I replaced half of my windows with Andersen and love them. The other half are picture windows and have frames easily taken apart (secured by a few screws). I need to find a glass maker who have insulated glass the same/equivalent to what Andersen uses. Hopefully, the products meet the energy efficiency standard for tax credit. I learned that Andersen's windows have Cardinal glass. My local glass makers can offer me regular Low-E. But I'm hoping for something equivalent to the SmartSun. Any tip is welcome. Thanks in advance.