Japan is an overlord in household air-conditioner field worldwide thanks to its most advanced technology in the core upstream component--compressor. Many Japanese enterprises, including Daikin, Hitachi, Panasonic, Toshiba, Mitsubishi Heavy Industries and Mitsubishi Electric, are the key players in compressor industry. As such, American enterprises still have competitive strength in high-power air-conditioning compressor industry, represented by Carrier, Trane, Copeland and York. Accordingly, the automotive air-conditioner field is dominated by Japanese enterprises and American counterparts.