If the door of a running refrigerator in a closed room is kept open, what will be the net effect on the room?
- It will make the temperature go up and down
- It will make no difference on the average
- It will heat the room
- It will cool the room
A fridge can be though of as a heat pump. It takes air inside the fridge and cools it by removing heat from it. This heat has to go somewhere, though, and is usually blown out the back of the fridge by a little fan.
For this reason, when a fridge is running it is really warming up the room a little bit. In fact, since we can’t design a fridge to be perfectly efficient (the 2nd law of thermodynamics guarantees this), some of the electrical energy gets converted to heat, so more heat gets dumped outside the fridge than gets pumped out, so even if you open the fridge door to let the cool air escape the fridge will still be heating the room more than cooling it.
The correct option is C.