HEAT INSULATION ECO SASH

PROBLEM TO BE SOLVED: To improve heat insulation loss of a window by a heat insulation device more advantageous than double-layer glass for a building window.SOLUTION: The heat conductivity of glass wool used for a wall is 0.05, the heat conductivity of air is 0.026, and the thickness of 52 mm is required in order to secure the same air layer as the wall 100 mm of the glass wool. When the convection limit of the air layer is defined as 12 mm, four or five layers need to be combined. The air layer is set to a window. Since the glass sash 2 is thinner than the wall, an insufficient portion is added by a wooden window frame 1, a heat insulation eco sash 3 is fitted to the window frame space, the movement of heat is limited and heat is insulated. For the heat insulation eco sash, a film material (polycarbonate sash paper, vinyl chloride resin or a fluororesin film or the like) is stuck with glue or a double-sided tape to both surfaces of a wooden frame material of the thickness of about 12 mm or less formed fully on the window frame and the air layer is held inside. The plurality of film materials are laminated to attain the same heat insulation performance as that of the wall. By installing it inside the window frame, the movement of heat energy is shut off.