What could be causing a ceiling vent to leak without the duct connected, even with no signs of moisture in the attic or on the AC pan?
Asked by Esat Ekşioğlu 
4 weeks ago
Last Updated: October 24, 2024
Do you have any thoughts on why a ceiling vent might be leaking even when the duct isn’t connected? I checked the insulation around the vent in the attic and there’s no sign of moisture at all. The duct is dry, the ceiling is dry, the only wet area is where the water is dripping from and that’s just the Sheetrock. The AC pan is also completely dry and there’s no plumbing in the attic. The duct isn’t connected and the dripping only starts about 15 minutes after I turn on the AC. I’m really puzzled by this.
I’ve had condensation dripping from the duct covers while working at people’s houses. It seems to happen when the A/C is on with windows open or if there’s another source of moisture in the room. Sometimes I suspect it’s due to humid air from the attic or between floors mixing with the cold air from the vent, leading to condensation on the metal cover. Try removing the vent cover next time you use the A/C to check for condensation buildup.
If there’s humidity in your attic, it could be causing condensation on exposed metal surfaces.
Condensation occurs when warm and cool air interact.
When cool air comes into contact with warm air.
I encountered a similar issue following renovations in my bathroom. Just be sure to insulate the duct and boot completely up to where the boot is connected, and seal the edges of the duct with foil tape.