Even the water cooled compressors dissipate heat internally from the compressor. So the suggestion that air cooled is as good as water cooled is valid. We also have an Engel running. It's air cooled and introduces no more heat than our water cooled units.
We have 2 water cooled danforth k35? compressors running our fridge and freezer. While they work
well there are some issues:
1) those older mechanical thermostats are junk. Fridge variability is wide and the feedback loop lags. I will replace both with solid state thermostats as the older ones fail.
2) basic coldbox insulation
must be good enough. Don't expect any system to work well if your insulation
is not up to scratch.
3) Same goes for seals
. Poor seals
on your freezer will result in icing up and needing to defrost
4) You want to minimize the duty cycle of your compressors. Less power consumption
, less wear and tear and less heat dissipation in the cabin
5) We find that when left not running one or the other will need a gas topup (usually an ounce) on restart. Tightening the multiple connectors and replacing orings helps. Those damn precharged lines, evaporators and end fitting introduce many leak points.
6) you need to be very pedantic about recharge hygiene. These units have small gas charges and the small orifice designs easily block requiring evaporator replacement.
7) Often the components are assembled with excess loctite? which will eventually break off and block leading to expensive evaporator replacement. I evacuate for many hours when rebuilding.
8) I use high and low pressure gauges to fault find. So add those ports
. The advice to listen to the gurgling stream to confirm correct operation is IMHO bs. I'm half deaf and experienced no change in noise
with an intermittent blockage. Gauges let me isolate and solve the problem in minutes. Again you must purge with gas.
9) If starting from scratch I'd use multiple Engels built in. Much better in all cases than the built in systems.