Abstract: The capacity of an air conditioner is dynamically balanced with its noise level. An increase in capacity is typically accompanied by higher compressor speed and greater fan power, which in turn leads to increased noise. To address this phenomenon, the concept of energy-to-noise ratio (ENR) has been proposed. The ENR is defined as the effective capacity output per unit of noise, reflecting the “cost-performance ratio” of an air conditioner's comprehensive performance. A new evaluation system based on the ENR has also been proposed to meet the comprehensive evaluation needs for both performance and noise of household air conditioners. Through theoretical analysis of the correlation between air conditioning cooling/heating capacity and operating noise, an ENR mathematical model has been established. Multi-condition experiments have been designed to test several mainstream household air conditioners. The experimental results show that the ENR can effectively distinguish the comprehensive performance levels of different air conditioner products. Products in the high-efficiency zone maintain low noise levels while also having high energy efficiency. Further research has proposed a classification standard based on the ENR, providing a scientific basis for consumer selection and the formulation of industry standards.

Key words: Energy-to-noise ratio, Evaluation system, Grading standard