With a rooftop ventilation system like the Dometic Dust Reduction System, you can significantly reduce the amount of dust in your caravan, breathe fresher air and cut down the cleaning time after caravan trips. Fitted on top of the caravan, this is non-powered system operates whilst driving, When stationary, it also provides free airflow ventilation. The patented design includes the PM10 filter that captures dust particles. It can also reduce harmful airborne particles and pollen that can remain in the air for an extended time after stopping. It has been heavily tested in the dusty regions of Australia and is proven to reduce dust even when driving directly behind a vehicle on a dirt road. The dust reduction system will stop rain from entering the caravan, where the water is directed to outlets but if there is prolonged and heavy rain, water will become trapped in the filter holder where it will then evaporate without entering the caravan.