How to Winterize an RV We use both compressed air and antifreeze to ensure the water is removed from the lines and the antifreeze is pure, not mixed with water. Using antifreeze alone is an option, and it will require you to use more to winterize your RV. Avoid relying solely on compressed air, as this can lead to freezing issues in your toilet. Tip - Remember to empty or blow air through your freshwater hose before storing it for the winter. We linked the products we us to winterize RVs in the