What is a reasonable condensing temperature for evaporative condensers?

The correct choice is based on the operational principles of evaporative condensers, which utilize the cooling effect of water evaporation to condense refrigerant gases. A reasonable condensing temperature for evaporative condensers is typically derived from the wet bulb temperature of the air passing over the condenser.

When choosing the wet bulb temperature, the added temperature of 10 k (or 10 degrees Kelvin) reflects the nature of how these systems operate. The wet bulb temperature accounts for the cooling effect of evaporation, which is important for heat rejection in the condenser. By adding this increment, it ensures that the temperature of the refrigerant being condensed can be adequately managed, as it allows for a sufficient temperature differential for efficient heat exchange.

In contrast, the other suggestions do not adequately align with the operational factors affecting evaporative condensers, such as the heat capacity of airflow and the specific cooling principles involved. The addition of higher temperatures in other options would typically not align with efficient operation and could lead to compromised system efficiency or increased energy use. Thus, this understanding leads to the conclusion that the choice correlates directly with practical performance limits in refrigeration systems utilizing evaporative condensers.