Excellent write up.
Let us know when you update it.
Did you add a fan to the condensor coils to improve circulation heat transfer?.
Since the engel is 24v, you could run 2 12v puter fans in series
As the engels are box shaped, you could easily cover them in 1" foam sheet, this would greatly improve their efficiency.
When there running cold, touch the outside of the fridge, and if thats also cold, then that shows you thermal losses due to poor insulation.
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