This unit has been maintained with regular air filter replacement for the past 2 years. As I do not have *much* knowledge concerning hvac, does this unit look severely water damaged? It looks disgusting to me, and possibly a big air quality issue going on. This is the first time I have opened the unit completely as I am used to just changing the filters. The unit does heat and cool fine, although it takes a while to cool down temps at times. I would like an expert opinion on this unit just by what you see here. I am not as much concerned a lot with the functioning of the unit, because as I said.. it does work, but if running a unit like this can be dangerous?