So far I've read that ducting channels can be made from drywall only. I'm
not interested in enclosing the ducting all the way, it isn't necessary for
where I'm working, so my question is when I install the drywall, is it okay
to butt the drywall up against the ducting or should I leave a gap? I'm
wondering if thermal expansion of the ducting makes it necessary to leave
space or if there are other considerations that make leaving space
necessary.