The temperatures in the biomeiler pile are measured with thermocouples buried in several locations. Nine of them are found at three heights (1’, 2’, and 3’ above the ground) in the inner core, outer core, and mantle of the pile. The graph in today’s post shows the temperatures measured by thermocouples at 3’ height. These sensors are buried 1’ below the upper surface of the pile. A sheet of Reflectix, a tarp, and some snow lie above the top of the pile.
In this picture, you can observe that the surface of the pile has fissures and shows evidence of subsidence. There are elevated rings over the fencing surrounding the inner and outer cores. At the perimeter, the pile has dropped 7-9” below its original height.
My recent exploration indicates that the ice cap has entirely melted away. The holes seen in the image were dug at the boundaries of the inner core and outer core. I dug a handspan below the level of the wire fencing and discovered the material at that depth was noticeably warmer than the air temperature. These observations lead me to suspect that anaerobic composting has been rekindled in the upper levels of the pile.
The temperature of the pile decreases with greater depth, which is likely due to the cold water running downwards from the melting ice cap, cooling the lower materials, while the upper materials are absorbing heat from the outdoor air. I predict that, as time passes, the heat in the upper levels will conduct downwards and raise the temperature of the deeper materials to a degree at which composting might resume.
While the cooling effect persists, I will leave the pile intact to continue making use of the ventilation system as it is. However, if conditions change to the point that the incoming air is warmed by the biomeiler I will disconnect the duct fan that pulls air through the vent pipe. The duct fan that pulls air out of the coop can continue running and air coming through the window will replace what was coming in through the vent pipe.
Until then, I will continue collecting data to document the full extent of this unanticipated bonus from the biomeiler.
You’ll figure out next steps, I’m sure, as you monitor so carefully and adjust the conditions accordingly.