of water are more prone to freezing than very large quantities. Run supply lines through the soil (insulation + geothermal heat). Use a stock water valve that is resistant to freezing. Insulate anything above ground (tank, pipes, etc.). Protect pipes and tank from wind (sucks heat energy away). Some stock tanks use a small circulating pump to keep water from freezing.

 

A couple of large hydration packs each should do the trick. All you'd have to do is teach the horses not to chew off the bite valves....

 

Yes it does. It's very common for gardeners to put "water skirts" around new plantings to prevent frost damage. The skirts sit about a foot high and provides enough of a block to make a real difference.

Also, you will have to occasionally dump and clean the water barrel, so make sure that whatever is made (if anything) is removable.

 

If you took a tank, and for example, sunk 8' of it in the ground, insulated the hell out of the two feet sticking up, top and sides, and left the in ground sections exposed to soil, perhaps insulting 2' down, the thing would never freeze, certainly no more than surface skim on the top.

 

As the less-than-proud owner of a ground-source heat pump, let me respectfully disagree. The low conductivity (?) of dry soil is why you need 1000's of feet of pipe for the typical ground source heat pump install.

If I read the numbers right (big if), if soil is 55 F and water is (say) 35 F, you get energy flow of something like 3 watts per square yard of soil exposure.

Barrel, couple of feet across, 8 feet down, I'm figuring 21 watts heat flow. I think that's the margin you have to work with. Will 20 watts keep the tank ice-free?

 

When I say never freeze, I assume that the vessel is insulated from the air as much as possible, and there is some change of water per day as suggested above.

It is a long way from a ground source heat pump trying to get to a temp ~70f out of the ground than to keep a vessel from freezing in 50F earth and 0F.

Icarus

 

Let me try that again. I'd test whether or not the heat input is going to be enough before I went to the trouble of digging the hole.

My guesstimate is 20 watts. I see (e.g.) birdbath heaters in the 40 watt range. If I did the arithmetic right, 20 watts is enough to keep a 32 F difference across 50 sq ft of R-40 wall. Or across less than 2 sq ft of R1 wall.

So either looking at what's for sale or doing the arithmetic, it doesn't strike me that 20 watts in an insulated barrel is a non-starter. Might work might not. Certainly less than any commercial stock tank heater.

If 20 would do it, a car battery would last a couple of days. Then its a question of whether you'd rather dig a hole or tote a battery.

EDITS: Or I can just apply Halvorson's Law: Anything you've thought of, somebody else already thought of it and put it on the internet.

75 gallon insulated stock tank with ground-source heat to keep it unfrozen:

http://www.cleanenergyresourceteams.org/files/CS_Geothermal_Azariah.pdf

Here's a whole list of them:

http://www.builditsolar.com/Projects/WaterHeating/water_heating.htm#Animals

And here's your basic battery-powered stock tank heater:

http://www.hydrogenappliances.com/stocktankheater.html

There are plenty of worked-out examples to choose from.

 

I've been reading the posts in this thread and giving it some thought. So far everyone has missed the obvious solution: Live in a warm climate.

Just thought I would help.



Tom

 

Regardless of the facts (LOL), I think a stock tank, inside a barn, in a well insulated enclosure, with a fair percentage of the water exchanged each day, will in all likely hood not freeze if protected from the wind in temperatures near 0F! (in a day!) Even if it were to freeze, it wouldn't freeze solid until at least a week or so passes.

Pretty simple, buy a 100 gallon plastic or galvanized stock tank, build an insulated box around it, and try it. Net cost,, a couple of hundred bucks.

Like I said earlier, my hot tub, sitting on the ice, exposed to the wind at temps -20F or colder over night will not begin to freeze(with no fire) for several days. I think there is a real risk of over thinking this. As Chogan says, somebody some where has done it,, twice and posted on the web.

Icarus