Air Corrosion Monitoring in Data Centers

Identification of Requirement, Understanding of the Problem, Solving the Issues What Are The Symptoms?

IT Companies & Data Centre Companies allocate and invest a sizable portion of their initial budget and their operational budgets in installation and maintenance of technology to ensure maximum performance of the servers, and preventive mechanisms to ensure minimum damage to the functional components of the Data Centres. While preventions against threats posed by fire, power, temperature, humidity and airborne particulates are very well addressed, Data Centers still face multiple problems that are often referred to as “Ghost Signals”.

The symptoms may be:-

• Failures & Outages of Discrete Electronic Components & PCB Boards
• Sporadic Circuit Failure
• Lower Energy Efficiency of Installed IT Equipment
• Inconsistency of Critical Data
• Incorrect and Lost of Data
• Requirement for Replacement of Damaged Electronic Components
• Substantial Increase of Data Center’s Maintenance Costs

Who Are Behind These Problems?

While environmental threats posed by fire, power, temperature, humidity and airborne particulates have long been recognized and successfully addressed in the computer-room environment, the corrosive potential of the air has been largely ignored.

This neglect can have costly ramifications. Over time, even extremely low levels of contaminant gases in the parts per million can cause corrosive damage to electronic equipment. Computer systems and other IT equipment should not be exposed to the threat of corrosive damage. Gas-phase air filtration technology is capable of offering critical protection against airborne contaminants. Along with other environmental control systems and technologies, gas-phase air filtration can help Data Centre Managers with a 360 degree protection against potential environmental threats.

Contaminants, both internal and external are responsible for causing problems related to Corrosion in the critical IT equipment, leading to huge losses in the IT enabled industry. These gases seep into data processing facilities and corrode critical electronic equipment, resulting in malfunction and breakdown of servers, computers, telecom systems, ACs, control panels etc.

Where Does this Air Corrosion Problem Occur?

IT & electronic equipment’s reliability and availability are critical for smooth operation of:

• Data Centers’
• IT Companies & IT enabled services
• BPOs’/KPOs’
• Telecom Companies
• News & Media
• Semi-conductors
• Distributed Control System (DCS)
• Motor Control Centers and Switch Rooms of Petrochemical units, Chemical, Fertilizers, Paper & Pulp, Refinery, Distillery, Brewery, Thermal and Nuclear Plants etc.

How Does Air Corrosion Occur?

Corrosion is defined as the deterioration of a base metal resulting

from a reaction with its environment. In the context of electronic equipment, it refers to the reactions between the Copper and Silver surfaces that are presents in the IT equipment with the immediate surroundings, i.e. the gases present in the atmosphere, and resulting in formation of unwanted compounds. More specifically, when corrosive gases along with water vapour come in contact with a base metal, result in various chemical reaction products. As the chemical reaction continues, pitting and metal loss can occur.

Corrosion on a thin film disk may have serious results. The point of reaction can suffer from loss of ferromagnetism (stored information). Moreover, with accumulation of reaction products on the equipment, mechanical failures (head crashes, wear & tear) can occur on data tracks which were not corroded previously.

Edge connectors on circuit boards can also suffer from corrosion related problems. Irrespective of whether the contacts are solely made of or are gold-plated over a nickel-plated copper substrate, both are susceptible to corrosion. The end result is the same with both copper and composite contacts: a disruption of the contact point. The severity of the environment (i.e., humidity, temperature, types and levels of gases) determines the speed in which corrosion happen, films of corrosion are created and the level of disruption of the flow of electrical current.

Which Are The Corrosive Gases?

All gases do not cause corrosion. The concern is specifically with three types of gases: Acidic Gases, such as hydrogen sulphide, sulphur oxides, chlorine and nitrogen oxides; Caustic Gases, such as ammonia; and Oxidizing Gases, such as ozone. Out of the all the types of gases that can cause corrosion, the acidic gases are typically the most harmful.

These corrosive gases have many sources. Both externally and internally generated gases can pose a problem to sensitive electronic equipment.

In the external environment, corrosive gases are generated primarily from auto emissions, heavy industrial production and heat and power generation. Urban environments are particularly susceptible to such corrosive gases. Of course, weather conditions play a major role in the concentration or dispersal of the externally generated gaseous contaminants. Temperature inversions can trap pollutants, producing a serious air pollution problem.

In addition to general outdoor pollution levels, review of the immediate vicinity of a building is necessary for identification of specific sources of outdoor contamination. Depending upon the location of a building’s supply-air intake, the HVAC system may be drawing in diesel exhaust fumes from diesel generators, loading docks, raising the level of gaseous contaminants in the building.

Offices are more prone to air pollution from gaseous airborne contamination if it is situated near:

• Landfill sites
• Sewerage / Drains
• Swamp / Marshy Lands
• High density traffic
• Process Industry (emanating industrial effluents)

Gaseous contaminants such as Hydrogen Sulphide (H2S), Sulphur Dioxide (SO2) and Oxides of Nitrogen, Chlorine etc., seep into the air conditioned area of modern plush offices.

These gases alone or in combination with humidity and/or with temperature react with the copper and silver parts in the electronic circuit boards, server cards, cooling equipment, datacom connections, leading to electronic corrosion, resulting in malfunction, downtime losses, downtime which translates into data loss, revenue loss, loss of efficiency and ultimately customer dissatisfaction.

Within a building, gases can be internally produced by cigarette smoke and data center printers, fresh paints and varnishes, air fresheners, certain cosmetics, dry cleaning chemicals, aerosol propellants, glues and house cleaning agents. Cleaning compounds, especially industrial strength variants, are known to highly potential sources of ammonia. Cigarette smoke contains both particulate and gaseous contaminants; and is known to be a source of nitrogen oxide. (Even if smoking is not allowed in the computer room, off-gassing can occur from clothing.) Microfiche systems were heavy producers of ammonia, while printers can discharge sulphur compounds and chlorides.

Since most office buildings have their own air conditioning systems and are supposedly controlled environments, it may be assumed that gaseous contaminants created externally or internally, will not enter the computer room. However, the computer room’s dedicated air conditioning system is being used purely for recirculation not pressurization. Without pressurization, gaseous contaminants can seep into the computer room through opening and closing of doors, cracks in wall and ceiling joints, cable and utility penetrations, and spaces above drop ceilings and below raised floors.

Gases are often present in such low concentrations that they are not detectable by the human nose. This does not mean that the gases are not present in sufficient amounts to damage electronic equipment. Generally the odour threshold levels are much higher than the levels needed to cause corrosive damage.

Contaminants are very often generated indoors in Data Processing and Computer Printing Facilities.

Though these facilities are equipped with high quality air filtration equipment to arrest very fine airborne particles generated from high speed printers, and with precision air conditioners to minutely control the temperature and the humidity, these are not capable of removing the existing gaseous contaminants.

Moreover, if because of any reason the fine air borne particles generated by the printers are not removed then they deposit on the surface of disc drives and electronic circuits and can create maintenance downtime.

Why Do We Need To Protect Our Server And Computer Rooms?

The recent interest in Air Side Economization and the spread of Data Centres into varied and diverse

Geographical areas, often in areas with higher atmospheric and air contamination requires greater attention into air quality management in data centres. One major concern of Air Side Economization is the increase in the air contamination leading to corrosion of the metal components of the IT equipment causing outages and malfunctioning of the equipment. The synergistic effects of temperature variation and humidity with the gaseous contaminants has the potentially increases the threat of Air Corrosion, providing greater reasons for close monitoring of the immediate environment of the IT infrastructure of any organization.

While filtering of the outside air while entry into the data centre, for particulate matters and gaseous impurities, is a must; every company dealing with sensitive IT equipment, as a core function of its operations, need to implement a comprehensive checking and monitoring mechanism for Indoor Air Quality inside the data centres and also the corrosion potential of the gases within. These processes should be brought into place with immediate effect and systems need to be implemented to keep a very close watch on the Air Corrosion level inside the data centre, to ensure that the IT equipment are exposed to minimum risk.

What Are The Environmental Standard Formulated?

Standards specifying the type and concentration of airborne contaminants which computers could be exposed to were developed by The Instrument Society of America (ISA). The ISA standard defines or characterizes environments in terms of their overall corrosion potential. A quantitative measure of corrosion potential can be established by using “reactivity monitoring”. Reactivity monitoring involves placing strips of copper metal, called Corrosion Classification Coupons, into an environment for 30 days.

The coupons are then analysed in a qualified laboratory to determine how much corrosion copper film formation in angstroms has occurred. This data is used determination for the corrosion severity level of the environment. The analysed severity level refers to the potential damage that the corrosive gases in the air could cause to electronic equipment. Four levels of corrosion severity have been established by ISAS71.04.

How to Measure the Air Corrosion? Air Contamination in the Data Centers that can lead to Corrosion related failures is one of the most potential risks today. Corrosion Management Strategy has two goals:

• Establish the risk levels for the IT Equipment operated in the contaminated atmosphere,
• Propose strategies to mitigate Corrosion effects.

A model that integrates correlation of the corrosion rate levels with mean time to failure for electronic component and IT Equipment and prognostic tools to estimate the remaining useful lifetime would be considered a successful Corrosion Management Model. Corrosion, being is a synergistic result of gaseous contamination, temperature and humidity variations in Data Centers; it has to be analysed in the context of data centre operating conditions. The development of predictive risk models for Data Centers would be enabled by a full scale deployment of temperature, humidity and corrosion monitoring.

Gaseous contamination can be measured by:

• Measuring the Composition of the Air in the Data Centre,
• Metal Reactivity Monitoring.

For reactivity monitoring, a clean metal surface is exposed to the contaminated atmosphere and the growth rate of the contamination product is measured. Gas composition monitoring can measure risk of Corrosion directly by identification of the Corrosive Gaseous Elements in the atmospheric air.

When should the Monitoring be done?

Based on studies, the following has been identified as the best practices for Indoor Air Quality Analysis and Air Corrosion Monitoring:

• Before selection of site for setting up Data Center,
• After construction of the building structure,
• After Setting up of the Data Center Infrastructure, prior to commissioning
• Post commissioning, once every quarter, since Air quality changes along with season.