Refrigeration
Energy Efficiency is a relative term when looking at the total cost energy from manufacture to usage to disposal. Total costs have just shifted.
From the consumer to the manufacturer.
The 40's-60's fridges had the least amount of parts to go wrong and easy to recycle (most lasted 30 years). costs to consumer - electricity
Today's may be more electricity efficient on the refrigeration part and the leds not creating much heat. The energy cost to manufacturer all
the extra parts is a lot more than the older units. With all the thermal set plastics are difficult to recycle. They have a program life time of 5 to 12 years before a non major fix. They have more parts that can cause a failure. Costs to the consumer - Manufacture of the unit.
The last 40 years of use more electricity than than 40's -60's ones . Because of the defrost cycle and the door seals heaters, to prevent mildew.
The total energy cost is somewhat a wash . Manufacture~ Consumer ~ Disposal = Total to Environment
The best way to save on usage costs are :
1) Clean the condenser coils at least once a year , more if you have pets
2) No side by side units , The cold will flow out faster with the taller column of air.
3) More doors the better, less volume of air to leak out when open. The old actual ice boxes had lots doors to limit losses.
4) Turn off the door seal heaters when the humidity is lower, if possible .
5) Clearances -- Back 3" - top 3" - sides 1/2 " This creates a draft even when the compressor just shuts off until it cools off.
6) If you need a ice maker -- A door unit - Don't need to open the door == Especially with kids
7) Insulation is the most savings but difficult to implement on a consumer fringe
8)There are more ways to become more efficient on thermal transfer, but more costly to implement
Energy efficiency is nothing new, the Romans used under the floor heating and some of the southern plantation owners had geothermal AC .
They buried wooden pipes in the fields and duct-ed to the house and used a wooden chimney painted black to create a draft.
