Switching from the 120mm, "37 CFM" model to the larger fan (140mm, "47 CFM") has reduced the "excessive" hot air temps around the Heat Exchanger by a great deal. (Remember, anything more than 90F is underirable.) I didn't use the the TM's "OEM" exterior fridge fan in any of these performance tests. Per the previous post, with the smaller fan, temperature inside the Heat Exchanger compartment was reaching 102F (11 degrees above an outside temp of only 91F on that test day). With the larger fan moving more air, I'm getting only 6 degrees above the outdoor value (95F, 6 degrees above today's outdoor temp of 89F).
When running with no fan at all, my thermocouple was reaching 116F - but my upper panel is 50% blocked by the fan, and so I'm not surprised by that bad reading. I didn't try with just the TM's OEM fan, but I know that it is much less effective, and vastly more loud, than my add-on. It's still mandatory for towing, of course.
Next, I moved that 120mm, 37-CFM fan to the inside of the Fridge, taking the place of a "Double-D-Powered mini-fan" I used to use. I have it set horizontal on the upper shelf, blowing directly into the fins on the left side.
After I finished that wiring and cleaned up the bits of trash I'd created, I turned the Norcold to AC power for cool-down, expecting that my traditional "over-night" cool-down would still be appropriate. Before this fan arrangement, the fridge would require 6-7 hours in these afternoon temperatures (88-89) to cool down to 36F. But, with these fans in place, and without packing in any cold food at all, it was completely chilled in just 100 minutes. WOW.
