Just to share something which may or may not work for different environments. The fridge is the only electrical equipment that we run 24hrs a day. We had just installed an off the shelf timer for Euros 2,50 and set them to switch off between 12 midnight and back on at 6 in the morning. The reason being when we are asleep, the fridge remains closed. There is a fair amount of insulation in our fridge as most made for tropical countries are. Therefore temperature can remain relatively low without the need to run the compressor. So instead of running 24hours a day, it does 18. The savings is not really 30% because compressors don't run so often during those periods anyway. But they still do. It was my wife's idea and she's a HAACP auditor
