Air Pollution Concerns for East Asian Data Centers
Acid Rain has consequences not only in nature, but in data centers located in proximity to the sources.
An interesting piece in Science News posted earlier this year titled Environmental Policies Matter for Growing Megacities describes the issue of increased air pollution in fast growing cities in East Asia. The Purdue University study notes that regulations and enforcement in the U.S., Europe, Japan and South Korea over the past thirty years have helped to decreased the levels of acid rain forming gases such as sulfate (from SO2) and nitrate (from NOx). In East Asia, this is not the case due either to lack of regulations, lax enforcement, or perhaps both. The result is that acid levels in rainwater, lakes and rivers have risen steadily in East Asia, signifying higher levels of these particles in the atmosphere.
In one example with data collected from 1980 to 2010, “the concentration of nitrate and sulfate in rainwater in the Chinese city of Xi'an is 10 times greater than in New York City.” The authors note that this is extremely significant because this was also a period of growth in GDP, population, and the number of vehicles on the streets of New York as in Xi’an. The conclusion is that laws and regulations coupled with proven technologies work and need to be considered in more locations such as the east Asian megacities.
Air pollution is nothing new, but anyone who has recently visited Beijing or Shanghai knows that the issue is more serious there than in the US and elsewhere. We often see headlines about extreme events and the issue got a lot of attention when the 2008 Summer Olympics were held in Beijing. For a period of months, the Chinese government mandated a period of restrictions on vehicle traffic, closed factories, halted construction projects, watered roadways, and seeded clouds in an effort to reduce the air pollution for the event. Research conducted by the University of Rochester Medical Center examined the data and noted a 60% reduction in sulfur dioxide, a 48% reduction in carbon monoxide, and a 43% reduction in nitrogen dioxide during the games. The study compared air pollution levels to cardiovascular health. The data showed blood pressure, heart rate, and markers of inflammation and blood coagulation – or clotting – before, during, and after the games in 125 healthy male and female medical residents of Peking University First Hospital in central Beijing. The authors found that the markers used in the study essentially mirrored pollution changes; health markers improving as anti-pollution controls were implemented and declining once the air pollution controls were relaxed.
Cancer rate increases and air pollution
Surprisingly, what is good for human health is also good for data center’s health. This is because metal corrodes in acidic environments. And with the advent of lead free electronic regulations such as the EU RoHS Directive, wherein the corrosion protection of non-lead materials used for modern electronics is less corrosive resistant than lead containing materials, the risk is even greater than was found historically. ASHRAE has issued guidelines to describe corrosive gas environments and their potential for data center corrosion in their Technical Committee 9.9 work. The guidelines describe the levels of corrosion potential most modern electronic suppliers refer to in their warranty information, so they are not necessarily just “nice to have”. A link to the ASHRAE guidelines can be found in this Temperature@lert post.
Many data center and server room locations in Europe, Japan, South Korea and the U.S. do not have corrosive gas levels of concern in their ambient environment. However, those downwind of coal fired power plants, pulp and paper mills, or near large airports and truck terminals may want to investigate what their make-up air contains. Many sites in high pollution areas employ specialized filtration, water scrubbers, and other methods on the air intake to reduce corrosive gas contamination levels entering the buildings. All sites, whether or not they are in East Asia, may want to have their ambient air intake evaluated for corrosive gases if they are considering airside economizers for “free cooling”.
Airside Economizer saves energy, ambient corrosive gas levels need to be understood
One piece of good news is that the attack of corrosive gases on electronic circuitry is slowed by low levels of humidity. These gases need water to be corrosive, not liquid water but water vapor also known as humidity and without water molecules corrosion can be slowed. Of course, levels of Relative Humidity (RH) need to be maintained above a certain level to prevent electronic damage due to arcing, so data center facility managers will want to insure the RH levels are above the ASHRAE low limit guidelines. And like temperature sensors, RH sensors are cost-effective to implement and very reliable.
So whether or not your data center is in East Asia or East L.A., monitoring and controlling temperature and RH are important. Those in high air pollution areas will want to pay special attention to both.