Bob and Christine are sweltering in their hot office. Bob props opens the door of the refrigerator, and says that this will help keep the room cool. Christine says that this won’t work, and in fact the room will gradually get hotter than if the fridge door were shut.

Who is right? Discuss

Christine is right. Although it might seem counterintuitive, propping open the refrigerator door in a hot room will not help keep the room cool; in fact, it will make the room gradually get hotter.

The refrigerator works by removing heat from the inside and releasing it outside through the condenser coils at the back or bottom of the appliance. When the door is closed, the refrigerator maintains a cool and controlled temperature inside by preventing warm air from entering and cool air from escaping.

By propping open the door, the refrigerator is no longer able to effectively regulate its internal temperature. Warm air from the room will continuously flow into the fridge, causing the refrigerator to work harder to remove the heat. As a result, the compressor and other components will generate more heat as they try to compensate for the warm air entering. This increased heat production will eventually lead to a net increase in the overall temperature of the room.

Furthermore, the refrigerator is not designed to cool down an entire room. Its cooling capacity is limited to the confined space inside the appliance. Therefore, the cooling effect provided by the fridge is outweighed by the additional heat generated, resulting in a net increase in the room's temperature over time.

To effectively cool a room, it is recommended to use dedicated cooling systems such as air conditioners or fans, which are specifically designed to circulate and cool down the air in a larger space.

To determine who is right, we need to understand the mechanism of how a refrigerator works and the principles of thermodynamics.

A refrigerator works by removing heat from the inside and expelling it to the outside. It does this through a closed-loop system involving a refrigerant that absorbs heat from the inside of the fridge and releases it to the outside environment.

When Bob props open the door of the refrigerator, the cool air from inside starts to mix with the warmer room air. As a result, the refrigerator is no longer able to maintain the cool temperature inside effectively. The compressor in the fridge has to work harder to remove the heat that is continuously entering the fridge through the open door.

Christine's argument can be supported by the second law of thermodynamics, which states that heat naturally flows from areas of higher temperature to areas of lower temperature. In this case, the room temperature is higher than the temperature inside the refrigerator. Therefore, heat will start to flow from the room into the fridge, making it gradually hotter than if the fridge door were shut.

So, in this scenario, Christine is right. Propping open the door of the refrigerator will not keep the room cool but will, in fact, make the room hotter in the long run.