Why do data centers control temperature and humidity?

Why do data centers control temperature and humidity?

As we all know, creating an environment with proper temperature and humidity is essential for the good operation of data centers. Only when the temperature and humidity are suitable can the equipment in the data center operate normally and enjoy a longer service life.

I. Impact of High Temperature on equipment operation

(1) relationship between temperature and average time without fault-10 ℃ Principle

The relationship between temperature and the average time of trouble-free operation: due to the increasing density of electronic components used by modern electronic devices, the thermal coupling between components is generated through transmission, radiation and convection. Therefore, thermal stress has become one of the most important factors affecting the timeliness of electronic components. For some circuits, reliability depends almost entirely on the thermal environment. In order to achieve its reliability, the temperature of the component must be reduced to the lowest level actually possible. According to some data, each time the ambient temperature is increased by 10 ℃, the component life is reduced by about 30%-50%, and the impact is also less than 10%. This is the famous "10 ℃" rule.

(2) effect of high temperature on Components

A. semiconductor devices. Electronic components generate a large amount of heat during work. If no effective measures are taken to take three hot spots in a timely manner, the crystallization of semiconductor devices such as integrated circuits and transistors will be formed, this crystallization is an important factor that directly affects computer performance, operating characteristics, and reliability.

According to the experiment, the reliability of each increase of 10 ℃ in the specified range is reduced by about 25%.

When the environment around the device exceeds 60 ℃, it will cause a computer fault. When the temperature during the semiconductor period is too high, the penetration current and current multiples will increase.

B. capacitors. The main effect of temperature on the capacitor is to increase the evaporation of water in the electrolyte of the electrolytic capacitor, reduce its capacity, shorten its service life, change the dielectric loss of the capacitor, and affect the parameter changes such as its power factor. According to the experiment, when the temperature exceeds the specified temperature, the use time of each increase of 10 ℃ is reduced by 50%.

C. Record media. The experiment shows that when the temperature of the tape, disk, and disc is continuously higher than 37.8 ℃, the disk is damaged. When the temperature is continuously higher than 65.6 ℃, the disk is completely damaged. As the temperature increases, the magnetic permeability increases. When the temperature reaches a certain value, the magnetic permeability decreases sharply. The temperature at which the magnetic material loses magnetic properties is called the Curie temperature.

D. insulation material. Due to the influence of high temperature, the printed circuit board made of glass fiber rubber board will be deformed or even softened, and the structure strength will become weak, the copper foil on the Printed Board will also reduce or even peel off the paste strength due to the effect of high temperature. The high temperature will also accelerate the corrosion of the printed plug and socket metal spring card, so that the contact resistance of the contact increases.

E. Relationship between ambient temperature and life of the battery. The battery is the most sensitive device to ambient temperature. the lifetime of a battery is reduced by 50% for every increase of 10 ℃ at a temperature of 25 ℃.

Ii. Impact of Low Temperature on IT equipment operation

Low temperature also causes IT equipment operation, insulation material, battery and other problems. When the data center temperature is too low, some IT devices will not work properly.

(1) equipment cannot run due to low room temperature

When the ambient temperature of the IDC is lower than 5 ℃, the communication equipment cannot run normally. When the ambient temperature of the IDC is lower than-40 ℃, the lead-acid battery cannot provide energy.

(2) Insulation Materials

At low temperatures, the insulation material becomes hard and brittle, so that the structural strength is also weakened. For the bearing and mechanical transmission parts, the viscosity increases due to the cold condensation of its own lubricating oil. When the temperature is too low, high tin content of the welding flux will be terminated, so as to reduce the strength of the electrical connection, and even the release of welding, short circuit and other faults.

(3) Relationship between ambient temperature and discharge capacity of battery

Similarly, when the operating temperature is below 25 ℃, the discharge capacity of the battery decreases as the temperature drops.

Iii. Impact of humidity on the operation of IT devices

Generally, IT equipment requires a humidity of 40%-55%. If the humidity exceeds 65%, the humidity is too high. If the humidity exceeds 80%, the humidity is too low. If the humidity is lower than 40%, the humidity is too low (air drying ).

(1) The impact of high humidity on the operation of IT devices

When the relative humidity of the air is greater than 65%, a water film with a thickness of 0.001-0.01 μM is attached to the surface of the object. When the humidity is 100%, the water film thickness is 10 μm. Such water film may easily lead to "Conductive paths" or flying arcs, which will seriously reduce the circuit reliability.

When the relative humidity remains unchanged, the higher the temperature, the greater the impact on the device, because the water vapor pressure increases with the increase of temperature, water molecules are easy to enter the material.

When the relative humidity increases from 25% to 85%, the thickness of the paper increases by 80%, which is why the printer does not work normally in wet weather.

(2) The impact of low humidity on the operation of IT devices

Electrostatic discharge is a common "hard virus" in the electronic industry. It can occur at specific times when internal and external conditions are met and has become an invisible killer in the electronic industry.

According to reports, only the US electronics industry generates tens of billions of dollars in annual losses due to electrostatic discharge. According to data released by Intel, among the many factors that cause computer failures, electrical overstress (EOS)/ESD is the biggest risk, nearly half of computer failures are caused by EOS/EDS. The damage to computers caused by ESD is concealed, potential, random, and complex.

IT devices are composed of many chips and components that are sensitive to static electricity. Different static sensitive devices have different threshold voltages due to static damage. When the air humidity is too low, staff activities are very prone to electrostatic voltage.

The experiment shows that when the relative humidity of the data center is 30%, the electrostatic voltage is 5000 v; when the relative humidity of the data center is 20%, the electrostatic voltage is 10000 v; when the relative humidity of the data center is 5%, the electrostatic voltage can be up to 20000v or above. This shows the importance of humidity to running IT devices.