I’m late to this thread.
I would recommend 40 degrees F or lower for a cooler. Going warmer I do see mold and less ‘life’ of stored product. If you want look at u of WI HACCP Therm 2.0 and do some growth comparisons.
Also, the wall mount a/c units do promote blowing all kinds of microbes into meat. Look at their filter system, where it sucks air from and then where it blows it to. Compare to a commercial refer unit in a meat plant. Also look at unit cleaning.
just my $0.02.