no, i use mainly for sound dampening. since its used between basement ceiling and 1st floor, no need for thermal insulation. wasn't sure if it wrap around the interior HVAC duct is hazard or not.Insulation is insulation regardless of your purpose for it - is this going to put the duct outside the conditioned air envelope of the house? If not, it would be fine.
Interior ??? you mean wrapping it around the exterior of the duct, right ?.. wrap around the interior HVAC duct...
nah interior HVAC duct in the basement i ONLY do it due to sound dampening NOT thermal isolation. doing a home theater so need separate sound from basement to first floor. but there are duct to the vent on first floor.Interior ??? you mean wrapping it around the exterior of the duct, right ?
If your plan is to wrap a 6" duct, and the duct is between joists, you might be having a fair amount of fun doing that.
Might need some kerf cuts to get it around 3 sides of the duct, but all the way around will be a real challenge.
Rockwool is pretty stiff, and doesn't like to make tight bends. If you buy the acoustic rockwool, its even more stiff. (Difference between acoustic and thermal rockwool is just that the acoustic version is 25% denser).