| 摘要 |
PROBLEM TO BE SOLVED: To easily and accurately form an opening for air inlet on a ceiling plate. SOLUTION: At the opening edge of a main body frame 12, a protuberance 12c is formed by cutting and erecting so as to locate on each edge, and after fixing the main body frame 12 to a wooden frame 11 with screws, a ceiling plate 13 is attached to the wooden frame 11. By doing so, the tip of each protuberance 12c goes through the ceiling plate 13 and sticks out to the inside of a room 14. Therefore, the location of an air inlet 12b of the main body frame 12 can be seen at an area being surrounded by the four protuberances 12c, and an opening is formed in the area on the ceiling plate 13 by piercing with a knife, etc. |
