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?