By: Rachel Skillicorn
What makes energy efficient windows the way they are is a few things. While some companies don't pay close attention to the frame work, this type has quality frame materials. They learned that some low-maintenance materials reduce the amount of heat that escapes, which helps insulation. Another thing that is built into them is the two air or gas that fills the inside. This increases the sound insulation and impact resistance. There are also warm edge spacers to help too. The last thing is the special coating on them that reduces heat flow in and out of the window.