update on itWe had Joe come out and clean our vents and we figured everything was fine and some of the black stuff was normal at first but a few months later we keep seeing it come out of the vents. I really don't think they did a great job cleaning anything just stirring stuff loose. We called them and their response was we will see when we can look at it and call you. Received a call back and explained what was happening and they were coming out the next day.