The high-end air-cooled frost-free refrigerator I just bought is the Oma Shanjian S550. As far as I know, this refrigerator uses a high-performance air-cooled inverter compressor with a PWM inverter fan, and uses dual-patented intelligent calculations. The system adjusts the optimal rotation speed for the material and achieves energy efficiency, low noise, and precise refrigeration with frequency conversion technology. It not only runs faster and more smoothly, but also makes the temperature truly constant. At the same time, the Omar S550 uses a multi-dimensional chip sensing system and an intelligent temperature control computing system installed in the refrigerator, so that it can automatically adjust the speed of the compressor and fan according to the temperature inside and outside the refrigerator, and automatically adjust the cooling capacity to make the temperature inside the refrigerator fluctuate. It is smaller, which makes the operation and cooling operation more accurate, forming a "two-dimensional one" intelligent fresh-keeping pattern, which can better maintain freshness at constant temperature and extend the freshness period of food ingredients.