Black stuff on vents indicates a variety of potential problems, including dirt and dust accumulation, soot, deteriorated insulation, or mold growth, often exacerbated by clogged filters.
You should first try simple solutions like washing the vents out and changing your air filter. If the black particles are sticky or hard to remove, have a musty smell, or you see black spots on the vent, it could be mold, and you should contact us for a thorough duct inspection and cleaning. Additionally, we suggest an indoor air cleaning system to keep the same returning.
www.AlaskanAC.com to schedule a duct cleaning and duct inspection.