I believe it's professionally called foil tape, or sometimes HVAC tape, to distinguish the two. In product listings, you often see seohacks like "HVAC foil seal

I believe it's professionally called foil tape, or sometimes HVAC tape, to distinguish the two. In product listings, you often see seohacks like "HVAC foil sealer duct tape", because consumers still search for duct tape. https://www.lowes.com/pd/3M-2-5-in-W-x-150-ft-L-HVAC-Tape/4009889 https://www.lowes.com/pd/3M-2-5-in-W-x-150-ft-L-HVAC-Tape/40...