> since the fridge compressors from the 1940's and 1950's era were very efficient
This statement is very suspect without a citation, because since the 1970s, new refrigerator energy consumption has dropped 3x while volume has doubled [1]. As far as I can tell, fridge efficiency data from before then isn't available, but it's highly unlikely that compressors were more efficient even further back in time.
Some of the improvement in efficiency is undoubtedly much better insulation and seals, but the compressors have definitely become more efficient, which is also why refrigerators are so much more quiet today than they used to be.
This statement is very suspect without a citation, because since the 1970s, new refrigerator energy consumption has dropped 3x while volume has doubled [1]. As far as I can tell, fridge efficiency data from before then isn't available, but it's highly unlikely that compressors were more efficient even further back in time.
Some of the improvement in efficiency is undoubtedly much better insulation and seals, but the compressors have definitely become more efficient, which is also why refrigerators are so much more quiet today than they used to be.
1. https://www.energy.gov/articles/proof-pudding-how-refrigerat...