| 摘要 |
PURPOSE:To restore a sensing means to its initial performance every time a filter is cleaned by providing a dust sensing means consisting of a light emitting element and a light receiving element facing each other through a dust removing filter and covering the sensing means with a light transmitting dustproof means. CONSTITUTION:Air 8 in a room passes through a dust removing filter means 3, heat exchanges with a heat exchanger means 4, is sucked by a fan of a room air circulating means 2, and then is rectified by a louver 6 to be blown out into the room. Dust is gradually piled up on the dust removing filter means 3, reducing the quantity of signals transmitted from a light emitting element to a light receiving element and piling of dust is sensed by a dust sensing means 10. As the dust sensing means 10 is covered with an outer shell 11 and a light transmitting dustproof means 12 and the dustproof means 12 is integrally constituted of the dust removing filter means 3, the dustproof means can be cleaned together with the filter. |
