Server room air conditioner

The computer room precision air conditioner is a special air conditioner designed for the computer room of modern electronic equipment. Its working accuracy and reliability are much higher than ordinary air conditioners. We all know that computer equipment and program-controlled switch products are placed in the computer room.

It consists of a large number of dense electronic components. To improve the stability and reliability of these devices, it is necessary to strictly control the temperature and humidity of the environment within a specific range. The computer room precision air conditioner can control the temperature and relative humidity of the computer room within plus or minus 1 degree Celsius, thus greatly improving the life and reliability of the equipment.

Effect:

Information processing is an indispensable link in many important jobs. Therefore, the normal operation of the company is inseparable from the data room with constant temperature and humidity. IT hardware generates unusually concentrated heat loads while being very sensitive to changes in temperature or humidity. Fluctuations in temperature or humidity can cause problems, such as garbled characters in processing, or even a complete system shutdown in severe cases. This can cost a company a huge amount, depending on how long the system is down and the value of the data and time lost. Standard comfort air conditioners are not designed to handle the heat load concentration and composition of the data room, nor to provide the precise temperature and humidity set points required for these applications. The precision air-conditioning system is designed for precise temperature and humidity control. The precision air-conditioning system has high reliability and ensures the continuous operation of the system all year round, and has maintainability, assembly flexibility and redundancy, which can ensure the normal air conditioning of the data room in four seasons. run.

Computer room temperature and humidity design conditions

Maintaining temperature and humidity design conditions is critical to the smooth operation of a data room. Design conditions should be 22°C to 24°C (72°F to 75°F) and 35% to 50% relative humidity (R.H.). Just as bad environmental conditions can cause damage, rapid temperature fluctuations can negatively affect hardware operation, which is one reason to keep hardware running even when it’s not processing data. In contrast, comfort air conditioning systems are designed only to maintain indoor temperature and humidity levels of 27°C (80°F) and 50% R.H., respectively, in summer with an air temperature of 35°C (95°F) and outside conditions of 48% R.H. Relatively speaking, comfort air conditioners do not have dedicated humidification and control systems, and simple controllers cannot maintain the set point required for temperature

(23±2℃), therefore, there may be high temperature and high humidity resulting in a wide range of fluctuations in ambient temperature and humidity.

Problems caused by the unsuitable environment of the computer room

If the environment of the data room is not suitable, it will have a negative impact on the data processing and storage work, and may cause data operation errors, downtime, and even system failures frequently and completely shut down.

1. High and low temperature

High or low temperatures or rapid temperature fluctuations can disrupt data processing and shut down the entire system. Temperature fluctuations can alter the electrical and physical properties of electronic chips and other board components, resulting in operational errors or failures. These problems may be temporary or they may persist for several days. Even temporary problems can be difficult to diagnose and fix.

2. High humidity

High humidity may cause physical deformation of tapes, scratches on disks, condensation on racks, adhesion of paper, breakdown of MOS circuits and other failures.

3. Low humidity

Low humidity not only generates static electricity, but also increases the discharge of static electricity, which will lead to unstable system operation and even data errors.

The difference between the special air conditioner for the computer room and the ordinary comfortable air conditioner

The computer room has strict requirements on temperature, humidity and cleanliness. Therefore, the design of the special air conditioner for the computer room is very different from the traditional comfort air conditioner, which is reflected in the following five aspects:

1. The traditional comfort air conditioner is mainly designed for personnel, the air supply volume is small, the air supply enthalpy difference is large, and the cooling and dehumidification are carried out at the same time; while the sensible heat in the computer room accounts for more than 90% of the total heat, which includes the equipment itself heats up, lighting generates heat. Heat, heat conduction through walls, ceilings, windows, floors, as well as solar radiation heat, infiltration wind through gaps and fresh air heat, etc. The amount of humidity generated by these heat generation is very small, so the use of comfort air conditioners will inevitably cause the relative humidity in the equipment room to be too low, which will accumulate static electricity on the surface of the internal circuit components of the equipment, resulting in discharge, which damages the equipment and interferes with data transmission and storage. At the same time, since the cooling capacity (40% to 60%) is consumed in dehumidification, the cooling capacity of the actual cooling equipment is greatly reduced, which greatly increases the energy consumption.

The special air conditioner for the computer room is designed to strictly control the evaporation pressure in the evaporator, and increase the air supply to make the surface temperature of the evaporator higher than the air dew point temperature without dehumidification. Moisture loss (large air supply, reduced air supply enthalpy difference).

2. Comfortable air volume and low wind speed can only circulate air locally in the air supply direction, and cannot form an overall air circulation in the computer room. The cooling of the computer room is uneven, resulting in regional temperature differences in the computer room. The temperature in the air supply direction is low, and the temperature in other areas is low. If the heat generating equipment is placed in different positions, local heat accumulation will occur, resulting in overheating and damage to the equipment.

The special air conditioner for the computer room has a large air supply volume and a high number of air changes in the computer room (usually 30 to 60 times/hour), and an overall air circulation can be formed in the entire computer room, so that all equipment in the computer room can be cooled evenly.

3. In traditional comfort air conditioners, due to the small air supply volume and the small number of air changes, the air in the equipment room cannot guarantee a high enough flow rate to bring the dust back to the filter, and deposits are formed inside the equipment room, which has a negative impact on the equipment itself. . Moreover, the filtering performance of general comfort air-conditioning units is poor and cannot meet the purification requirements of computers.

The special air conditioner for the computer room has a large air supply and good air circulation. At the same time, because of the special air filter, it can filter out the dust in the air in a timely and efficient manner and maintain the cleanliness of the computer room.

4. Because most of the electronic equipment in the computer room is in continuous operation and has a long working time, the special air conditioner for the computer room is required to be designed to operate continuously with a large load all the year round, and to maintain a high reliability. Comfort air conditioning is difficult to meet the requirements, especially in winter, the computer room has many heating devices due to its good sealing performance, and the air conditioning unit still needs to work normally. At this time, the general comfort air conditioning is difficult because the outdoor condensation pressure is too low. In normal operation, the special air conditioner for the computer room can still ensure the normal operation of the refrigeration cycle through the controllable outdoor condenser.

5. The special air conditioner for the computer room is generally also equipped with a special humidification system, a high-efficiency dehumidification system and an electric heating compensation system. Through the microprocessor, the temperature and humidity in the computer room can be accurately controlled according to the data returned by each sensor, while the comfort air conditioner Generally, it is not equipped with a humidification system, which can only control the temperature with low precision, and the humidity is difficult to control, which cannot meet the needs of the equipment in the computer room.

To sum up, there are significant differences in product design between dedicated air conditioners for computer rooms and comfort air conditioners. The two are designed for different purposes and cannot be used interchangeably. Computer room special air conditioners must be used in the computer room. Many domestic industries, such as finance, post and telecommunications, television stations, oil exploration, printing, scientific research, electric power, etc., have been widely used, which improves the reliability and economical operation of computers, networks, and communication systems in the computer room.

Application range:

Computer room precision air conditioners are widely used in high-precision environments such as computer rooms, program-controlled switch rooms, satellite mobile communication stations, large medical equipment rooms, laboratories, test rooms, and precision electronic instrument production workshops. The cleanliness, airflow distribution and other indicators have high requirements, which must be guaranteed by the dedicated computer room precision air-conditioning equipment that operates 24 hours a day, 365 days a year.

Features:

Sensible heat

The host and peripherals, servers, switches, optical transceivers and other computer equipment installed in the computer room, as well as power support equipment, such as UPS power supply, will dissipate heat into the computer room by means of heat transfer, convection, and radiation. These heat only cause the temperature in the computer room. The increase is sensible heat. The heat dissipation of a server cabinet ranges from a few kilowatts to a dozen kilowatts per hour. If a blade server is installed, the heat dissipation will be higher. The heat dissipation of large and medium-sized computer room equipment is about 400W/m2, and the data center with higher installed density may reach more than 600W/m2. The sensible heat ratio in the computer room can be as high as 95%.

Low latent heat

It does not change the temperature in the computer room, but only changes the moisture content of the air in the computer room. This part of the heat is called latent heat. There is no humidity dissipation device in the computer room, and the latent heat mainly comes from the staff and the outdoor air, while the large and medium-sized computer room generally adopts the management mode of man-machine separation. Therefore, the latent heat in the engine room is small.

Large air volume and small enthalpy difference

The heat of the equipment is transferred to the equipment room by conduction and radiation, and the heat is concentrated in the areas where the equipment is dense. The air volume takes the excess heat away. In addition, the latent heat in the machine room is less, and dehumidification is generally not required, and the air does not need to drop below the zero temperature when passing through the evaporator of the air conditioner, so the temperature difference and enthalpy difference of the supply air are required to be small. Larger air volume.

Uninterrupted operation, year-round cooling

The heat dissipation of the equipment in the computer room is a steady heat source and operates uninterrupted throughout the year. This requires a set of uninterrupted air conditioning guarantee system, and there are also high requirements on the power supply of the air conditioning equipment. And for the air-conditioning system that protects important computer equipment, there should also be a generator set as a backup power supply. The long-term steady-state heat source causes the need for cooling even in winter, especially in the southern region. In the northern region, if cooling is still required in winter, the condensing pressure of the unit and other related issues need to be considered when selecting an air-conditioning unit. In addition, the proportion of outdoor cold air intake can be increased to achieve the purpose of energy saving.

There are many ways to send and return air

The air supply method of the air-conditioned room depends on the source and distribution characteristics of the heat in the room. According to the dense arrangement of equipment in the equipment room, more cables and bridges, and the wiring method, the air supply method of the air conditioner is divided into lower and upper return. Top feed back, top feed side back, side feed side back.

Static pressure box air supply

The air conditioner in the computer room usually does not use pipes, but uses the space at the lower part of the raised floor or the upper part of the ceiling as the return air of the static pressure box. static pressure is equal.

High cleanliness requirements

Electronic computer rooms have strict air cleanliness requirements. Dust and corrosive gases in the air will seriously damage the life of electronic components, causing poor contact and short circuits. In addition, it is necessary to supply fresh air to the equipment room to maintain positive pressure in the equipment room. According to the “Design Specifications for Electronic Computer Room”, the dust concentration in the air in the main engine room is tested under static conditions. The number of dust particles greater than or equal to 0.5m per liter of air should be less than 18,000. The pressure difference between the main engine room and other rooms and corridors should not be less than 4.9Pa, and the static pressure difference with the outdoor should not be less than 9.8Pa.