Traditional European sliding windows open left and right, while sliding windows open vertically up and down. Normally, whether it is a sliding window or a sliding window, the opening area will not exceed 1/2, but after changing from sliding left and right to lifting up and down, not only is the opening method more scientific and reasonable, but the human comfort is also greatly improved. Because, in my country's building openings, the height from the ground is generally 900-1000mm. If the height of the sliding window is designed to be 1600-1800mm, the opening height of 1/2 is 800-900mm, which is close to the height of the human body, and the ventilation and comfort are greatly enhanced.