US Patent 10294149 Low emissivity coating for windows in cold climates

A low emissivity coating 30 includes a plurality of phase adjustment layers 40, 50, 62; a first metal functional layer 46; and a second metal functional layer 58 located over and spaced from the first metal functional layer 46. A ratio of the geometric thickness of the first metal functional layer divided by the geometric thickness of the second metal functional layer is in the range of 0.6 to 1. The low emissivity coating 30 provides a reference IGU summer/day SHGC of at least 0.4 and a reference IGU winter/night U factor of no greater than 0.4 BTU/hr-ft2-° F. (2.27 W/m2-K).