Why is dew temperature important in air conditioning systems?

The temperature at which the water vapor in the atmosphere begins to condense is known as the dew temperature of the air. This property is very important because it is possible to calculate the insulation thicknesses suitable for ducts, cold rooms and domestic refrigerators. That is, if the insulation is bad, there will be a low external surface temperature of the chamber wall or a duct and this way, there will be condensation of the water vapor present in the air on this wall.