The present disclosure provides thermally insulating glass laminates that mitigate or prevent heat loss from heated cavities. The present disclosure also provides a heating device, such as an oven, that includes the insulating glass laminates as diffusers, to shield a functional element. In some embodiments, the thermally insulating glass laminates have a first substrate, a second substrate, and a non-uniform low or non-conductive coating layer that forms a chemical bond with at least one inner surface of the substrates. The coating layer can have a thickness of about 0.010 inches or less and forms a pattern that contacts about 30% or less of at least one inner surface of a substrate. The coating layer also forms a plurality of sealed cavities of gas molecules between the substrates. Since there is a small amount of gas molecules in each cavity, convective heat transfer between the substrates is minimized thereby minimizing heat loss through the laminates into the surrounding environment.