Consider these five unexpected ways to improve data center efficiency.

AIR FILTRATION

High-performing, electret-enhanced air filters provide improved filtration and can be changed less often than conventional commercial filters.

What is an easy way to improve data center energy efficiency and lower maintenance costs simultaneously? Upgrade the air filter.

When outside air is pulled in by data centers, known as free air cooling, it must be filtered thoroughly to ensure that equipment continues to function properly and efficiently. Dust alone can pose a severe threat to the data center and lead to mechanical problems, component corrosion and electrical impacts, such as short circuiting and impedance changes.¹While air filtration systems in data centers are designed to remove the majority of dust particles from the air, operators face challenges with effectiveness and energy use required.

A dual-filter air filtration system is commonly used in large commercial buildings. However, this approach is not optimal to support a data center’s heat generation and cooling needs, which require much higher levels of filtration, airflow, and energy efficiency than the average commercial building. Thus, more filters are needed for efficient and effective filtration.

Conventional filters require frequent changing — typically two to four times per year for the pre-filter and once a year for the final filter. Furthermore, they do not offer the best performance in terms of pressure drop. Air movement systems must work harder and consume even more power to achieve proper filtration.

A trend is emerging to overcome these air filter obstacles and enable more frequent use of the efficiencies offered by free air cooling. New filters incorporate electrostatic technology into filtration material — electret — which works in conjunction with the mechanical filtering mechanism. The technology, used in a leading manufacturer’s mini-pleat and v-bank filters, supplements the mechanical blocking of particles on the filter surface by capturing particles throughout the depth of the filter. Additionally, in many circumstances these filters allow the filter configuration to be changed from a pre- and post-filter setup to just a single filter; this does not impact air quality and can dramatically improve energy efficiency. 

Electret-enhanced filters also improve pressure drop over conventional filters. More air can pass through while trapping particles, so the air movement system consumes less energy. Finally, these electret-enhanced filters can be changed less frequently (once to twice per year depending on filter type) and many do not require a pre-filter.

While high-performance filters may have a higher up-front cost, the energy savings and performance improvements that enable free air cooling in the data center more than make up for the investment.

CABLING

Flat, foldable copper cable assemblies can save space and reduce airflow blockage, while low-power active optical cable assemblies cut energy use.

Typically, data centers utilize a mix of passive optical copper cables and fiber active optical cables (AOCs). Passive copper cables are preferred for short reaches because of their affordability, whereas AOC cables have been used most often for reaches of more than five meters. Both types of cables affect data center efficiency in different ways, but new innovations in copper cables and AOCs can improve energy consumption across the board.

Copper twin axial cables are the standard for short-reach interconnect applications in data centers, though they tend to be bulky and difficult to route due to their generous bend radius requirements. However, a recent development in manufacturing technology has led to a thin, foldable, ribbon-style twin axial cable for both internal and external applications. This new slim cable is only .88 mm thick for a single unjacketed ribbon of 30 AWG (American wire gauge) cable and 3 mm thick for a jacketed eight-pair cable, compared to 9 to 10 mm for a typical twin axial cable.

The ribbon-style cable can be routed to enable complex, high-performance architectures while supporting speeds of 40 Gbps (10 Gbps per channel), which is not possible with conventional twin axial cables. Previously, installers avoided bending cables significantly as they were at risk of degrading signal performance. However, the new cable’s longitudinal shielding construction allows it to bend and fold tightly without significantly impacting signal integrity, leading to better airflow, higher density, and reduced data center cooling requirements.

AOCs affect efficiency differently: the bend-insensitive fiber cable is terminated with a connector and embedded within a transceiver, which directly produces heat and consumes energy. Lower-power AOC cable assemblies and transceivers are more critical than ever as data center operators strive to lower carbon footprint and energy costs. With this in mind, cable assembly manufacturers are developing increasingly efficient AOC interconnects.

The most energy-efficient 40 Gbps-capable AOC available is one manufacturer’s QSFP+ AOC, which uses approximately 475 mW per end. Under certain assumed circumstances, this cable alone could save more than $429,000 a year in data center energy costs compared to other leading AOCs.* Beyond lowering power consumption directly, low-power AOCs also release less heat, further driving down power consumption by reducing the need for cooling.

Upgrades to copper cabling and AOCs are easy improvements that yield higher data center efficiency.

FIRE SUPPRESSION

Fluorinated ketone clean agents improve performance, safety, and sustainability.

There is growing recognition of the benefits of clean-agent fire suppression systems for data centers to avoid damage from water-based sprinkler systems and move away from non-sustainable clean agents. The traditional water-based sprinkler systems are safe for people and the environment, but can destroy sensitive electronic equipment. Sprinkler systems also require equipment to be powered down, leading to significant downtime and potential data loss.

On the other hand, clean fire suppression agents, such as halocarbon compounds, inert gases, and carbon dioxide, were created specifically for environments with mission-critical, high-value electronic equipment. They are non-corrosive and non-conductive, so they won’t cause damage and don’t require equipment to be powered down when deployed. However, some clean agents are known for issues of safety and environmental sustainability.

For example, C0₂ depletes oxygen in air when suppressing fire, making it lethal to humans. While safer, inert gases require substantially higher quantities, resulting in a larger footprint. Halons were banned by the 1994 Montreal Protocol on substances that deplete the ozone layer and their replacement, hydrofluorcarbons (HFCs), are now under evaluation for affecting climate change.²

An innovative solution created in 2003 delivers performance, safety, and sustainability previously missing from other fire suppression options. The fluorinated ketone clean agent, FK-5-1-12, provides the largest margin of safety compared to other clean agents, does not deplete the ozone layer, and compared to HFCs, reduces climate impact by more than 99%. In fact, it has a global warming potential (GWP) of one — the lowest of any halocarbon alternative to halon — compared to HFC fire suppressants which range from 3,220 to 14,800.³  

FK-5-1-12 can improve data center efficiency on a practical level as well, requiring less space and adding less weight than other clean agents. For example, one cylinder filled with FK-5-1-12 clean agent replaces five carbon dioxide or six inert gas canisters. It also works extremely fast, reaching extinguishing levels in 10 seconds or less after deployment to better protect lives and assets while avoiding costly downtimes.

Taking a new look at fire suppression systems will positively impact data center performance, safety, and sustainability.

ACCESS CONTROL SYSTEMS

Save time and money with a flexible system that’s easy to operate.

There are savings opportunities in access control systems. When not suited to a facility’s specific needs, the access control system can result in significant data center inefficiency due to lost time.

Ideal systems should have a flexible architecture that is customizable, scalable, and third-party configurable to ensure easy set up and ongoing operation. In other words, better efficiency. Data center operators should select access control systems with three key capabilities to ensure improved efficiency.

First, a high level of configuration will generate facility-specific reports and alerts, reducing time spent on data management work and enabling faster reactions to any issues that arise. Operators should also choose access control systems that can add on devices, such as cameras, barcode scanners, and magnetic strip readers. The add-on feature allows the system to incorporate future technologies and provides varying user authentication methods.

The final capability of an efficient access control system is simple user and group access rights management. As personnel and general access rights change, data center operators can make the changes in the system quickly. Speed is especially important in multi-tenant data centers.

When seeking novel ways to improve efficiency, a new access control system could save both time and money.

EVAPORATIVE IMMERSION COOLING

New, simplified immersion technology can cut data center cooling costs by 95% and shrink footprint by 90%.

Air cooling is often one of the greatest efficiency-limiting barriers in a data center. In fact, air conditioning and fans often exceed the power consumed by the IT equipment itself, averaging a remarkable 38% of total electricity consumed by the data center.⁴Airflow space requirements also exceed the space occupied by the hardware, further affecting energy efficiency.

Designed to overcome these challenges with air cooling, evaporative liquid immersion cooling is emerging as a trend in effective and efficient data centers. This new technology can enable an increase in power density up to 225 kW per rack to dramatically decrease the footprint while reducing data center cooling costs by more than 95%.^5,6So, how does it work?

Evaporative immersion cooling submerges the servers in a non-corrosive, non-conductive fluid that literally boils off the heat generated by electronic devices. Though this approach has been used for decades to cool high-value electronics, such as radar systems and transformers, most servers are currently optimized for air cooled architectures. With immersion cooling, one liter of fluid can cool 4kW of power — the average power requirement of standard 19 in. racks today. As the constraints of air cooling are lifted off of server manufacturers and as the demand for computer power increases, there will likely be a trend towards higher powered servers that can fully take advantage of immersion cooling.

Although evaporative immersion cooling in data centers is still in a burgeoning phase, commercial and proof-of-concept systems are being built around the world that will simplify tank designs and make hardware more accessible. These installations are laying the groundwork for engineers to design hardware with any density and without energy efficiency and air flow space limitations. While still in early stages, this exciting trend could lead to a dramatic improvement in data center energy efficiency and density.

CONCLUSION

As faster processing demands only increase the pressure on high-performing data centers, it is more important than ever for operators to ensure that data centers are working as efficiently and cost-effectively as possible. Many data centers have found ways to reduce costs, maximize space usage, and lower carbon footprints, but additional efficiencies are still available in some unexpected places. Whether using a new air filter or a installing a foldable copper cable, consider these five ways to achieve more with less.

*Based on a hypothetical scenario with the following assumptions: Infiniband high-performance computing environment with 10,000 QSFP+ AOC ports operating 24-hours per day; electricity cost of $0.08 per kilowatt hour. Five AOCs from leading AOC manufacturers were evaluated using data from 2012 public/published records. Estimated annual savings ranged from $114,000 to $429,000.

WORKS CITED

1. “2011 Gaseous and Particulate Contamination Guidelines For Data Centers.” Whitepaper, American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc., 2011.

2. “United States, China, and Leaders of G-20 Countries Announce Historic Progress Toward a Global Phase Down of HFCs.” Press release, White House Office of the Press Secretary, Sept. 6, 2013.

3. “Environmental Properties of 3M™ Novec™1230 Fire Protection Fluid.” Technical brief, 3M Company, 2004.

4. “Energy Efficient Cooling Solutions for Data Centers.” Whitepaper, Liebert and Emerson Network Power, 2007.

5. “Playing it cool: New immersion cooling process could lead to 90% reductions in data center energy usage for cooling.” Article, 3M Company, 2012.

6. “3M, SGI and Intel Showcase Advanced Cooling Technology for the Data Center of the Future.” 3M Company, 2014. Accessed June 18, 2014.