Got a problem that recently cropped up. Just noticed some ceiling water damage. Went into the attic to check it out and found that the water source is from ym A/C duct.
The offending duct shows water damage from the air handler down one main line to the kitchen - about 30 feet. The duct lines are metal. I cut the insulation open to check for direct leaks. None found. Also, since the issue runs the length of 30 feet, it would seem odd for there to be a leak unless there was a seam in the ducting where the leak is. Not such seam.
I'm really at a loss here. Before I call the A/C guys, I'm looking for a little input. Also, why just this part of the A/C duct and not in other parts of the house. Why all of a sudden and not for the prior five years? I know, I know; tough to say without actually running some tests and performing some examinations.
So, is a leak likely even if there is condensation running a 30 foot length of ducting? How about the venting of hot air from the attic? Could that be an issue? Should I just replace the offending length with flexible ducting instead of trying to troubleshoot? Seems it might be a quicker alternative.
One last thing. We even in areas where there is batt insulation adding additional insulation to the duct, there is condensation.