Freedom's Solar Stock Tank

This is Freedom's solar heated and well insulated stock watering tank.  The combination of good insulation and solar gain through the solar collector built into the south wall of the tank should eliminate or greatly reduce any need for heating the tank during the winter.  Freedom lives in Michigan's Upper Peninsula, so this should be quite a good test.

 

This is similar to the prototype I did last year, and it will be great to see how well it works out in actual use.  I will pass on how the tank does through the winter as Freedom sends in report.

 

Thanks very much to Freedom for providing this material!

 

Freedom's description of the tank:

 

Hi Gary:
 
We have completed the box and it is ready to go for this winter. We typically get 300 inches of snow and temperatures well below zero for most of the winter. I have triple insulated the inside with foam board insulation, 3 inches thick on back and sides. I used spray foam insulation to heavily insulated all joints of the box as well. I got the clear twin wall polycarbonate for the front. So it's insulated to the hilt and the top is painted black to help keep ice off the top. The top of the box features a drinking hole. The collector portion is sealed off before the top is put on. I used 20 mil pond liner in the tank side. I'll include the materials list here as well....with lots of pictures. I just wanted to say that I am a NOVICE person and a female at that and I found this very easy to construct. Thanks so much for this wonderful idea. I will be recording the weather and the performance of the box over the winter. I'll send this along come spring. The box measures 45"X33". (holds a lot of water)
 

 

Update for Nov 1, 2008:

I will keep you updated on the performance of the tank. Last week it got down to 18 degrees during the night. In the morning, everything was frozen outside, but not the water in my tank. :) Let's keep our fingers crossed when it's -30. Thanks again for the great idea. My horses are adjusting quite nicely to it and they seem to enjoy it so far. I'll be in touch every so often throughout the winter. We are also going to be adding a soccer ball to the water once it gets super cold. I am hoping this will completely fend off the ice.
Freedom

Click on pictures for full size


The basic 2X4 framework for the tank


Framework with OSB sides.
The setback side will become the
collector absorber.
Be sure that the frame supports the
vertical edges of all the sides.

 

 


Another view of box showing the
collector bay.


The OSB side that will be the
absorber for the collector
painted black to absorb sun.

 

 


The box with the first layer of rigid foam
board insulation installed.
Note the use of the polyurethane foam
in a can "Great Stuff" to seal
the boards in place, and close gaps.


The box with the 2nd layer of blue foam
board installed.
Three inches of insulation were used in all.

 

 

 


The liner.
It looks like Freedom used the nails with
the large, plastic heads to hold the lining
in place --  this seems like a good choice.


Box with liner installed, but not yet
trimmed.
The liner is 20 mil PVC pond liner.

 


The tank with the lid installed from
from the back.  The opening for drinking
should be as small as the horses
will accept in order to keep the
heat losses down.


The finished tank with the collector glazing
installed.  This is twinwall polycarbonate
glazing.  This is a good glazing choice
because it is very tough, and its two
separate layers reduce heat loss much
like double glazed windows on a house.

 

MATERIALS:
 
3- 4x8' SHEETS OSB, TREATED
3- 1' THICK FOAM BOARD INSULATION
1- 10x10' 20 MIL POND LINER
4- CANS SPRAY FOAM INSULATION
3-CANS BLACK SPRAY PAINT, SATIN FINISH
1-45x33' CLEAR TWIN-WALL POLYCARBONATE
7- 8' 2x4'S, TREATED WOOD
2LB. SCREWS (1# 3 INCH, 1' 1 1/2 INCH)
16- TAPERED HEAD SCREWS (1 1/4') WITH NEOPRENE WASHERS (TO ATTACH POLYCARBONATE)
 
TOTAL COST: APPROX $171       TOTAL CONSTRUCTION TIME (BY ONE PERSON, NOVICE): 24 HRS
 

Freedom Brunel

October 30, 2008

 

Freedom will answer email questions at:  demongelding1 AT hotmail DOT com  (change AT to @ and DOT to a period)

 

 

The only small comments I would offer are:

- It might be good to add a floating lid of insulation board with a drinking opening in it to further reduce heat loss from the open water surface.  If the horses would tolerate it and not eat it.  Mark has suggested the possibility of using ping-pong balls as a floating lid if the horses could learn to drink through the balls and not eat them.  But, the tank may do fine without any additional lid insulation.

 

- A couple coats of paint  on the OSB would probably increase the life.

I'm really curious to find out how well the tank does over the winter.

 

Note that for some people I have heard from the payback period on the $170 would be less than 2 months of winter heating bills!  Even less when you consider you have to have some kind of tank anyway.
 

 

Gary, October 30, 2008