I have been experiencing a dust problem in the house, including fiberglass particles. I noticed while doing some investigating and sealing for air leaks around the furnace that a small unsealed crack at the juncture of the supply plenum and supply trunk line was actually drawing in smoke from a incense stick. I would have expected this crack to have been blowing out air.
Would it be possible or does anyone know whether this may be common at the duct takeoffs where the collar is attached to trunk line. These are covered with foil faced insulation and taped with silver tape. However I dont think the collar to duct joints may be sealed on all these. Any comments opinions or experience with this appreciated.