(continues from previous post).
I made up a frame to easily stack and hold inside the sheets for each HX using two plywood 10mm thick sheets as top and bottom and 4 angular aluminum profiles for the 4 sides. Placed the sheets inside the frame and closed it with 8 small screws.
With these three kinds of HXs I made up a small bax out of Polystyrene sheets to do the first benchmark. I made the 4 120mm diameter holes and placed two 12V PC fans (arctic cooling 120 m3/h)
I tried these configurations:
SOLID PP CORE
DISTANCED PP CORE
ALUMINUM CORE
SOLID PP DUAL CORE
ALUMINUM DUAL CORE
The distanced PP core was a total looser, did not even reached a 40% efficiency
Solid PP and aluminum core have equal efficiency, reached 98% with low flow (PC fans with no relevant pressure...)
Dual core rates quite the same, but allows much more air to pass trough.
The last dual core photo was a combination of PP and aluminum cores, same results (but that was quite obvious..)
I will post more precise data as soon as I find them.