I want to install double glazed replacement windows that have high solar heat gain and a low u value. The Cardinal product for this purpose is LoE 180 applied to surface #3. I would like to have the 180 coating applied to both surface #3 and #2 to further decrease the U value but maintain the high solar heat gain attributes of the IGU. My local Marvin window distributor told me that Marvin told him that 180 could not be used on adjacent surfaces as I am requesting. I have not spoken directly to Cardinal about this. Unless LoE 180 has anisotropic properties that are determined by the coating - glass interface I do not see any reason why it cannot be applied to both surface #3 and #2. I know that Cardinal sells double glazed IGU's with various coatings -270, 366- on surface #2 and i81 on surface #4 to decrease the U value of the IGU but these options all have high solar heat gain ratings. Can anyone enlighten me on the feasibility of applying high SHGC LoE 180 coating to both surface #3 and #2?