What Are Server Cooling Technologies?
With the development of high-performance data centers and cloud computing, network servers also face the problem of load and centralization. This undoubtedly brings challenges to server cooling, while also promoting the development and progress of server cooling technology to a certain extent. There are several modern cooling technologies. Let us take a look at the development and application technology of server cooling technology.
Evolution of Server Cooling Technology
From the past to now, server cooling technology has also been developing and evolving, and it has gone through three stages.
Budding period: Probably from 1965 to 2000, the development of mainframe computers and network servers was in its infancy, so traditional air-cooling technology was the mainstay. However, liquid cooling technology had already appeared at that time, mainly by placing electronic components in a non-conductive cooling liquid. The cost of heat dissipation was quite high due to the limited technology of material fabrication.
Mature period: Probably between 2001 and 2009, with the rise of the Internet era, the demand for network servers began to surge, and the cooling requirements became higher and higher. The traditional air-cooling and liquid-cooling technologies could no longer be satisfied with this, so intelligent control technology for fans appeared.
High-speed development period: Since 2010, the development of cloud computing and data centers has made servers need to be placed in a limited space, and heat dissipation has become a top priority. At this time, intelligent control technology and new heat dissipation materials, as the focus of the IT team, brought new vitality to the heat dissipation field.
Why Server Cooling Matters
It is critical to keep the server cool while it is running. Excessive temperatures can cause it to crash and, in severe cases, result in data loss and service interruption. There is a temperature threshold that starts to affect server network performance when the temperature rises above 70 degrees Fahrenheit. At this point, the computer connected to the server will also have some problems affecting the operating system. If the temperature continues to rise to a certain level, it will cause serious problems, such as fire, power outage, etc.
Types of Server Cooling Technologies
In the continuous development and exploration, several types of server cooling technologies have also emerged, including free cooling, liquid cooling, thermal sensor, smart control, and server cabinet cooling.
Air cooling, also called free cooling, its purpose is to guide the direction of the wind, blowing the cold air to the heating element or extracting the hot air from the heating element to achieve server cooling. There are two specific ways.
The first is the fan. Above all, we have to install a large number of cooling devices on the server motherboard, and then install the fans above and below the server cabinet. When the cooling device dissipates the heat of the electronic components, the heat will be taken away by the airflow generated from the fan, thereby realizing cooling.
The second is the cooling airduct. The main method is to place the airduct cover on the electronic components of the server motherboard, the front section is connected with the fan to form the inlet, and the rear end is placed at the rear air outlet of the motherboard to form a convection area. At the same time, the blocking part, the sealing part, and the dividing part form corresponding air ducts. When the heat is located in the air duct, it can be carried away by the airflow in the air duct.
Liquid cooling refers to the method of heat convection or heat conduction, mainly through the immersion or flow of liquid to take away heat to complete server cooling. There are two common liquid cooling methods: immersion and liquid cooling loops.
Immersion: Loading a server with a large number of liquid coolants, such as fluorinated hydrocarbons. The server chips are immersed in liquid coolant. Steam is created when liquid coolant and condenser carry heat away from the chip. The steam will circulate with the coolant to take away heat according to a certain circuit, and after cooling by the heat sink, it will become liquid and merged into the coolant.
Liquid cooling circuit: The heating elements on the server are formed into a single unit, and the heat is dissipated through the water cooling sleeve. Fixed piping, a first heat receiving part, a second heat receiving part, and a large pump are provided in the server case. The cooling liquid can be circulated to each monomer independently, and after passing through each part of the facility, the heat will be transferred to the casing. Finally, it is released into the air by the natural heat dissipation of the casing or the cooling fan to complete the cooling.
A thermal sensor is installed on the server, and the heat is transferred to the outside to achieve the effect of server cooling. The principle of thermal sensor is to transfer heat to low-temperature objects, including heat sinks, cooling plates, and semiconductor plates. The semiconductor uses two conductors to form a circuit. When a direct current passes through, one end is used to release heat, and the other end is used to absorb heat. If the current direction is reversed, the heat absorption and heat release will also be reversed.
Smart control is to use sensors to detect the temperature and load inside the server, and then obtain temperature parameter information through the sensor, adjust the flow of fans or coolant to the control circuit, and realize a smart server cooling mechanism. Its working principle is that when the cooling fan is working, it guides the airflow through the CPU and other server components, and the controller controls the cooling fan to adjust the temperature according to the information sent by the power supply unit and the temperature sensor.
Server Cabinet Cooling
The most straightforward way to cool a server is to leave enough space to ensure good airflow among server racks. Server cooling is accomplished by fans, fan panels installed in the cabinet, or air conditioning. The temperature inside the cabinet can be affected by the door opening, size, and type of components. So you can choose an open or perforated door server cabinet with more space to accommodate a different number of server racks, maintaining a distance of at least 1-2 inches between the equipment and the front and rear of the cabinet to achieve airiness.
To sum up, the problem of service cooling has always been an important thing that deserves close attention. The development of cooling technology is also constantly in line with the needs of data center servers. From the current point of view, various technologies for server cooling are becoming more and more mature. You can design server cooling based on your estimated cost and actual use.