Dew point is the temperature at which air will be 100% saturated. We would like to emphasize the difference between dew point and pressure dew point. This is important because changing the pressure of a gas changes the dew point temperature of the gas. Although most dew points are stated at atmospheric pressure, pressure dew point should be considered, because condensation can occur in the air pressure lines if the temperature decreases.
A refrigerated dryer cools air down to 5 °C, which gives a pressure dew point of 5 °C.