Upon arrival customer said that he was having mold growing in a closet wall but there were no leak stains or wet tiling drywall . Checked in the attic and everything was dry , copper insulation was good and ductwork was in very good shape and didn’t feel any air leaks around them . Customer has had problem with mold before and we changed the ductwork . Customer wants to make sure that the mold is not coming from the ductwork. We need to come back with a heatgun in a warmer day to check if there is any air leaks from the ductwork.