Low-emittance or low-e window film is very durable and will last for years. Its average life expectancy is 10 to 15 years, which will vary depending on climate and whether you use it mainly on the outside of your windows, where it is exposed to the elements. Also, removing the film from the inside to the outside and back as the weather changes can cause it to deteriorate faster.
To get the full life out of your low-e film, slowly peel it away from the window when you need to remove it so the metallic coating is not damaged. Before you reapply, take care to clean the window.