The outer core was assembled in almost the same manner as the inner core. The inner core has an 18” radius, while the outer core has a 36” radius. Thus, the outer core has twice the circumference and three times the volume of the inner core.
The PEX pipe was wrapped around the outer in a downward spiral. I used 136’ of pipe to make about 8 loops. I wanted the input and output ends of the pipe to be at the same at the same elevation as the ventilation pipe, which will be added later. The reasoning behind this choice will be described in a later post.
Thermocouples were added to the outer core at heights of 1’, 2’, and 3’ at about 2’ in radius. The distribution hoses from the aeration manifold reach to the perimeter of the outer core, plus or minus a few inches.
