The OP is talking about replacing the gas absorption cooling unit in a Dometic refrigerator with a compressor-type cooling unit that runs only on electricity; it uses the same box that's already there. The company that makes it also sells replacement gas absorption cooling units (which also use the same box already there), which are often referred to as "Amish cooling units" as a generic, to distinguish them from cooling units made by Norcold or Dometic.
I'm also interested in the compressor-type cooling unit, but have never found any data on how much electricity it uses in a 24-hour period, to compare it to a residential refrigerator.