Clean the unit / You should also remove any dirt or debris on, around, or in the unit. This will keep unwanted items from clogging its moveable parts, thus preventing the untimely visit of a Denver HVAC professional. To properly clean the unit, SFGate.com gives the following instructions:
Wash the air conditioning unit with a hose to remove bird droppings, dead bugs, dirt and dust. Remove leaves, small branches and grass clippings from the unit. Allow the unit to dry completely.
Keep the unit covered
After cleaning the unit, cover it. This will help protect it from the elements and stray dirt and debris. SFGate.com advises that you use a waterproof cover, perhaps one specially designed for A/C units. However, any plastic or vinyl covering would also do the trick. Afterward, wrap the cover with a vinyl rope or bungee cord to secure it.