Patent ID: 7964284

Claim:
An insulating glass (IG) window unit comprising: first and second substrates coupled to each so as to form an insulating space therebetween; a layer system supported by at least one of the substrates proximate the insulating space, said layer system comprising an infrared (IR) reflecting layer comprising silver located between at least first and second dielectric layers which comprise silicon nitride, the first layer comprising silicon nitride being closer to the substrate supporting the layer system than is the second layer comprising silicon nitride, wherein said layer system includes only one IR reflecting layer comprising silver; wherein the IG window unit has a visible transmission (T vis ) of 47-60%, a SHGC of no greater than 0.36, and a T vis /SHGC ratio of at least 140; and wherein said layer system comprises the following recited layers with the following thickness ranges: first layer comprising silicon nitride: 150-900 {acute over (Å)} thick first Ni and/or NiCr inclusive layer: 10-80 {acute over (Å)} thick the IR reflecting layer comprising silver: 90-200 {acute over (Å)} thick second Ni and/or NiCr inclusive layer: 10-80 {acute over (Å)} thick second silicon nitride inclusive layer: 400-600 {acute over (Å)} thick; wherein the first layer comprising silicon nitride is located between the substrate supporting the layer system and the first Ni and/or NiCr inclusive layer.