Ceiling fans help to circulate the air, keeping the air temperature 3-8 degrees cooler.
吊扇能流通空气，使空气温度降低三到八度。
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A ceiling fan can lower a room's temperature by several degrees. Even something as simple as switching to compact fluorescent light bulbs can make a big difference in electricity bills.
Simply put, the general building materials (such as wood, gypsum board to the metal ceiling) when subjected to high temperature or combustion will spread the fire and heat to other locations.