Mitsubishi, Gree, Midea, Panasonic, Haier. 1. The air-conditioning products sold by Mitsubishi Heavy Industries in China are generally equipped with compressors jointly produced by Mitsubishi Heavy Industries and THACOM in Thailand. Although there are not many bright spots, after all, the technology is mature, the quality is stable and reliable, and a six-year warranty period is provided. The overall performance is good and can reach the national first-class energy efficiency standard. Mitsubishi Heavy Industries called its full DC frequency conversion technology "three-core intelligent control". The three-piece linkage control of compressor motor, internal and external motor and electronic expansion valve ensures the coordination of refrigerant supply and motor speed, and realizes accurate speed and temperature control. In addition, Mitsubishi Heavy Industries has also mastered the PAM+PWM dual-mode frequency conversion technology pioneered by Hitachi, taking into account rapid cooling and heating, and accurately adjusting the temperature by 0.5℃. 2. Gree Gree In recent years, Gree has applied automated manufacturing equipment on a large scale to improve production line management. The internal workmanship of products can almost be in line with the industry benchmark mitsubishi electric. Through disassembly, it is found that even the low-end fixed-frequency products, the copper pipes in Gree machine are welded evenly and carefully, and there are few adverse phenomena such as oxidation, blackening and peeling, which effectively reduces the risk of refrigerant leakage. The dense parts of copper pipes are equipped with noise reduction materials such as damping blocks and damping cotton. The sheet metal part of the shell is strengthened by bending to improve the overall strength. 3. Beauty, beauty, once earned enough attention in the air-conditioning market because of the slogan of "electricity once a night". Although it is questioned because of the lack of test sites and other factors, the energy efficiency of its Himalayan model is as high as 7.36. The main reason for Midea's air-conditioning performance "blowout" is the technical support of Toshiba in Japan. After Toshiba split and merged its air-conditioning business, Midea now has the largest and most complete industrial chain in China's air-conditioning industry, and its core components can be self-sufficient. Midea's three-level energy-efficient fixed-frequency hanging machine is mainly concentrated in smart arc, power-saving star and other series, and the price is generally in the early 2000 yuan. However, the first-class energy-efficient full DC frequency conversion series like I Youth is not expensive, the price is stable at around 3,000 yuan, and the cost performance is excellent.