| 摘要 |
The interior of the casing (1) is largely occupied by the fan housing (10). The fan housing consists of a block of sound absorbent material with space for the fan (12) and a passage for air (11) shaped like a snail-shell. The upper part (4) of the casing has air vents with fly screen mesh (19). An internal shutoff flap is operated from outside by a lever (21) on the side of the casing. |
