The _______________ is the temperature below which the water vapor contained in the flue gas will turn into condensation.

The dew point temperature is the correct term used to describe the temperature at which water vapor in the flue gas will start to condense into liquid water. This concept is crucial in understanding how moisture behaves in various environments, particularly in the context of heating and ventilation systems.

When flue gases are produced during combustion, they often contain water vapor. As these gases cool, they reach the dew point temperature, leading to the formation of condensation. This can be significant because condensation in flues can lead to moisture-related issues, such as corrosion and decreased efficiency in heating systems.

To illustrate, if the temperature of the flue gas remains above the dew point temperature, the water vapor will remain in gaseous form and will not condense, minimizing the risk of moisture-related damage. In contrast, if the temperature drops below this critical threshold, condensation occurs, which can negatively impact the system and the surrounding materials.

The other choices mention concepts related to condensation and temperature but use less precise terminology. For instance, "dew point" is more general and does not specify the temperature aspect. "Condensation point" is not a standard term used in the context of flue gases, and "flue temperature" refers to the temperature of the gases within