Modern windows incorporate more technology than ever to further increase their durability, streamline their frame profile, and improve the energy efficiency of the windows glass.
This is where Low-E filmed glass comes into play, letting you bring in the maximum amount of light and the least amount of heat into your home.
Low-e is a film is a protective film applied to either the interior and exterior of a window depending on the climate of the home; for warmer climates like here in Orlando, FL the low-e film would be applied on the exterior of the glass to help repel heat from entering your home and for colder climates the low-e film would be applied on the interior of the window to help keep the heat from escaping your home.
Another benefit to low-e film is the reduction in ultraviolet lights entering your home.
Ultraviolet light is responsible for giving you a tan, or sunburn, when you go to the beach and it acts very similarly to your home, if the glass in your windows does not protect against ultraviolet light then you may see fading on fabrics that sit in direct sunlight or notice heat coming from the light your windows are bringing in.
Low-e film is known for its slightly green hue when compared to raw clear glass.