Patent ID: 8132374

Claim:
An external wall panel unit, which is attached to an external wall structure ( 1 ) of a building to form an external wall of the building, the external wall panel unit comprising: an external frame ( 10 ) attached to the external wall structure ( 1 ) and formed in a close curve in such a way that a square tube having a space therein is bent and both ends of the square tube are bonded, the external frame ( 10 ) having a slit ( 12 ) for allowing introduction and evaporation of rainwater, the slit ( 12 ) being formed on an outer face of an upper portion of the bottom thereof; a frame rainwater tube ( 20 ) mounted inside the bottom of the external frame ( 10 ) and inclinedly mounted beneath the slit ( 12 ), the frame rainwater tube ( 20 ) having a hole at an upper portion thereof; a frame duct ( 30 ) being parallel and adjacent to the frame rainwater tube ( 20 ) and inclinedly mounted inside the bottom of the external frame ( 10 ); and a window ( 40 ) mounted on the inner face and at the center of the external frame ( 10 ).