美国:美国是世界第一经济大国,人民生活水准较高,对居住的舒适性要求也较高,这些都促进了该国家用小型中央空调的普及使用。美国的别墅型住宅(Single House)具有宽敞、高大的特点,通常由中、高收入的家庭居住。由于其层高较大,具有足够的建筑空间用于布置风道,因此在美国,风管式系统在家用小型中央空调中所占的比重相当大。同时,由于美 United States: The United States is the world's number one economic powerhouse with a higher standard of living and higher comfort requirements for living, all of which have contributed to the popularization of the use of small central air conditioners in the country. The Single House in the United States is spacious and tall, often home to middle and high income families. Due to its large floor height and sufficient building space for air ducts, air duct systems account for a significant proportion of residential small central air conditioners in the United States. At the same time, due to the United States