Thermopane windows are a popular type of insulated window that offers energy efficiency and soundproofing benefits. Synonyms for this term include double-paned windows, insulated windows, dual-pane windows, and low-e windows. These terms all refer to windows that have two panes of glass separated by a layer of air or gas, which reduces heat transfer and improves insulation. Double-paned windows are also sometimes called storm windows, although this term can refer to both single- and double-paned windows. Overall, no matter what term is used, thermopane windows are an excellent choice for homeowners who want to save money on energy bills and increase the comfort of their home.