If you are box framing around the main heating/air trunk, do you insulate inside the box frame? Do you wrap the actually trunk or just install some R-11 inside the framing, before drywalling it?

Thanks

Duct can be insulated inside the duct itself or wrapped around BUT the actual R valve is variable depending upon local codes.

Duct can be insulated inside the duct itself or wrapped around BUT the actual R valve is variable depending upon local codes.

Thanks, it is the main metal trunk that runs the full house length. I am finishing a room and just need to box around a 12' portion for that room. I didn't know if this was just something "extra" I can do to keep the heat/cold on that side of the house or is it actually "required"? Should I wrap the round tube/vents that "branch" off into the new room?

In most cases any insulation you add will be of benefit. Years ago all metal pipe in a home was not insulated since it was deemed not necessary since the pipe was in the envelop of the home itself. You still had to insulate crawl and attic space stuff.