Things I'd consider, but have no experience with:
1) replacing the bare duct with the flexible insulated duct stuff
(basically a cylinder of fiberglass with foil inside and out; probably
be easier than insulating the current duct, but that's an option if it
seems feasible given the tight space.
2) investigating radiant heated flooring.


Gntry wrote:
This is lengthy, so be forwarned.
I have an addition on my house(I've only been here 3 yrs) I found out that
the addition was put on in 1983. From what we can tell, it is on some kind
of poured cement walls, like you'd find in a basement, but we don't know how
far down they went or if they are on footers.. They bumped out half of the
back wall(the family room wall and the kitchen wall)they added on a room
apprx. 14' x 24', a vaulted ceiling and a corner fireplace...the problem is,
they left no access to the underneath...this room is freezing...we know that
the only insulation underneath was a single roll of paper backed yellow
batting(insulation) that at one time was stapled to the undersides of the
beams, that has since fallen to the ground, that is only about 12" below(not
enough room to crawl around under there even if we had a way in)we need to
get this room better insulated and some heat to it. There is one heat vent
on the outside wall, and the tube runs underneath the floor, above the
ground, so by the time the air gets to the vent, it's already cold...thats a
span of 14', no wonder its cold.
We were thinking about ripping up the carpet and flooring to expose the
beams and add some kind of a vapor barrier(which we know, there isn't
any)and use furring strips to hold up some insulation close to the floor
along with putting in radiant heat flooring. Any other ideas on how to make
this room livable? or any advice on what we're thinking about doing?