The graph shows the temperature in the chicken coop, the temperature of the air in the vent pipe coming from the biomeiler, and the temperature of the outdoor air. On the same graph, I added the electrical energy usage for the days when I had to use the electric heater. The scale is the same, but the units are in kWh
The air vent temperature was relatively stable this month. The range of temperatures was 32 to 41F. I speculate that the air vent temperature is moderated by the latent heat of the water in the mantle layer of the pile. If the outdoor air gets cold enough to freeze the nearby water, the water would have to release heat, which would warm the air vent. Heat moving outward from the inner core and outer core would replace that heat and melt any ice, allowing the air vent to stay above freezing.
In general, the coop temperature followed the trend of the outdoor air temperature, but was moderated by the steady addition of heat from the air vent and the steady addition of body heat from the chickens. So, the temperature generally stayed in my chosen range of 45F +/-10. When the coop temperature dropped too far below the chosen range, I used the electric heater to warm it up. This month, the total usage was 14.68 kWh, which cost about $4.55.
In a future post, I will discuss the temperature data collected from within the pile.
Magnificent graph. I understand what you wrote, except the part of freezing water releasing heat. To see the information on the graph, however, helped me transform the written word through the visual graph. Between the two, I think I’m understanding the information.
Your visuals always seem to be just what I need to augment what you have written, so they are much appreciated.