Why do data centers prefer centrifugal fans? Main advantages and selection guide
With the rapid development of artificial intelligence, cloud computing, and big data industries, the computing power density of data centers continues to rise, and high-density cabinets, modular computer rooms, and large-scale clusters have become the mainstream of the industry. The servers operate continuously 24/7 throughout the year, generating massive amounts of waste heat. The stability, energy efficiency, and intelligence level of the cooling system directly determine the PUE value, equipment lifespan, and operational safety of the data center. As the core equipment for cooling, fresh air exchange, and air duct circulation in the computer room, the selection of fans is crucial. Compared to axial fans, Centrifugal Fans have become the mainstream choice for modern mid to large data centers, precision air conditioning, and cabinet cooling systems.
Reasons why data centers prefer centrifugal fans
The cooling scenario of data centers has the characteristics of high wind resistance, large load fluctuations, uninterrupted operation throughout the year, strict energy consumption control, and low operation and maintenance requirements. The traditional Axial Flow Fan's low-pressure and high air volume characteristics are difficult to adapt to the complex air duct environment of data centers, while the structural characteristics and performance advantages of centrifugal fans perfectly meet the demanding operational needs of data centers.
1. High static pressure adaptation to complex wind resistance
The air duct system in modern data centers has extremely high resistance, with densely arranged cabinets, dust filters, long-distance ventilation ducts, and cold and hot aisle isolation structures all creating strong ventilation resistance. Axial flow fans have extremely low air pressure and severe air volume attenuation in high resistance environments, which can easily lead to local heat accumulation, short circuits between hot and cold airflows, and uneven heat dissipation, resulting in server high temperature alarms.
Centrifugal fans rely on centrifugal force to do work and can achieve a 90 ° airflow direction. They have the core advantages of high static pressure and a wide range of adjustable wind pressure. They can easily overcome the ventilation resistance caused by filters, pipelines, and dense cabinets, ensuring stable air flow throughout the air duct and accurately delivering cold to the equipment heat source area. They completely solve the heat dissipation problem of high-density computing power clusters and are suitable for all scene heat dissipation needs from ordinary computer rooms to AI high-density computing power rooms.
2. Intelligent stepless speed regulation
The load on data center servers is not constant, with high computing power and heat generation during peak business hours during the day, and reduced load and waste heat at night. Fixed speed fans are prone to energy waste. At the same time, the local temperature difference in the computer room varies greatly, requiring real-time adaptation of heat dissipation equipment to load fluctuations.
At present, the mainstream EC centrifugal fans in data centers are equipped with permanent magnet synchronous motors, which support intelligent stepless speed regulation of 0-10V and MODBUS protocol. They can be directly linked to the dynamic environment monitoring system in the data center, and automatically adjust the speed and air volume according to real-time room temperature, cabinet temperature, and equipment load. Reducing the speed during low load saves energy and reduces consumption, while operating at full load during high load ensures heat dissipation, completely avoiding energy waste caused by constant speed fans, effectively reducing the overall PUE value of the data center, and achieving a comprehensive energy saving rate of over 30%. Compared to the cumbersome solution of traditional AC fans requiring frequency converters for speed regulation, the integrated speed regulation design of EC centrifugal fans has a simpler structure and lower failure rate.
3. Long term stability with low malfunctions
The data center belongs to the first level critical operation and maintenance scenario, and it is strictly prohibited to shut down the cooling system. Even minor fan failures may cause local overheating and equipment downtime, resulting in huge economic losses. Traditional axial flow fans have high turbulence noise and fast bearing loss during high-speed operation, and long-term uninterrupted operation is prone to problems such as air volume attenuation, lagging, and abnormal noise.
The centrifugal fan adopts an optimized aerodynamic structure, with smooth airflow delivery and low turbulence loss. It is designed with a brushless motor, which eliminates the problem of carbon brush wear and greatly extends the equipment life. It can stably meet the requirement of uninterrupted operation for 7 × 24 hours a year. At the same time, its soft start feature can avoid the impact current of multiple wind turbines starting simultaneously, without triggering the upstream protection device to trip, greatly improving the overall stability of the cooling system and adapting to the core requirements of redundant backup and continuous operation in data centers.
4. Low noise, low vibration, easy operation and maintenance
The data center room not only has strict requirements for temperature and humidity, but also has clear standards for operating noise and equipment vibration. Long term high decibel noise can affect the operation of maintenance personnel, and severe vibration may also damage the precision hardware of servers. The aerodynamic design of the backward tilting centrifugal fan is mature, with low airflow friction and slight operating vibration. Compared with axial flow fans of the same power, the noise can be reduced by 5-10 decibels, perfectly adapting to the quiet operation needs of the computer room. At the same time, brushless EC centrifugal fans are basically maintenance free and do not require frequent replacement of parts, greatly reducing the operation and maintenance costs and labor pressure of the computer room.
Selection Guide for Centrifugal Fans in Data Centers
There are many types of centrifugal fans, with significant differences in blade types, motor specifications, and parameter configurations to adapt to different scenarios. Blind selection can lead to problems such as insufficient air flow, heat dissipation failure, insufficient air pressure, air flow attenuation, high energy consumption, and excessive noise. Based on the working conditions of the data center, the selection should follow the four principles of "working condition matching, high efficiency and energy saving, intelligent adaptation, and stable long-term", with a focus on the following core dimensions.
1. Optimal selection of suitable blade types
Centrifugal fan blades are divided into three types: forward, backward, and radial. For data center scenarios, backward leaning airfoil centrifugal fans are preferred. The backward tilting blade fan has moderate air pressure, high aerodynamic efficiency, low energy consumption, and low operating noise. It is the optimal choice for precision air conditioning, air duct circulation, and cabinet heat dissipation in computer rooms, while also meeting the needs of high-pressure air supply and energy-saving noise reduction. Forward blade fans have high wind pressure but high energy consumption and noise, and are only suitable for low-pressure air supply scenarios in narrow spaces; Radial blades have strong durability but high noise levels, making them unsuitable for precision environments in data centers and requiring strict avoidance.
2. Calculate air volume and static pressure
Airflow and static pressure are the core parameters for fan selection, which directly determine the heat dissipation effect. Before selecting, it is necessary to accurately calculate the parameters of the computer room: calculate the total heat dissipation demand based on the number of cabinets, the power of individual cabinets, and the total area of the computer room, and determine the required basic air volume; Simultaneously calculate the total air resistance of the system by combining the length of the air duct, the number of filter screens, and the density of the cabinet, and determine the required static pressure value.
When selecting, a parameter margin of 10% -15% should be reserved to avoid the problem of air volume attenuation and increased air resistance caused by filter dust accumulation after long-term operation, and to avoid insufficient heat dissipation in the later stage. It is strictly prohibited to falsely label parameters or use small horses to pull large vehicles, and there is no need for excessive selection to prevent energy consumption and noise waste caused by excessive air volume. Conventional small and medium-sized computer rooms can use 280-450mm diameter fans, while high-density AI computing rooms and large air duct systems prefer 560-630mm large-diameter high-efficiency fans.
3. Prioritize the use of EC permanent magnet motors
The motor is the core power unit of the fan, directly determining energy consumption and intelligence level. Traditional AC induction motors have low efficiency, inaccurate speed regulation, and high energy consumption, and have gradually been phased out. The selection of data centers must preferably choose EC permanent magnet synchronous brushless motors, which have an efficiency of over 90%, far exceeding traditional motors and significant energy-saving advantages. At the same time, the integrated intelligent speed regulation module can be directly connected to the dynamic environment system of the data center, achieving automation and fine temperature control, and adapting to the intelligent operation and maintenance needs of modern data centers.
4. Pay attention to materials and protection levels
Although the data center room is an indoor clean environment, long-term constant temperature and humidity operation, as well as dust accumulation on the filter and slight humidity in the air, can affect the service life of the fans. When selecting, the fan casing and impeller should be made of corrosion-resistant, high-strength alloy materials that are not easily deformed or corroded, and will not deform or lose balance during long-term high-speed operation. At the same time, the protection level should reach IP54 or above, effectively preventing dust and moisture, avoiding dust from entering the interior of the motor and causing jamming and short circuit faults, ensuring the stable operation of the equipment throughout the year.
5. Matching installation form and redundant design
Select the appropriate installation form based on the equipment structure in the computer room, and prioritize the use of volute free centrifugal fans for precision air conditioning built-in heat dissipation to save installation space; The fresh air circulation in the computer room air duct and the fan wall system use centrifugal fans with volutes to ensure stable air pressure. At the same time, large data centers need to have redundant configurations, with multiple fans running in parallel in critical heat dissipation areas. A single failure does not affect overall heat dissipation, avoiding single point failures that can cause overheating in the data center and improving system fault tolerance.
Under the industry trend of upgrading computing power and reducing energy consumption and costs in data centers, centrifugal fans have become standard equipment in the industry due to their core advantages of high static pressure adaptation to complex air ducts, intelligent speed regulation and precise temperature control, high efficiency and energy saving, stable low noise, and maintenance free. Compared to traditional fans, it can not only solve the problem of heat dissipation in high-density computer rooms, but also continuously optimize the PUE value of the computer room, reducing long-term operating energy consumption costs.
In practical selection, it is necessary to abandon the misconception of blind selection, and combine the computing power density of the computer room, air duct conditions, and operation and maintenance needs. From multiple dimensions such as blade type, air volume and static pressure, motor configuration, protection level, and redundancy design, the optimal fan model should be accurately matched. Choosing the right centrifugal fan can not only ensure the safe and stable operation of the data center throughout the year, but also achieve energy conservation, cost reduction, and efficiency improvement, laying a solid foundation for the high-quality operation of the data center in terms of heat dissipation.