Yes. Energy-efficient windows are designed to insulate and prevent and prevent heat transfer between the inside and outside. The glass in our windows are treated with zinc and silver oxides during the cooling process. This application is known a low-emissivity coating (Low-E) and it reflects longer wave radiant energy (heat). So while in the wintertime it bounces the heat back inside your home to keep you warm, in the summertime it does the opposite and bounces the heat from the sun back outside. Another great benefit of the low-E coatings is they also cut down on glare, optimizing your view looking out!