What is the function of a condensate drain line in an air conditioning system?

The function of a condensate drain line in an air conditioning system is primarily to remove excess moisture from the air conditioning system. As air conditioning units operate, they cool the air, which causes moisture in the air to condense into water. This water must be efficiently drained away to prevent water buildup, which could lead to water damage, mold growth, or impair the functional efficiency of the system.

By facilitating the removal of this condensate, the drain line ensures that the air conditioning system runs effectively and maintains indoor air quality. This aspect is crucial, as the presence of excessive moisture can lead to a variety of issues, including discomfort and additional strain on the system components. Each of the other functions described in the other options is unrelated to the specific role of the condensate drain line.