When installing window film on Low-E (low-emissivity) windows, it's crucial to consider several factors due to Low-E glass's special features designed to improve energy efficiency by reflecting infrared light and retaining heat. Key considerations include:

• Compatibility with Low-E Coatings: Choose a window film compatible with the Low-E coating to maintain its energy-saving benefits. Some films can enhance, while others might undermine, these properties.
• Thermal Stress Risk: Adding film can increase thermal stress, potentially causing glass breakage due to temperature differences across the glass surface. Select a film that manages heat transmission without creating significant thermal imbalances.
• Warranty Considerations: Ensure installing window film doesn't void the window's manufacturer warranty. Check warranty terms and consult with both window and film manufacturers.
• Visual Aesthetics and Light Transmission: The addition of window film can alter window appearance and the amount of natural light entering. The impact on building aesthetics and interior lighting should be considered.
• Energy Efficiency Goals: Aim for a window film that complements the Low-E glass's energy efficiency, enhancing without compromising its functionality.

Consulting a professional installer experienced in both Low-E glass and window film is recommended to navigate these complexities, ensuring the film supports the window's performance and the building's energy efficiency and comfort effectively.