In a double-glazed window it is possible to replace External glass with power saving up, so-called K-glass. It nizkoemissionnoe glass with a metal dusting. It interferes with radiation of heat from a premise outside and allows even to manage in a frigid climate more thin single-chamber double-glazed windows. Thus the factor of resistance to a heat transfer of such power saving up double-glazed window without filling with inert gas makes 0,56 (i.e. at external temperature-26S the double-glazed window temperature from outside will make rooms +14,5С), and with inert gas - already 0,67 (internal temperature +16С).
K-glass and gazonapolnenie solves a problem of "crying" windows, and not only. Other interesting property of power saving up glasses - ability to reflect infra-red solar beams, keeping thus a cool in a room during summer heat.