| 摘要 |
In a double sash structure comprising a first sash facing to the outside and a second sash facing to the inside, a window frame of the first sash is formed of a metallic material and a window frame of the second sash, which is formed of a non-metallic material having a low heat conductivity, is disposed contiguously to the window frame of the first sash. By virtue of the low heat conductivity of the window frame of the second sash, lowering of the temperature in the room and formation of dew by condensation of moisture can be prevented. Accordingly, a double sash structure excellent in the heat-insulating property and having a beautiful appearance and an improved strength, which can be readily assembled, can be provided. |
