Reply To: May one use an escalator on shabbos?

NevilleChaimBerlin: As you see, there are other,more qualified Poskim who are dealing with the issues mentioned. However, the answer to your question is easy: Opening a refrigerator door will allow warm air to enter and make the motor to run longer. Opening your door to a house, will allow cold air to enter and the heating will have to work longer. Hence, the extra energy-especially when it is already working- is not an issue.