Question

Which of the following statements explains why you cannot cool down your house by holding the refrigerator open?

Select one:

a. Cold air in the cold box will flow into the kitchen but won’t cause a noticeable temperature change.

b. The refrigerator releases heat into the kitchen to keep the cold box temperature cold.

c. Cold air in the cold box will not flow into the kitchen.

d. The refrigerator removes heat from the kitchen and then replaces it during a cycle.

Answer 1

The answer is option (d)and option (b):The refrigerator removes heat from the kitchen and then replaces it during a cycle.The refrigerator releases heat into the kitchen to keep the cold box temperature cold.

The first and second law of thermodynamics states that energy can never be created nor destroyed and it can only be moved from one location to another or transformed into a different type of energy.

A refrigerator absorbs heat energy from its surroundings under certain conditions and emits or vent the heat out of the refrigerator (usually through the backside of refrigerator),but not out of the building or even the room.Thus keeping the door open simply means that heat removed from the area near the door will simply be pushed back into the room on the other side of the refrigerator.Here the distribution of heat in the room has changed, but the room as a whole will not get cooler.

In fact leaving the door opened for long time increases the heat inside the room as in thermodynamics work is not 100% efficient,so there will be some amount of energy that doesn’t contibute to work. This energy escapes the system as heat.

We cannot say it is never possible to cool a room with refrigerator.It is only possible if the environment is set correctly.For this we have to arrange refrigerator in a way such that heat is vented to outside the room similar to the arrangement of air conditioner.

The options (a) and (c) are wrong .Cold air from refrigerator will flow into the kitchen and changes the temperature near the door into cold by making another part of the room hot by releasing heat .