What prevents the cool surfaces of air-conditioning ducts from condensing moisture?

Insulation is crucial for preventing moisture condensation on the cool surfaces of air-conditioning ducts. When air conditioning operates, it cools the air inside the ducts significantly. If the outside temperature of the ducts is lower than the dew point of the surrounding air, moisture can condense on the surfaces. Insulation acts as a thermal barrier, keeping the outer surface of the duct warmer than the dew point of the air.

Without adequate insulation, the cold air inside the duct can lead to rapid cooling of the duct's exterior, creating conditions conducive to condensation. Properly insulated ducts maintain the temperature, reducing the likelihood of moisture buildup, which can lead to problems such as mold growth, reduced efficiency, and potential damage. In summary, insulation is essential to ensure that the temperature of the duct surface remains above the dew point, effectively preventing condensation from occurring.