inside plenum has condinsation

sully123

installed a 3 ton split system last summer . Turned on the fan to the system the other day smelled an odor coming out of the registers went up to the attic removed a branch off the plenum noticed mold and water on the bottom.I must mention that the plenum  is insulated on the inside opposed to wrapping the outside with blanket insulation. The insulation was soaked what can be causing this, any help would be greatly appreciated

Techman

Moldy

How about humidity from the house migrating to the cold attic and condensing up there?

sully123

inside plenum has condinsation

the bottom of the plenum was saturated and it hasn't been used since last Oct 2010   so I'm wondering could it have been collecting all summer during use , also i don't know if it matters located on long island NY

sully123

inside plenum has condinsation

the bottom of the plenum was saturated and it hasn't been used since last Oct 2010   so I'm wondering could it have been collecting all summer during use , also i don't know if it matters located on long island NY

Paul Fredricks_3

I've seen it

We had one customer where it was so bad the flex duct was full of water in the lower spots. A higher humidity level in the house during the winter, and cold ducts in the attic are the recipe.



With the case of our customer, the house was converted from electric heat. When the house was built they wrapped the whole place in poly. The house was so tight that that it couldn't breath. humidity from the people in the house, sinks, and showers just built up. They probably had a lot of condensation on their windows on cold winter days. The problem was solved by installing a fresh air inlet fan, like an Inforcer.



If you are humidifying in the winter you may be over doing it.