This is a common problem when a system is getting older, or has had ground moisture problems over the years. Eventually the metal will rust and break down, allowing entry points for dirt to enter. This is especially true on the floor vent boxes. Duct Coating will remedy all of these problems and halt the dirt from blowing out every time you turn the system on. Duct sealing will also make the system work more efficiently.
I HAVE DIRT BLOWING OUT OF MY AIRDUCTS
