The biomeiler continues to steadily cool the incoming air, but the effect is diminishing. There were a few times this month when the coop was actually cooler than the outdoors, but the fall season has begun and, thus, the outdoor air temperature is dropping. The data are shown in the main image of this post.
The air entering through the vent is still colder than the outdoor air, but the coop is now clearly warmer than the outdoor air. It is not a problem because we like to have the coop temperature stay in the 60sF and that will eventually require additional heat.
The second chart shows the temperatures measured in the biomeiler at a height of 4’ above the ground. This height marks the boundary between the pre-existing biomeiler and the recent extension. The data were collected by a thermocouple buried in the pile at that height at the very center of the inner core, another placed halfway between the inner and outer walls of the outer core, and a third similarly placed between the inner and outer walls of the mantle. The air temperature was measured on a thermometer in the open air.
The biomeiler is warming up while the outdoor air is cooling off. So, the temperature trends are difficult to describe. Overall, the inner core appears to be warming up slowly and the outer core is warming more quickly. The mantle does not generate heat so its temperature trend is a combination of the outdoor air temperature and the outer core temperature. As these trends continue, I hope to see the four lines arranged in the opposite order they were in at the start of the month.
I have decided to attempt a second refueling of the biomeiler in the hope of achieving a third winter of continuous operation. That being the plan, in the next few days I will uncover the biomeiler and begin adding used litter from the coop and plant material from the field.
The pile has settled to the point that it will require a substantial volume to restore the surface to level and replace the peak it had at the start of the winter. In all likelihood, this will be the last refueling possible. The composting process can reduce the volume of the materials, but the pile will eventually become filled with non-reducible material and a full rebuild will be required.
I’ll be sure to document the refueling process in upcoming posts. Stay tuned!
