How do energy-efficient windows work?

Energy costs are constantly rising, which hits our budget, especially in winter, when rooms heating requires heavy expenses. It has been proven that a significant part of heat, up to 40%, escapes through the windows. They attempt to solve the issue by producing special energy-efficient structures that retain heat in winter and prevent the cold from escaping from the air conditioner in summer. Let’s find out what these energy-efficient windows are and how they work.