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. The electrical energy usage would be shown for any days when the electric heater was used, but it was not needed this month.
During the month of July, the temperature of the air entering the coop through the vent began to exceed the temperature of the outdoor air by such an extent that I had to upgrade the ventilation system. If I had not taken such action, the biomeiler would have begun heating the coop above the outdoor temperatures. The change in the system allowed for the coop to receive air from a shaded area. Later, I finished the upgrade by arranging for the ventilation pipe to draw air from beneath the coop.
In the image, you can see that the pipe has been buried. The coop sits on three lines of railroad ties. So, by burying the end of the pipe and filling in the gap between the two nearest ties, I ensure that fresh air enters from the open space at the far end and must travel across the cool ground for the full length of the coop.
The ground beneath the coop, cooled during the winter months and sheltered during the summer, is the coldest region readily accessible. Air passing over that ground is, by convenient circumstance, the coolest possible air that might be brought into the coop during the summer.
On the graph, the line representing the vent pipe temperatures ends on the 13th. The thermocouple that measures it cannot easily be repositioned to monitor the air coming through the new ductwork.
The “geothermally cooled” air enters the coop at approximately 63F. This airflow is helpful, being perceptibly cooler than the outdoor air, but is not not sufficiently cold to prevent the coop from sometimes reaching temperatures in the 80s. Fortunately, the heat of the summer is near its end. The weather in Fairbanks typically cools at the end of July, with only occasional hot days in August and September.
On July 28th, we left for a vacation and had to discontinue the readings.
This was just what I needed. Thank you for explaining it so clearly!
I am glad to hear this helps someone!