Although power supplies do not have temperature sensors like CPUs and graphics cards, it is still easy to measure the temperature of the power supply from the position of the power supply air vent at the back of the chassis. Modern multimeters generally come with temperature probes. Wrap the temperature probe of the multimeter with insulating material such as plastic, insert it into the power supply from the position of the power supply at the back of the chassis, and with time and patience, you can measure the temperature at multiple locations within the power supply. Using an infrared thermometer allows for quick and comprehensive measurement of the temperature at various locations within the power supply. Simply aim the infrared thermometer at different parts inside the power supply from the back of the chassis, and you can easily and quickly read the temperature at different locations within the power supply. Tests have shown that the temperature of fanless power supplies for computers with centralized air supply and fresh air cooling is much lower than that of fan-equipped power supplies of the same power, by about 5 to 10 degrees, which is generally consistent with the above analysis. This indicates that in computers with centralized air supply and fresh air cooling, the cost of fanless power supplies is roughly equivalent to that of traditional fan-equipped power supplies. When computer cooling enters the era of people-oriented design, excessively high fan speeds lose their practical value due to noticeable noise, and are basically only seen in media reviews; when computer cooling enters the multi-core era, excessively low fan speeds are subject to various limitations due to increased requirements for the size of the radiator, and are rarely seen in practice. It can be seen that a moderate fan speed is a basic requirement for all silent computers. On this basis, pursuing ultimate silence in computers also requires further reducing the number of fans.

The key to achieving silent breakthroughs in computers with centralized air supply and fresh air cooling lies in the implementation of centralized air supply and fresh air cooling for computer cooling, which is similar to the central air conditioning in buildings. There is no need to install fans on the power supply, CPU, and graphics card for separate air supply, as is the case with traditional computers. Computers with centralized air supply and fresh air cooling emphasize achieving a balance between silence and cooling with an appropriate number of fans and moderate speeds. The minimum number of fans required is one; for a 120mm fan, the moderate speed is around 1300rpm, and for an 180mm fan, it is around 900rpm. At moderate speeds, fans with larger diameters have better cooling effects than those with smaller diameters, and multiple fans have better cooling effects than a single fan. Those who pursue ultimate silence can use one fan; those who pursue ultimate cooling can use large-diameter fans or multiple fans. In other words, the overall cooling effect of pressure difference not only achieves both silence and cooling, but also provides a considerable degree of flexibility between silence and cooling.

The heat dissipation and heat removal capabilities of the centralized air supply and fresh air cooling system can be calculated as follows.

Taking the commonly seen 120mm fan in computers as an example, its air volume is approximately 50 CFM (Cubic Feet per Minute, 1 CFM = 4.72 × 10-4 m3/s) at a rotational speed of 1300 rpm. Assuming the temperature of the airflow entering the chassis is 28℃ and the temperature when it exits the chassis is 38℃, with a temperature difference of 10℃ (or K), the heat discharged outside the chassis by the 120mm fan per unit time is calculated as follows: (specific heat of air: 1.005 J/g·K, specific gravity of air: 1290 g/m3)

　　＝1.005×（50×4.72×10-4×1290）×10

=305.96 watts

Currently, the heat generation of most computers is below 300 watts, especially for computers with general configurations, whose total power is only around 200 watts, far from reaching 300 watts in heat generation.

The above formula describes the centralized air supply and fresh air cooling system from a system perspective. Airflow is equivalent to input, the heat carried away by airflow is equivalent to output, and specific heat is equivalent to the system function. Of course, when designing the power supply, CPU fanless cooling device, and graphics card fanless cooling device in the centralized air supply and fresh air cooling system, thermal design theory is also required. In thermal design theory, the cooling capacity of a fan-equipped radiator is proportional to its cooling area, proportional to airflow rate, and proportional to the temperature difference between the radiator surface and the airflow. Based on this, the planning of radiator size and the distribution of airflow rate can be carried out.