Top 5 Trends in Data Center Energy Efficiency

In 2007, the US Environmental Protection Agency delivered its Report to Congress on Server and Data Center Efficiency Opportunities, in which they stated that the nation s data centers accounted for 1.5% of the total electrical consumption in the United States, or about 61 billion kilowatt-hours (kwh). Since the release of this report, the focus on efficiency and sustainability in the data center has risen exponentially with product and design innovation, government programs focused on data center efficiency, utility company incentives, and most importantly, owner commitment to improving the efficiency of their data center operations. As with any great dialogue, there are varying opinions on what constitutes an energy efficient data center and what strategies yield the most significant reductions in energy consumption. Every data center environment is unique, and the methodologies selected to improve efficiency in your data center should be developed specific to the design conditions of your existing environment, your tolerance for change in the data center, and the projected Return on Investment (ROI) realized from the selected upgrades. However, because most data centers on average are 10 years old, there are a number of changes that can be made that will improve efficiency and reduce operating costs. Increased Supply Air Temperature One of the most impactful efficiency improvements that you can make in your data center is often times the easiest to implement increasing your supply air temperature set point. ASHRAE TC9.9 2008 expanded the envelope for recommended operating conditions in the data center; this widened envelope increased the upper limit of the recommended temperature range in the data center from 77 F to 80.6 F (see Figure 1). Given that most data centers today operate in the 68 F to 72 F temperature range 1, substantial efficiency increases can be made through adjustments to your supply air temperature. Every degree you are able to increase your supply air temperature will yield an approximate energy savings of 3%-4%, and many organizations are taking steps to implement these temperature set point changes. Before making any changes to your supply air set points, it is important to ensure that you are measuring temperature in the right locations. It is critical that your supply air temperature in the data center represents the temperature at the server intake only. Many legacy data centers measure temperature via wall-mounted thermostats, which inaccurately represent the actual temperature of the air at the server intake locations. If necessary, relocate temperature monitors to the front of your data center racks before adjusting your set points. In addition, it is recommended that you implement the changes incrementally (one or two degrees at a time) in order to properly monitor the impact that it will have on the environmental condition of your 2004 Version 2008 Version Low End Tempature 20 C [68 F] 18 C [64.4 F] High End Tempature 25 C [77 F] 27 C [80.6 F] Low End Tempature 40% RH 5.5 C DP [41.9 F DP] High End Tempature 50% RH 60% RH &15 C DP [59 F DP) Figure 1. 2004 vs. 2008 Operating Envelope Copyright 2012 Leading Edge Design Group www.ledesigngroup.com 2

data center, as a legacy data center facility is likely not configured to support the upper limits of this temperature threshold. Containment & Airflow Management In order to fully take advantage of the efficiencies of increased supply air temperatures, it is necessary to separate cool supply air from hot exhaust air in the data center. Any mixing of these two air streams leads to inefficiencies and impacts the redundancy and capacity of your Computer Room Air Conditioners (CRAC). The practice of proper airflow management is starting to become more widely accepted by data center operators and many are adopting best practices like Hot Aisle Cold Aisle orientations and blanking panels. Further increases in efficiency can be realized through the implementation of containment, which physically separates supply and exhaust air in the data center. There is considerable debate between which containment strategy Hot Aisle Containment (HACS) or Cold Aisle Containment (CACS) is the most efficient and effective for the data center. Hot Aisle containment seeks to capture hot exhaust air from IT equipment and return it to CRAC (or CRAH 2 ) units as quickly as possible. Cold Aisle Containment isolates cool supply air for IT equipment only, providing an even and consistent supply air temperature at the server intake. In a retrofit application, the best and most cost-effective strategy will depend on your existing environment. Available containment solutions range from plastic containment curtains (similar to what you would find in a grocery store freezer) to fully contained rooms with doors, walls, and a roof. Before selecting a containment solution, careful consideration should be given to the design intent of your data center, existing airflow paths, existing data center equipment, and your local codes 3. When properly implemented, containment solutions can reduce energy costs in the data center by 5% to 10% and can deliver a typical payback of less than two years 4. Figure 2. Water-side Free Cooling Map (Available Hours where Wet Bulb Tempature 10 C [50 F]) Figure 3. Air-side Free Cooling Map (Available Hours where Dry Bulb Tempature 27 C [81 F] AND Dew Point 15 C [59 F]) Economization Economization, or free cooling, has become the most extensively discussed topic regarding data center efficiency, especially with companies like Facebook recently completing data centers that operate with 100% free cooling. Both forms of free cooling, air-side economizers and water-side economizers, provide significant reductions in energy costs for data center operators by taking advantage of favorable environmental (temperature and humidity) conditions. Copyright 2012 Leading Edge Design Group www.ledesigngroup.com 3

Water-side or indirect economizers utilize outside air to cool the water supplied to the chiller, reducing or eliminating the need for the chiller compressors to do so. In retrofit applications, water-side economizers are best suited for data centers that have existing chilled water plants and, more importantly, are in locations where the wet bulb temperature is less than 55 F for 3,000 hours per year or more (this condition is applicable to the majority of the United States, see Figure 2). In data centers that meet these criteria, water-size economizers can be economically retrofitted. Moreover, when operating in water-size economizer mode, the costs of a data center chiller plant can be reduced by up to 70%4. Air-side or direct economizers supply outside air to the data center whenever environmental conditions are appropriate. Exhaust air from IT equipment is typically directed outside. Similar to water-side economizers, location is a critical design element in evaluating the feasibility of implementing air-side economization (see Figure 3). Air-side economizers are typically not a cost-effective retrofit given the complexity in design, infrastructure, and commissioning of the control systems. However, with minimum savings of up to 30% 4 over traditional data centers, new data center builds should consider the potential of implementing air-side economization. Conclusion IT equipment in the data center environment is constantly evolving, and the process of maintaining an energy efficient data center is an ongoing effort. If you have an existing data center that you seek to improve, it is important to first establish and accurately measure your energy usage today. Once you understand this baseline, outline your path for improvement, set goals for energy reductions, and track the progress of your investments against your total energy usage, total energy cost, and metrics like Power Usage Effectiveness (PUE). The best plans for implementing energy efficiency improvements in the data center are incremental and focus first on small changes with low operational impact while having a well-defined path to leverage more complex upgrades like containment or economization going forward. If you are building a new data center, it is important to include energy efficiency as a critical element in the programming or requirements definition stages of your design. Your design team should be able to assist you in defining goals for your data center efficiency as well as to help you understand the cost implications and ROI of implementing energy efficient infrastructures and equipment. Your data center goals, size, budget, location, and lifecycle will help dictate what strategies are most appropriate for your design. Notes 1. Source: IDC 2. CRAH: Computer Room Air Handler 3. A fully contained room will likely require adjustments for fire detection and suppression. Check with your local Authority Having Jurisdiction (AHJ) to determine requirements 4. Source energystar.gov Copyright 2012 Leading Edge Design Group www.ledesigngroup.com 4

Insights on Utility Company Incentives Utility company budgets for energy efficiency incentives are increasing, but so are the challenges that the utilities face in reaching their savings goals. The great news for data center owners and operators is that utility company support for data center incentives is becoming more widespread, creating a much-needed alignment between the data center efficiency goals of the public and private sector with the availability of financial incentives to help improve the ROI of a data center upgrade. The process of applying for and earning incentives is not an easy one, but significant incentives are available and should be pursued. These incentives can help reduce the capital expense of building a new data center or, moreover, can help increase the ROI of renovating your existing data center to make it more energy efficient. Most times, renovating your data center will improve your ability to support high-density loads, free up available white space, and extend the lifecycle of your existing data center footprint. Earning a utility company incentive to do so could be the financial support that helps provide solidify the right ROI to help your project move forward. While there are some utility companies that have created (or are working to create) prescriptive programs for data centers, the majority of data center projects will fall under the custom measures category, meaning that the utility will need to look at the potential savings and associated costs of each project individually before an incentive can be calculated. Knowing this, there are a few important things to keep in mind when preparing to apply for a data center incentive: 1. Be Prepared To Commit Data Center projects, whether new construction or renovation, are extremely time intensive. Adding an application for a utility company incentive for your data center project will add to the resource commitment required from your organization. Ensure that there is a single point of contact responsible for the communication related to the incentive application and build the time requirements and milestones into your overall project schedule. 2. Involve The Utility Company Early Utility companies would rather give you an incentive than a rebate, meaning they generally prefer help influence your design decisions and your equipment choices before you purchase them. Their representatives are a great resource that can help you understand the financial and environmental impacts of your design decision. Having them involved early helps you make informed decisions about your design as they relate to the energy-related ROI and the potential impact on your incentive. 3. Understand What You Have No one knows your data center like you do and all stakeholders involved in creating an incentive application have to rely on you as the end user to provide accurate information about your environment. This includes both IT equipment and physical infrastructure equipment. At minimum, you can get a head start by collecting specification sheets on existing equipment (like your CRACs), checking purchasing records to understand their age, and taking a snapshot of the existing system parameters (i.e. entering water temperature, supply air temperature, delta T). 4. Involve A Resource That Understands The Programs This may be an on staff resource or an outside consultant, but engaging resources that have experience with the programs and that understand the information required by the utility companies specific to data center projects will help expedite the process and ensure that your incentive is maximized. The right resource will help create an accurate baseline that your data center will be compared against, and this requires a knowledge of both data center infrastructures/design and utility company programs. The math is important the utility companies have to justify their savings estimates and any project can be audited, so attention to detail is critical. 5. Get Organizational Buy In Most often choosing the most efficient designs and products involves a greater up front capital expenditure. The utility company incentive can help offset this, but it is critical to look at the overall TCO of the project to understand the long-term savings your organization will achieve by investing in an efficient data center design. It is better to have the organizational support in advance, and most often choosing to prioritize efficiency in the data center will align well with overall corporate strategy for the environmental impact of your operations. Copyright 2012 Leading Edge Design Group www.ledesigngroup.com 5

About Leading Edge Design Group is a leading national provider of energy optimization services that delivers significant energy savings to the public and private marketplaces through efficient data center designs and emerging LED lighting and wireless lighting control technologies. Founded in 2007 with the goal of pursuing, promoting, and providing the finest energy optimization solutions available, we help our customers minimize the environmental impact of their businesses while improving operational reliability and reducing costs. Leading Edge Design Group is dedicated to encouraging, challenging, and contributing to energy industry innovation with an ongoing commitment to our community and our environment. Visit us at www.ledesigngroup.com and connect with us on Twitter @ledesigngroup. Contact LED Headquarters 86 Chosen Vale Lane Suite 201 Enfield, NH 03748 Phone: 603.632.4507 Fax: 603.632.4559 www.ledesigngroup.com Copyright 2012 Leading Edge Design Group www.ledesigngroup.com 6