Refrigerator cooling power usage I have a refrigerator, that makes a lot of noise, and we have therefore set a time on it will limit the run time to when we are not at the office. But this is where our discussion begins, should we start the refrigerator again at 6pm or 12am, the argument for stating it at 6pm is that we will require to cool less as the items in the refrigerator will not have cooled to the same extend as if we first turn it on at 12am. Now the argument for only turning it on at 12am is that for the power usage is time the only factor, taken from Wikipedia.
What is correct here?
Note: we only have canned soda in the refrigerator, so it will not go bad :D
 A: I take it you're asking whether you should turn on the refrigerator at 6PM (when work ends) or at 12AM (midnight)? From a practical standpoint, unless you have people staying at the office as late as midnight, it seems like it'd be way more convenient to just turn it off when you leave at 6PM.
Also, from a practical standpoint, the food will warm up more if you wait until midnight to start it again, so your food will spoil faster. Another reason to start it at 6PM.
The argument that turning it at midnight will save energy because it reduces the refrigerator operating time (and power consumption only depends on run time) is somewhat flawed because the notion that energy usage depends linearly on time is only valid in steady state operation. 
In reality, provided that the food doesn't warm up too much, the heat transfer rate from the surroundings into the refrigerator is constant throughout the day. Since the energy expenditure of a refrigerator is entirely due to having to pump out this heat, it makes little difference in energy cost.
