Answer :

Final answer:

Inside a room air conditioner, a compressor increases the temperature and pressure of a refrigerant gas, which then transfers heat to the room air as it condenses into a liquid. This liquid is cooled as it expands through a valve and moves to the outdoor coils, starting the cycle again.

Explanation:

In the interior section of a room air conditioner, several processes take place to cool the air. An electrically driven compressor, with input work (W), pressurizes a refrigerant gas, elevating its temperature. This hot gas then flows into the condenser coils located within the air conditioner inside the room. Due to the higher temperature of the gas compared to the room's air, heat transfer occurs from the gas to the room. As a result, the gas loses energy and condenses into a liquid. This liquid refrigerant passes through an expansion valve, which reduces its pressure, leading to a decrease in temperature. The now-cooled liquid refrigerant travels to the outdoor evaporator coils, where it absorbs heat from the outside air and evaporates back into a gas, thus completing the cycle. Depending on the weather and the desired effect (cooling or heating), the flow direction of the refrigerant can be reversed, allowing the system to either cool or heat the interior space.