When a refrigeration system has a dew point condition of -25 degrees, what temperature would you ideally want at the outlet of the evaporator?

In a refrigeration system, the dew point represents the temperature at which moisture begins to condense from the air. When the dew point condition is -25 degrees Celsius, it indicates that the air can hold moisture effectively at that temperature. Ideally, the outlet temperature of the evaporator should be lower than the dew point to ensure that the system is capable of effectively removing moisture from the air, thereby preventing condensation.

Choosing an outlet temperature of -20 degrees Celsius ensures that it is cooler than the dew point and allows for efficient moisture removal while still maintaining adequate system performance. This temperature is sufficiently below the dew point, which helps to ensure that air passing through the evaporator does not reach a point where condensation can occur, promoting effective refrigeration and moisture control.

The other options would either be too close to the dew point or insufficiently low, which might not effectively manage moisture removal. For example, -15 degrees or -10 degrees might lead to condensation issues, while -30 degrees could be excessively low and not necessary for the application, potentially leading to inefficiencies or higher operational costs. Therefore, -20 degrees is the ideal compromise that achieves the intended purpose of the refrigeration system while considering moisture control.