
Case 1. The wall that was dry.
A storage room in a private residence in Dubai. The paint was blistering and there was water on the floor. It looked like water in the wall. The wall measured dry. The room air was at 72.1% relative humidity, which put its dew point at 18.7 °C, and the duct ran colder than that: water was condensing on its surface. The water came out of the air, onto the duct, and dripped to the floor. Repainting the wall would have changed nothing.







