Sand in A/C?

[Jaycobro]

I was camping in the smokies this weekend and kept noticed sand or very fine dirt on the floor under the AC (dometic).

My best guess is this is from the AC. It was more than the amount on someone’s shoes, but I can’t figure out where it came from.

If it is the AC is there something I need to do?

[Jaycobro]

Figured it out! It was a dirty AC filter. New to camping this. First time I’ve had to do this!