geothermal

As I wrote last time, we hope to control the sow's behavior in her pen in our new farrowing house by varying the temperature of the floor.  We started by installing plastic pipes on urethane insulation under the concrete.  As you can see in the first two pictures fourteen of these "loops" were installed under what would be the center of the pen, from about four feet inward from the gutter end to eight and one half feet, a total span of about four and one half feet.  This is where we expect the sow to nest up and have her piglets, with the guard rails adjacent and the water cup and dunging area in the four feet next to the gutter end, and the feed bowl and piglet creep area in the three feet at the pen's front.  See the pen pictures in the last post.  Through these fourteen loops of pipe we will pump cool water in summer and warm water in winter.  You can also see in these pipe pictures that we have installed a curving set of four pipes right near the very front of the pen.  These pipes will circulate warm water all year long, to tempt the piglets away from the sow to the warmer parts of the floor.

We have dug a geothermal supply trench west of the barn to a depth of twelve feet(see picture)  This was deep enough so that we got water in the bottom even in the very dry fall of 2012.  This trench was dug out five hundred feet from the barn at twelve feet and then those five supply pipes were folded back and run back toward the barn at a depth of eight feet.  This gives about 1000 feet of total collection area.  Now ground temperature at those depths is going to hover around 45 or 50 degrees winter and summer.  By pumping water through those pipes, we can chill it to that temperature in summer and then pump it through the cooling grid of under floor pipes to bring the sow a cooling effect and make her comfortable enough to want to lay quietly with her piglets.  Then in winter, plans are to run warm water through the same pipes to increase her comfort in that area while we keep the remainder of the building quite cool.  For now plans are to use a gas fired boiler to provide hot water for the floor under the sow in winter and under the piglets year around.  Very soon we plan to tie a good solar thermal panel into that system to minimize the amount of gas needed.

Meanwhile, in winter, we will continue to use the geo thermal trench, but now we will use the temperature which may be at 50 or 55 degrees at start of winter, to preheat the intake ventilation air so that the heating needs in the building will be minimized.  We do not have this part of the system settled in our minds yet and it will be some time before we have it in use.  The final picture is to give an idea of how we have tied the new building into the existing barn, getting a good second use out of the barn for a utilities and prep area, plus bedding and feed storage.   

Farrowing house and pens.

Our new farrowing house is in use.  The reasoning for building it, as any of you who have followed this writing for a while know, is that pasture farrowing simply could not provide the flow of pigs we needed to provide the pork for our customers on a year around basis.  So when we began to plan the building, we resolved to make it mimic the pasture environment as well as we could.  Thus the ceilings are a full eight feet in height, rather than the conventional six and a half.  We have four large windows on the south side and two plus a window in the door on the east end.  During daylight hours the light is wonderful in the building.  The pens are roomy as you can see in the photos.  We were able to reuse some of the steel and plastic planking from purchases made at a shut down hog farm.  Our choice was for the plastic because like wood it is quieter than steel in a hog building, but unlike wood, it stands up well to chewing by the sows and it is easier to clean, always a consideration when livestock are kept inside. The effect is an inviting and quiet environment in which to do our work.  The sows are comfortable as well;  the first group to be moved in settled right down in their pens and soon farrowed their litters without a  hitch.

Note the diagonal guard rails in the front of the pen.  These were made from a farrowing crate with the top taken off and the sides spread out.  The pen is about six feet wide and eleven feet deep.  The sow has her drinking cup toward the back and a grate through which she might see and interact with the sow next to her.  Our hope is that she will establish a dunging and wet area back along that end gate as it has the gutter and cleaner just on the other side.  Then the center and front of the pen would be bedded for her comfort and the guard rails allow the piglets to be next to her without being in much danger of being overlain.  Part of the way in which this is meant to work is that the floor will be temperature controlled by zone which will help control the behavior and movement of the sow.

The floor slopes down one inch each three and one half feet of run toward the far end of the pen.  This is approximately a two percent slope, which is not steep by any means.  Time will tell if we will need to use a bedding board across the pen to retain the straw in the front of the pen, or if the sow will be able to do that herself.  We really will not know until we get the geothermal and heat up and running.  As you can see, the two sows in the picture are lying near the bottom of the pens with their litters.  We hope to discourage that.  More on this in the next post.