Don’t fret the dust. There isn’t enough air flow to cause it to inhale much dust. Besides, dust doesn’t like to go up, it’s heavier than air.
Have you ever seen the precleaner on a farm tractor? It’s a simple round housing surrounding the air intake that cause the air to swirl as it’s drawn in, dust being heavier it can’t make into the center, centrifugal force pushes it outwards till it’s against the outer wall where falls harmlessly to the bottom.
Your fridge will do much the same thing.
Years back we drove thousands of km’s of dusty roads to Goose Bay Labrador, dusty as could be, no problem.