An RV window can be insulated in the same way as a window in a house. Using rubber weather stripping is an economic solution. Apply the self adhesive rubber strips directly to the window frame. This is cheap and effective but may leave sticky residue when removed. A window insulation kit designed for a permanent structure’s window can be used on an RV window as well. This will involve taping a plastic shrink wrap film to the inside of the window. Then the film is heated with a hair dryer, causing it to shrink and getting rid of any wrinkles or bubbles in the film’s surface. This effective method is inexpensive and simple.