What is the main difference between air-cooled and water-cooled condensers?

The primary distinction between air-cooled and water-cooled condensers lies in the medium used for heat exchange. Air-cooled condensers utilize air as the cooling medium. They draw ambient air to cool down the refrigerant inside the condenser coils. As the refrigerant passes through the coils, it releases heat to the surrounding air, allowing it to condense from a gas to a liquid state. This type of condenser is often found in smaller applications or in places where water is scarce or expensive.

In contrast, water-cooled condensers employ water for heat exchange. Water is circulated through a closed loop and absorbs heat from the refrigerant, effectively cooling it down. This setup is more efficient in many industrial applications because water has a higher heat capacity than air, allowing for greater heat transfer. Additionally, water-cooled systems typically perform better in higher ambient temperatures than air-cooled systems.

This fundamental difference in operation and medium highlights why the answer correctly identifies how each type of condenser functions concerning heat transfer.