Insulating the Sand Bed

Before pouring in the sand and laying down the tubing, the bottom and the sides of the trench need to be insulated. This prevents most of the heat from escaping into the ground and allowing the majority of the heat to finds its way into the house through the concrete floor. It was decided that two inches of foam board (equivalent to R-10) would be adequate for our project. The dilemma was how to fit rectangular (4′ x 8′) sheets into a circular trench.

Tom, a friend I met at the solar hydronic heating seminar earlier in the spring, gave me a hand in figuring out the pattern for the foam board and cutting lots of triangles. Our goal was to have as little waste as possible. After deliberating various ideas, we decided to experiment with one board by cutting it into three triangles. And low and behold, the puzzle pieces came together with hardly any waste at all. We found that two to three triangles next to a full sheet (4′ x 8′) board worked great! We were able to use the combination all the way around the trench until we got to the last piece.

Although, Styrofoam is a non-natural building product, I don’t know of anything better to put under a floor to keep it insulated from the earth below. It would be great to build a house entirely of natural resources, but if I also want the house to be as energy efficient as possible, there has to be some tradeoffs.

The next step will be to build the Styrofoam sides to the trench, but I won’t be able to get to that for a couple of weeks. Next weekend is the Midwest Renewable Energy Fair and I wouldn’t miss that for the world.

This spring has had all sorts of weather surprises so far. March and April were incredibly dry months and then came May. As I had mentioned earlier, somebody turned the faucet on and there were two episodes of torrential rains that hit SE Minnesota. The Root River which runs through the valley below us, became a lake as more than 6 inches of rain fell in an area that feeds into the Root River. The Root River turned the low lands into one big lake. (The photo above was taken in the evening that we arrived, so it’s a little dark. If you look closely you can see one of the farms under water.)

Farm fields were completely underwater and farmers were literally trying to save their livestock as the floated on down towards the Mississippi. Thankfully, no one was seriously injured. It was just incredible to see what was once a fertile valley, completely submerged.

Birds of a Feather
Finally, a new Beanie-Baby photo… Here’s a photo of four baby phoebes that were born and raised right under the eve of our cabin porch. Phoebes make great bug zappers and require no electricity.