Issue link: http://cp.revolio.com/i/634770
THE DATA CENTER JOURNAL | 13 www.datacenterjournal.com i t's oen been said that the world is becoming a smaller place, and this is certainly true with the increased demand for data mobility and con- nectivity. Our collective need to stay in touch has led to an unprecedented reli- ance on mobile devices. Significantly, these trends are not exclusive to the business world. Twenty years ago, the noise level of shrieking adolescents on the average school bus was deafening. Now, that bus is one of the quietest places anywhere, with every child on board staring intently at the micro-screen in their hands, desperate to keep up with the local version of the Kardashians on Facebook or texting inces- santly with their BFF sitting exactly one bench behind them on the same bus. Fur- thermore, it is not uncommon in today's culture to see that even a toddler's most constant companion is made of plastic and processors rather than skin and bones. RecoRd incReases in daTa TRaffic According to Cisco, data traffic on smartphones, tablets and other mobile devices increased 69% in 2014 compared with the previous year. Nearly half a billion mobile device connections were added in 2014 alone. In addition, hundreds of new mobile apps are created daily. e significant uptick in mobile traffic led Google to change its algorithms earlier this year to give mobile-friendly websites a higher ranking—proof positive that a more mobile world is on the rise. Add to that an ever-rising dependence on streaming entertainment, online retail transactions, GPS applications and digi- tization of historic records in just about any industry, all of which have driven an exponentially rising need for data storage. cLoud-Based enTeRpRises More evidence of a shrinking world lies in the growth of enterprise activities that are cloud based. More and more com- panies are pushing an increasing share of their transactions skyward, leading many to scale back their own IT physical square footage. is shi in data-processing load from enterprise-based facilities to off-site data centers and colos has led to more servers being packed into the latter. Blade servers have been developed in response to the need for more computing power in less space. e downside is that these serv- ers gobble up more power per square foot of real estate than their predecessors, and racks are becoming increasingly denser. As a result, energy consumption and there- fore operating costs are on the rise. In addition, more circuits packed into tighter areas leads to an increased need for cooling capacity and heat dis- sipation. Add to this the fact that mission- critical applications oen demand uptime in the "five nines," oen making redun- dancy a requirement in data center design. Together, a high degree of redundancy coupled with high density translates into greater demand for power. e resulting higher energy costs understandably get the attention of the data center owner/opera- tor, whose goal is to maximize energy ef- ficiencies. Uninterruptible power supplies (UPSs) can also affect a company's energy efficiency. Fortunately, design changes have contributed to improved efficiency. The ups facToR As one of the core components of mission-critical infrastructure in a data center, UPS systems are oen viewed as one of the biggest culprits contributing to energy loss in power distribution. e larger loads commonly found in data centers make it necessary to install larger UPS systems to support them. It's no wonder, then, that interest in utilizing the most efficient UPS system available has increased. In the past, UPS systems were most efficient at peak loads. Since loads in various data centers can swing wildly on the basis of fluctuating customer needs, recent efforts have focused on designing a UPS with a relatively flat efficiency curve, giving data center owners an attractive op- tion for trimming operating costs. ac vs. dc poweR in daTa cenTeRs e ever present challenge to meet the power-hungry needs of a technology- dependent society is a growing burden on the nation's power grid. is situa- tion is getting the attention of organiza- tions with green initiatives, such as the Environmental Protection Agency (EPA) and other like-minded groups. In an effort to emphasize the need to improve data center efficiencies and minimize power consumption, the EPA initiated an Energy Star program in 2010 specifically for data centers. Another area of interest expressed by these organizations concerns the use of high-voltage DC power to energize data centers. Since the bulk of the electrical infrastructure (servers, storage devices, battery backup for UPS systems and other IT-related equipment) require DC power, it stands to reason that this idea has merit. Indeed, several studies have explored the viability of this option. One important consideration is safety, as DC power may expose data center staff to voltages with which they lack experience. Other systems present in a data center, however, such as lighting, security systems and cooling rely on AC power. is situation, coupled with the fact that data centers are now almost exclusively fueled by the existing AC power grid, make high-voltage DC power a longshot at this point. keeping cooL Speaking of cooling, ASHRAE (American Society of Heating, Refriger- ating and Air-Conditioning Engineers) announced its most recent temperature recommendations for maximizing energy efficiencies in data centers in Novem- ber 2014 (see Figure 1). Back in 2011, ASHRAE had developed a classification system for data centers based on need and risk, categorizing them as A1 (most stringent) through A4 (most lenient). According to its Technical Committee (TC) 9.9, which specifically deals with mission-critical facilities, a class-A1 (highest standards) data center can safely tolerate temperatures between 59 and 89.6 degrees Fahrenheit and a relative humidity in the 20% to 80% range. e combination of a higher temperature and a lower relative humidity in the acceptable ranges mentioned above will maximize the energy efficiency of the data center, as