Exposed Duct Work

[Julia Blythe]

Has anyone done exposed duct work in a SFH or condo? We are debating doing it in an 80 yr old SFH that we are taking down to the studs and giving it a very modern aesthetic. My GC has never done them but said he HAS HEARD that exposed duct work has two problems:

1) Exposed duct work has a tendency to develop condensation on the outside.  I don't understand that because if it were the case, wouldn't the ducts develop condensation inside walls as well, developing mold?

2) The actual duct work used when exposed is much more expensive than the ducts you put in the walls.  My question is, how much more?  Adding extra walls or portions of walls would add to the cost of encasing them.  I'm just wondering net, net, where the cost would be.

Although I truly love our GC, he has a tendency to make excuses when things get out of his comfort zone or with things he has never done before.

Does anyone have any experience or input on exposed duct work?  Below is a picture of how we are considering doing it.

[Account Closed]

@Julia Blythe I posed your question to a friend of mine, who is a Professional Engineer in this field. He designs heating & cooling systems for mostly commercial buildings. He replied:

"Exposed ductwork isn’t uncommon. You see it a lot in old buildings that are remodeled due to the difficulty in adding chases and the desire to leave the structure exposed for aesthetics. The problem with condensation on the ductwork generally occurs when you have a building that has air leakage or you have an entry door that is opening and closing a lot so that moist air is in the room and this moist air condenses on the outside of the cold duct. Also if your system is oversized, the air in the duct may be too cold which would increase the chance of condensation of air on the outside of the duct.

When you run exposed ductwork you generally use round spiral ductwork since it looks nicer. It is more expensive I don’t know exactly how much more expensive it is, but I would think it would be cheaper than boxing in rectangular duct."