"J Geez" wrote in message
. ..
I am building a 14x30 attached addition to my home. I am almost ready to
pour the slab, and my wife has a new idea and now wants a cathedral
ceiling.
Now I don't have anywhere overhead to run my HVAC duct from my current
house
system to the new room. I need to run a main trunk HVAC duct the long way
(30') underground beneath the slab to the other side of the new room and
then two branches off that the short way (14') that will come up through
the
floor near the walls. They need to come up through the floor or else I
would
have to cut the foundation to get the ducts into the wall. So How is this
typically done with the ducts under a concrete slab? PVC pipe?



I am just going to answer your question.Let you decide what is right.

In a similar situation 2-6" round PVC pipes were run under the slab and
insulated. Two may not be enough for the size of your addition but some
quantity of 6" PVC ducts may be.


--
Colbyt
One picture can be worth a 1000 words.
Post yours at www.ImageGenie.net for FREE.