Question

Consider two identical rooms, one with a refrigerator in it and the other without one. If all the doors and windows are closed, will the room that contains the refrigerator be cooler or warmer than the other room? Why?

Short answer

Answer: The room containing the refrigerator will be warmer than the room without one due to the heat released by the refrigerator during its operation.

Step-by-step solution

Understand the working principle of a refrigerator

A refrigerator works on the principle of heat exchange. It removes heat from the items placed inside and releases this heat into the external environment. To be more specific, a refrigerator consists of a compressor, a condenser, an expansion valve, and an evaporator. The compressor compresses the refrigerant, turning it into a high-pressure, hot gas. The hot gas then flows through the condenser coils, where it loses heat energy to the room and becomes a high-pressure liquid. The liquid then flows through the expansion valve and enters the evaporator coils, where the pressure and temperature drop. This allows the refrigerant to absorb heat from the items in the refrigerator, turning it back into a low-pressure gas. The process then starts over when the gas travels back to the compressor.

Determine how the working principle of a refrigerator affects room temperature

While the refrigerator effectively absorbs heat from the items inside, it also releases the heat into the room where it is placed. The heat released is slightly greater than the heat absorbed, mainly due to the energy needed to run the compressor and due to the inefficiencies in the heat exchange process. This means that there would be a net increase in the room's temperature over time when the refrigerator is running.

Compare the temperatures of both rooms

If all the doors and windows are closed in both rooms, the room without a refrigerator will have no active source of heat generation or removal. In contrast, the room with the refrigerator will have heat added due to the working mechanism of the refrigerator. Therefore, the room containing the refrigerator will have a net increase in temperature compared to the room without a refrigerator.

Conclusion

When comparing two identical rooms, one with a refrigerator and the other without one, the room containing the refrigerator will be warmer than the room without one due to the heat released by the refrigerator during its operation.