The rise of a new middle class and increased consumer consumption in China have driven upgrades from a split air conditioner (AC) system to a central AC system, which has higher requirements in terms of quality and energy efficiency. Haier’s Hefei air conditioner factory applied advanced algorithms, digital twins, knowledge graphs and other cutting-edge technologies in the research and development (R&D), production and testing of household central AC systems, resulting in a 33% increase in energy efficiency, a 58% drop in the defect rate, a 49% increase in labour productivity and a 22% drop in unit manufacturing costs.