Deep freeze best located in the cellar
This deep freezer of Bosch is a class A with 237 kWh of annual consumption. This is measured to German Institute for Standardization with -18 degrees inside and 25 degrees of ambient temperature.
Imagine, this chest would be put up in a 15 degrees of warm cellar. Then the difference in temperature would be only 33 instead of 43 degrees. However, this is only one effect that the energy consumption is at a chiller installation place lower. This puts out 23%.
The second effect is the higher efficience number of a heat pump if the condenser (the hot part of a fridge, where all the heat from inside is brought away) is colder. This puts out other 16% saving in the theory. Combines together 36% of savings potential for the installation in the cellar. Why 36? Nevertheless, 18 and 23 is 41! Is right, but 0,767 * 0.84 is just about 0.64.