Uninsulated exposed duct - where is it OK
Uninsulated exposed duct - where is it OK
(OP)
Speaking of regular HVAC systems. Rule of thumb is that insulated ducts are OK if exposed in the conditions space.
What is your experience?
The concern is condensation.
I am in northern USA.
I would never use them in restaurants and bars.
I had an issue one in a retail space. It was a building out of an old barn and one of the theories was that the wood had not dried out yet when the HVAC systems were started up.
What is your experience?
The concern is condensation.
I am in northern USA.
I would never use them in restaurants and bars.
I had an issue one in a retail space. It was a building out of an old barn and one of the theories was that the wood had not dried out yet when the HVAC systems were started up.





RE: Uninsulated exposed duct - where is it OK
I personally hate the look of rectangular duct in an exposed space. Restaurant and bars I don't see what the big deal would be. Worst case you internally line the duct.
As far as your barn, I have no idea on what you are talking about regarding the wood drying out. Isn't your ductwork sheet metal? Is there a wood duct out there I'm unaware of? I have heard of duct board.
RE: Uninsulated exposed duct - where is it OK
usual insulation, no matter how good tap-wrapping job done is not nice to be seen outside technical spaces. however, currently some manufacturers offer paints. ordinary insulated ducts painted with the same color as background (ceiling) look very modern and attractive.
one thing is certain - as a hvac engineer you cannot allow uninsulated ducts wherever there is possibility of condensation, no matter what artists ask.
RE: Uninsulated exposed duct - where is it OK
The situation in the barn is that the thought was that there was more moisture in the air from the old barn wood.
RE: Uninsulated exposed duct - where is it OK
RE: Uninsulated exposed duct - where is it OK
RE: Uninsulated exposed duct - where is it OK
The reason for not insulating supply ducts in conditioned spaces is that to dehumidify, the AHU has a discharge temperature of about 55°F during summer, so supply air dew point (depending on coil bypass and ADP) is about 50-53°F. The 55°F supply air might warm on the path to the space, making the duct surface temperature ~58-60°F. So the space dew point would have to be over 58-60°F before condensation occurs on the duct.