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78 result(s) found.

Number	Title & Abstract
WP-153 v0	Implementing Hot and Cold Air Containment in Existing Data Centers Containment solutions can eliminate hot spots and provide energy savings over traditional uncontained data center designs. The best containment solution for an existing facility will depend on the constraints of the facility. While ducted hot aisle containment is preferred for highest efficiency, cold aisle containment tends to be easier and more cost effective for facilities with existing raised floor air distribution. This paper investigates the constraints, reviews all available containment methods, and provides recommendations for determining the best containment approach.
WP-179 v0	Data Center Temperature Rise During a Cooling System Outage The data center architecture and its IT load significantly affect the amount of time available for continued IT operation following a loss of cooling. Some data center trends such as increasing power density, warmer supply temperatures, the “right-sizing” of cooling equipment, and the use of air containment may actually increase the rate at which data center temperatures rise. However, by placing critical cooling equipment on backup power, choosing equipment with shorter restart times, maintaining adequate reserve cooling capacity, and employing thermal storage, power outages can be managed in a predictable manner. This paper discusses the primary factors that affect transient temperature rise and provides practical strategies to manage cooling during power outages.
WP-178 v0	A Framework for Developing and Evaluating Data Center Maintenance Programs Inadequate maintenance and risk mitigation processes can quickly undermine a facility’s design intent. It is, therefore, crucial to understand how to properly structure and implement an operations and maintenance (O&M) program to achieve the expected level of performance. This paper defines a framework, known as the Tiered Infrastructure Maintenance Standard (TIMS), for aligning an existing or proposed maintenance program with a facility’s operational and performance requirements. This framework helps make the program easier to understand, communicate, and implement throughout the organization.
WP-1000 v0	Schneider Electric White Paper App: Download Instructions and FAQs With millions of downloads every year, Schneider Electric’s fact-based, vendor-neutral white papers are a highly respected information source. Schneider Electric’s white paper library can now be conveniently stored, read and updated on your smart phone or tablet. This paper explains how to download and install the App for both iOS (e.g., iPhone, iPad, iPod Touch) and Android (e.g., Samsung Infuse, Motorola Zoom) devices.
WP-139 v0	Cooling Entire Data Centers Using Only Row Cooling Row cooling is emerging as a practical total cooling solution for new data centers due to its inherent high efficiency and predictable performance. Yet some IT equipment in data centers appears incompatible with row cooling because it is not arranged in neat rows due to the nature of the equipment or room layout constraints, suggesting the ongoing need for traditional perimeter cooling to support these loads. This paper explains how a cooling system comprised only of row coolers, with no room cooling system, can cool an entire data center, including IT devices that are not in neat rows.
WP-250 v0	Guide for Reducing Data Center Physical Infrastructure Energy Consumption in Federal Data Centers In an effort to create a clean energy economy, recent US presidents and congress have issued a series of legislation and executive orders requiring federal agencies to increase energy efficiency and reduce carbon emissions in government facilities. Vivek Kundra, Federal Chief Information Officer, is supporting that effort by establishing a Federal Data Center Consolidation Initiative to help reduce energy consumption in over 1, 100 Federal data centers. US Federal data center managers are on a timeline to respond with their final consolidation plan. This paper analyzes the implication of these mandates and offers recommendations for how to improve energy efficiency in Federal data centers. This paper is written for a US-only audience.
WP-170 v0	Avoiding Common Pitfalls of Evaluating and Implementing DCIM Solutions While many who invest in Data Center Infrastructure Management (DCIM) software benefit greatly, some do not. Research has revealed a number of pitfalls that end users should avoid when evaluating and implementing DCIM solutions. Choosing an inappropriate solution, relying on inadequate processes, and a lack of commitment / ownership / knowledge can each undermine a chosen toolset’s ability to deliver the value it was designed to provide. This paper describes these common pitfalls and provides practical guidance on how to avoid them.
WP-174 v0	Practical Options for Deploying IT Equipment in Small Server Rooms and Branch Offices Small server rooms and branch offices are typically unorganized, unsecure, hot, unmonitored, and space constrained. These conditions can lead to system downtime or, at the very least, lead to “close calls” that get management’s attention. Practical experience with these problems reveals a short list of effective methods to improve the availability of IT operations within small server rooms and branch offices. This paper discusses making realistic improvements to power, cooling, racks, physical security, monitoring, and lighting. The focus of this paper is on small server rooms and branch offices with up to 10kW of IT load.
WP-164 v0	TCO Analysis of a Traditional Data Center vs. a Scalable, Containerized Data Center Standardized, scalable, pre-assembled, and integrated data center facility power and cooling modules provide a “total cost of ownership” (TCO) savings of 30% compared to traditional, built-out data center power and cooling infrastructure. Avoiding overbuilt capacity and scaling the design over time contributes to a significant percentage of the overall savings. This white paper provides a quantitative TCO analysis of the two architectures, and illustrates the key drivers of both the capex and opex savings of the improved architecture.
WP-4 v0	The Importance of Critical Site Documentation and Training All studies of downtime in mission-critical environments come to the same conclusion: human error is a leading cause. The most effective way to fight this threat to your business is with the double-edged sword of documentation and training. Properly trained facility personnel understand how the infrastructure works, how to operate and maintain it safely, and how to respond when the equipment does not function as expected. Thorough, accurate, and readily accessible documentation is both the foundation of this knowledge and the means to implement it. The establishment of a comprehensive documentation and training program is a crucial, but rarely achieved goal. This white paper describes the proper methodology for building an effective, organized program that addresses the special requirements of critical environments.
WP-2 v0	Top 10 Mistakes in Data Center Operations: Operating Efficient and Effective Data Centers How can you avoid making major mistakes when operating and maintaining your data center(s)? The key lies in the methodology behind your operations and maintenance program. All too often, companies put immense amounts of capital and expertise into the design of their facilities. However, when construction is complete, data center operations are an afterthought. This whitepaper explores the top ten mistakes in data center operations.
WP-136 v0	High Efficiency Economizer-based Cooling Modules for Large Data Centers When a cooling plant operates in economizer mode, high energy-consuming mechanical systems can be turned off. A standardized, modular cooling plant designed to operate primarily in economizer mode not only reduces costs but also improves predictability and flexibility. This paper shows a new approach to data center cooling that uses approximately half the energy of traditional methods, and at the same time provides greater scalability, availability, and ease of maintenance.
WP-151 v0	Review of Four Studies Comparing Efficiency of AC and DC Distribution for Data Centers DC is proposed for use in data centers as an alternative to AC distribution primarily based on publicized claims of efficiency improvements and energy savings. This paper shows that the most widely cited values for quantitative improvements are wrong and grossly overstate the efficiency differences between AC and DC, and that the latest AC and DC systems provide effectively the same efficiency. This paper compares the results of four different publicized studies and explains the assumptions and mistakes that have led to erroneous but widely circulated beliefs about the efficiency benefits of DC power distribution.
WP-147 v0	Data Center Projects: Advantages of Using a Reference Design It is no longer practical or cost-effective to completely engineer all aspects of a unique data center. Re-use of proven, documented subsystems or complete designs is a best practice for both new data centers and for upgrades to existing data centers. Adopting a well-conceived reference design can have a positive impact on both the project itself, as well as on the operation of the data center over its lifetime. Reference designs simplify and shorten the planning and implementation process and reduce downtime risks once up and running. In this paper reference designs are defined and their benefits are explained.
WP-160 v0	Specification of Modular Data Center Architecture There is a growing consensus that conventional legacy data center design will be superseded by modular scalable data center designs. Reduced total cost of ownership, increased flexibility, reduced deployment time, and improved efficiency are all claimed benefits of modular scalable designs. Yet the term “modular”, when and where modularity is appropriate, and how to specify modularity are all poorly defined. This paper creates a framework for modular data center architecture and describes the various ways that modularity can be implemented for data center power, cooling, and space infrastructure and explains when the different approaches are appropriate and effective.
WP-5 v0	A Practical Guide to Disaster Avoidance in Mission-Critical Facilities A disaster preparedness plan is crucial to organizations operating in 24/7/365 environments. With zero disruption the goal, management must carefully evaluate and mitigate risks to the physical infrastructure that supports the mission-critical facility. While business continuity planning typically addresses Information Technology, this paper reviews and discusses the requirements of the facility’s infrastructure as part of a comprehensive business continuity disaster plan. Without a proper disaster mitigation plan for the facility’s infrastructure, the overall business continuity plan is built on a risky foundation. If a natural, human, or technological disaster strikes your facility, are you and your infrastructure prepared? Does your organization have procedures in place to prepare for severe winter storms, earthquakes, tornados, hurricanes, or other disasters? Surviving tomorrow’s disaster requires planning today.
WP-7 v0	Maximizing Uptime in Mission-Critical Facilities As technology reaches into every corner of our world, the importance of, and reliance on, your mission critical facility reaches new heights. Uptime is no longer a lofty goal, it is an absolute necessity. However, uptime is not a product that you specify with the design of your facility, install, and then forget about. A facility designed to 99.99% of availability will not achieve / maintain that number, unless we fully understand the many factors that affect uptime. Maximum Uptime is a philosophy. It begins with the planning of your facility, and remains a continuous process through every step of design, construction, commissioning, operations, failure analysis, and recommissioning.
WP-171 v1	Considerations for Owning versus Outsourcing Data Center Physical Infrastructure When faced with the decision of upgrading an existing data center, building new, or leasing space in a retail colocation data center, there are both quantitative and qualitative differences to consider. The 10-year TCO may favor upgrading or building over outsourcing, however, this paper demonstrates that the economics may be overwhelmed by a business' sensitivity to cash flow, cash cross-over point, deployment timeframe, data center life expectancy, regulatory requirements, and other strategic factors. This paper discusses how to assess these key factors to help make a sound decision.
WP-129 v3	Comparing Data Center Power Distribution Architectures Significant improvements in efficiency, power density, power monitoring, and reconfigurability have been achieved in data center power distribution, increasing the options available for data centers. This paper compares five power distribution approaches including panelboard distribution, field-wired PDU distribution, factory-configured PDU distribution, floor-mount modular power distribution, and modular busway, and describes their advantages and disadvantages. Guidance is provided on selecting the best approach for specific applications and constraints.
WP-142 v2	Data Center Projects: System Planning Planning of a data center physical infrastructure project need not be a time consuming or frustrating task. Experience shows that if the right issues are resolved in the right order by the right people, vague requirements can be quickly translated into a detailed design. This paper outlines practical steps to be followed that can cut costs by simplifying and shortening the planning process while improving the quality of the plan.
WP-172 v1	Types of Electrical Meters in Data Centers There are several different types of meters that can be designed into a data center, ranging from high precision power quality meters to embedded meters (i.e. in a UPS or PDU). Each has different core functions and applications. This white paper provides guidance on the types of meters that might be incorporated into a data center design, explains why they should be used, and discusses the advantages and disadvantages of each. Example data centers are presented to illustrate where the various meters are likely to be deployed.
WP-81 v2	Site Selection for Mission Critical Facilities When selecting a new site or evaluating an existing site, there are dozens of risk factors that must be considered if optimal availability is to be obtained. Geographic, site-related, building, and economic risks need to be understood and mitigated to lessen the downtime effects on your business. In this paper guidelines are established for selecting a new site or assessing an existing one. Common risks that affect the availability of a business are defined and techniques for minimizing these risks are presented.
WP-130 v2	Choosing Between Room, Row, and Rack-based Cooling for Data Centers Latest generation high density and variable density IT equipment create conditions that traditional data center cooling was never intended to address, resulting in cooling systems that are oversized, inefficient, and unpredictable. Room, row, and rack-based cooling methods have been developed to address these problems. This paper describes these improved cooling methods and provides guidance on when to use each type for most next generation data centers.
WP-145 v1	The Top 9 Mistakes in Data Center Planning Why do so many data center builds and expansions fail? This white paper answers the question by revealing the top 9 mistakes organizations make when designing and building new data center space, and examines an effective way to achieve success through the Total Cost of Ownership (TCO) approach.
WP-104 v3	Classification of Data Center Infrastructure Management (DCIM) Tools Data centers today lack a formal system for classifying software management tools. As a result, confusion exists regarding which management systems are necessary and which are optional for secure and efficient data center operation. This paper divides the realm of data center management tools into four distinct subsets and compares the primary and secondary functions of key subsystems within these subsets. With a classification system in place, data center professionals can begin to determine which physical infrastructure management tools they need – and don’t need – to operate their data centers.
WP-150 v3	Power and Cooling Capacity Management for Data Centers High density IT equipment stresses the power density capability of modern data centers. Installation and unmanaged proliferation of this equipment can lead to unexpected problems with power and cooling infrastructure including overheating, overloads, and loss of redundancy. The ability to measure and predict power and cooling capability at the rack enclosure level is required to ensure predictable performance and optimize use of the physical infrastructure resource. This paper describes the principles for achieving power and cooling capacity management.
WP-118 v4	Virtualization and Cloud Computing: Optimized Power, Cooling, and Management Maximizes Benefits IT virtualization, the engine behind cloud computing, can have significant consequences on the data center physical infrastructure (DCPI). Higher power densities that often result can challenge the cooling capabilities of an existing system. Reduced overall energy consumption that typically results from physical server consolidation may actually worsen the data center’s power usage effectiveness (PUE). Dynamic loads that vary in time and location may heighten the risk of downtime if rack-level power and cooling health are not understood and considered. Finally, the fault-tolerant nature of a highly virtualized environment could raise questions about the level of redundancy required in the physical infrastructure. These particular effects of virtualization are discussed and possible solutions or methods for dealing with them are offered.
WP-107 v3	How Data Center Infrastructure Management Software Improves Planning and Cuts Operational Costs Business executives are challenging their IT staffs to convert data centers from cost centers into producers of business value. Data centers can make a significant impact to the bottom line by enabling the business to respond more quickly to market demands. This paper demonstrates, through a series of examples, how data center infrastructure management software tools can simplify operational processes, cut costs, and speed up information delivery.
WP-34 v3	Battery Technology for Data Centers and Network Rooms: Ventilation of Lead-Acid Batteries Lead-acid batteries are the most widely used method of energy reserve. Ventilation systems must address health and safety as well as performance of the battery and other equipment in a room. Valve regulated lead acid (VRLA) batteries and modular battery cartridges (MBC) do not require special battery rooms and are suitable for use in an office environment. Air changes designed for human occupancy normally exceed the requirements for VRLA and MBC ventilation. Vented (flooded) batteries, which release hydrogen gas continuously, require a dedicated battery room with ventilation separate from the rest of the building. This paper summarizes some of the factors and U.S. codes to consider when selecting and sizing a ventilation system for a facility in which stationary batteries are installed.
WP-31 v8	Battery Technology for Data Centers and Network Rooms: U.S. Fire Safety Codes Related to Lead Acid Batteries Fire safety regulations and their application to UPS battery installations are reviewed. In some cases, fire codes do not clearly recognize improvements in battery safety resulting from changing battery technology. Valve Regulated Lead Acid (VRLA) batteries are frequently deployed within data centers and network rooms without the need for the elaborate safety systems that are required for Vented (Flooded) Lead Acid batteries. Proper interpretation of the fire codes is essential in the design and implementation of data centers and network rooms.
WP-177 v2	Determining the Power, Cooling, and Space Capacities when Consolidating Data Centers When planning the consolidation of multiple data centers into existing data center(s), it is often difficult to establish the various capacities and capabilities of each site’s physical infrastructure. This information is a key input to deciding which site(s) will become the “receiving” data center(s). This paper describes how to specify these requirements in standard terms and how to establish current conditions and future capabilities of each data center involved in a consolidation project.
WP-176 v1	Energy Savings Performance Contracts for Federal Data Center Consolidation The cost of operating and maintaining federal agency data centers is extremely high. Mandates and initiatives have been put in place to address these costs through energy conservation, but with budgets already strained, the initial capital investment can be a daunting hurdle. This paper describes energy savings performance contracts (ESPCs), explains how to use them as an alternative financing option for consolidation projects, and provides examples.
WP-24 v3	Effect of UPS on System Availability This white paper explains how system availability and uptime are affected by AC power outages and provides quantitative data regarding uptime in real-world environments, including the effect of UPS on uptime.
WP-175 v1	Preparing the Physical Infrastructure of Receiving Data Centers for Consolidation The consolidation of one or more data centers into an existing data center is a common occurrence. This paper gives examples of what is becoming a standard architecture for preparing the physical infrastructure in the receiving data center. This approach allows for shorter timelines and high efficiency while avoiding the commonly expected difficulties and complexities often experienced with consolidation projects.
WP-161 v1	Allocating data center energy costs and carbon to IT users Are complicated software and instrumentation needed to measure and allocate energy costs and carbon to IT users? Or can we get by with simple, low cost methods for energy cost and carbon allocation? How precise do we need to be? This paper provides an overview of energy cost and carbon allocation strategies and their precision. We show that it is both easy and inexpensive for any data center, large or small, new or old, to get started allocating costs and carbon, but the expense and complexity escalate and ROI declines when excessive precision is specified.
WP-126 v1	An Improved Architecture for High-Efficiency, High-Density Data Centers Data center power and cooling infrastructure worldwide wastes more than 60, 000, 000 megawatt-hours per year of electricity that does no useful work powering IT equipment. This represents an enormous financial burden on industry, and is a significant public policy environmental issue. This paper describes the principles of a new, commercially available data center architecture that can be implemented today to dramatically improve the electrical efficiency of data centers.
WP-117 v1	Data Center Physical Infrastructure: Optimizing Business Value To stay competitive in today’s rapidly changing business world, companies must update the way they view the value of their investment in data center physical infrastructure (DCPI). No longer are simply availability and upfront cost sufficient to make adequate business decisions. Agility, or business flexibility, and low total cost of ownership have become equally important to companies that will succeed in a changing global marketplace.
WP-141 v1	Data Center Projects: Project Management In data center design/build projects, flaws in project management and coordination are a common – but unnecessary – cause of delays, expense, and frustration. The ideal is for project management activities to be structured and standardized like interlocking building blocks, so all parties can communicate with a common language, avoid responsibility gaps and duplication of effort, and achieve an efficient process with a predictable outcome. This paper presents a framework for project management roles and relationships that is understandable, comprehensive, and adaptable to any size project.
WP-140 v1	Data Center Projects: Standardized Process As the design and deployment of data center physical infrastructure moves away from art and more toward science, the benefits of a standardized and predictable process are becoming compelling. Beyond the ordering, delivery, and installation of hardware, any build or upgrade project depends critically upon a well-defined process as insurance against surprises, cost overruns, delays, and frustration. This paper presents an overview of a standardized, step-by-step process methodology that can be adapted and configured to suit individual requirements.
WP-154 v2	Electrical Efficiency Measurement for Data Centers Data center electrical efficiency is rarely planned or managed. The unfortunate result is that most data centers waste substantial amounts of electricity. Today it is both possible and prudent to plan, measure, and improve data center efficiency. In addition to reducing electrical consumption, efficiency improvements can gain users higher IT power densities and the ability to install more IT equipment in a given installation. This paper explains how data center efficiency can be measured, evaluated, and modeled, including a comparison of the benefits of periodic assessment vs. continuous monitoring.
WP-138 v1	Energy Impact of Increased Server Inlet Temperature The quest for efficiency improvement raises questions regarding the optimal air temperature for data centers. The ASHRAE TC-9.9 committee has recently adopted an extension of the recommended thermal envelope for server inlet temperature and humidity. A popular hypothesis suggests that total energy demands should diminish as the server inlet temperatures increase. This paper tests that hypothesis through the development of a composite power consumption baseline for a mixture of servers as a function of inlet temperature and applying this data to a variety of cooling architectures.
WP-158 v2	Guidance for Calculation of Efficiency (PUE) in Data Centers Before data center infrastructure efficiency can be benchmarked using PUE or other metrics, there must be agreement on exactly what power consumptions constitute IT loads, what consumptions constitute physical infrastructure, and what loads should not be counted. Unfortunately, commonly published efficiency data is not computed using a standard methodology, and the same data center will have different efficiency ratings when different methodologies are applied. This paper explains the problem and describes a standardized method for classifying data center loads for efficiency calculations.
WP-38 v1	Harmonic Currents in the Data Center: A Case Study This document provides an overview of how problems related to harmonic neutral currents are mitigated by load diversity, with specific focus on Information Technology data center environments. Detailed measurements of an actual operating data center are presented. This case study illustrates the way that load diversity mitigates harmonic current levels, lowers shared neutral current in multi-wire feeders and branch circuits, and improves total circuit power factor.
WP-44 v4	Improving Rack Cooling Performance Using Airflow Management Blanking Panels Unused vertical space in open frame racks and rack enclosures creates an unrestricted recycling of hot air that causes equipment to heat up unnecessarily. The use of airflow management blanking panels can reduce this problem. This paper explains and quantifies the effects of airflow management blanking panels on cooling system performance.
WP-16 v1	Protection of RS-232 Serial Connections This white paper explains the special power protection issues related to RS-232 cabling. First, the special vulnerabilities of RS-232 cabling are explained. Then appropriate protection and mitigation techniques are provided.
WP-9 v2	Common Mode Susceptibility of Computers This white paper examines and challenges the claims made in literature regarding the alleged high susceptibility of computers to common mode noise.
WP-8 v2	Inter-system Ground Noise: Causes and Effects Many power-related problems are the result of Inter-System Ground Noise. This problem cannot be corrected using typical AC-only power protection equipment. The cause and solution of Inter-System Ground Noise problems are described.
WP-19 v2	Re-examining the Suitability of the Raised Floor for Data Center Applications The circumstances that gave rise to the development and use of the raised floor in the data center environment are examined. Many of the reasons for the raised floor no longer exist, and the problems associated with raised floors suggest that their widespread use is no longer justified or desirable for many applications.
WP-125 v2	Strategies for Deploying Blade Servers in Existing Data Centers When blade servers are densely packed, they can exceed the power and cooling capacities of almost all traditional data centers. This paper explains how to evaluate the options and select the best power and cooling approach for a successful and predictable blade deployment.
WP-15 v1	Watts and Volt-Amps: Powerful Confusion This note helps explain the differences between Watts and VA and explains how the terms are correctly and incorrectly used in specifying power protection equipment.
WP-27 v3	Efficiency and Other Benefits of 208 Volt Over 120 Volt Input for IT Equipment Decisions made regarding the distribution of 208V or 120V power to IT equipment can significantly impact overall efficiency of the data center. This paper explores the voltage connection options of 208 volt (V) and 120V for servers in North America and considers the efficiency implications of these choices. This same discussion applies to the use of 200V vs. 100V in Japan.
WP-128 v2	High-Efficiency AC Power Distribution for Green Data Centers The use of 240 volt power distribution for data centers saves floor space, simplifies power cabling, saves capital cost, reduces weight, and increases electrical efficiency. This paper describes the various con-figurations for this distribution architecture and quantifies the benefits for the optimal configuration. Note: The methods in this paper only apply in North America and are for problems that are unique to North America.
WP-29 v6	Rack Powering Options for High Density Alternatives for providing electrical power to high density racks in Data Centers and Network Rooms are explained and compared. Issues addressed include quantity of feeds, single-phase vs. three-phase, number and location of circuit breakers, overload, selection of plug types, selection of voltage, redundancy, and loss of redundancy. The need for the rack power system to adapt to changing requirements is identified and quantified. Guidelines are defined for rack power systems that can reliably deliver power to high density loads while adapting to changing needs.
WP-28 v1	Rack Powering Options for High Density in 230VAC Countries Alternatives for providing electrical power to high density racks in data centers and network rooms are explained and compared. Issues addressed include quantity of feeds, single-phase vs. three-phase, number and location of circuit breakers, overload, selection of connector types, selection of voltage, redundancy, and loss of redundancy. The need for the rack power system to adapt to changing requirements is identified and quantified. Guidelines are defined for rack power systems that can reliably deliver power to high density loads while adapting to changing needs.
WP-23 v1	Reliability Models for Electric Power Systems This white paper explains the sources of downtime in electric power systems and provides an explanation for site-to-site variations in power availability. The factors affecting power quality from generation to the utilization point are summarized. There is a qualitative description of a model, which can be combined with data to provide a method for estimating down time based on site-related factors.
WP-120 v1	Guidelines for Specification of Data Center Power Density Conventional methods for specifying data center density are ambiguous and misleading. Describing data center density using Watts / ft2 or Watts / m2 is not sufficient to determine power or cooling compatibility with high density computing loads like blade servers. Historically there is no clear standard way of specifying data centers to achieve predictable behavior with high density loads. An appropriate specification for data center density should assure compatibility with anticipated high density loads, provide unambiguous instruction for design and installation of power and cooling equipment, prevent oversizing, and maximize electrical efficiency. This paper describes the science and practical application of an improved method for the specification of power and cooling infrastructure for data centers.
WP-35 v3	Battery Technology for Data Centers and Network Rooms: Lifecycle Costs The lifecycle cost of different UPS battery technologies is compared. The costs associated with the purchase of batteries, the infrastructure costs, and the costs associated with inflexibility to meet changing requirements are discussed and quantified.
WP-17 v1	Understanding Power Factor, Crest Factor, and Surge Factor This white paper explains the technical terms of power factor, crest factor, and surge factor. The use of these terms in specifying UPS is explained.
WP-25 v3	Calculating Total Cooling Requirements for Data Centers This document describes how to estimate heat output from Information Technology equipment and other devices in a data center such as UPS, for purposes of sizing air conditioning systems. A number of common conversion factors and design guideline values are also included.
WP-40 v3	Cooling Audit for Identifying Potential Cooling Problems in Data Centers The compaction of Information Technology equipment and simultaneous increases in processor power consumption are creating challenges for data center managers in ensuring adequate distribution of cool air, removal of hot air and sufficient cooling capacity. This paper provides a checklist for assessing potential problems that can adversely affect the cooling environment within a data center.
WP-11 v3	Explanation of Cooling and Air Conditioning Terminology for IT Professionals As power densities continue to increase in today’s data centers, heat removal is becoming a greater concern for the IT professional. Unfortunately, air conditioning terminology routinely used in the cooling industry is unnecessarily complicated. This complexity makes it difficult and frustrating for IT professionals to specify cooling requirements and even makes it difficult to discuss current cooling system performance with contractors, engineers, and maintenance personnel. This paper explains cooling terms in common language, providing an essential reference for IT professionals and data center operators.
WP-6 v4	Determining Total Cost of Ownership for Data Center and Network Room Infrastructure An improved method for measuring total cost of ownership (TCO) of data center and network room physical infrastructure and relating these costs to the overall Information Technology infrastructure is described, with examples. The cost drivers of TCO are quantified. The largest cost driver is shown to be unnecessary unabsorbed costs resulting from the oversizing of the infrastructure.
WP-114 v1	Implementing Energy Efficient Data Centers Electricity usage costs have become an increasing fraction of the total cost of ownership (TCO) for data centers. It is possible to dramatically reduce the electrical consumption of typical data centers through appropriate design of the network-critical physical infrastructure and through the design of the IT architecture. This paper explains how to quantify the electricity savings and provides examples of methods that can greatly reduce electrical power consumption.
WP-1 v7	The different types of UPS systems There is much confusion in the marketplace about the different types of UPS systems and their characteristics. Each of these UPS types is defined, practical applications of each are discussed, and advantages and disadvantages are listed. With this information, an educated decision can be made as to the appropriate UPS topology for a given need.
WP-55 v3	The Different Types of Air Distribution for IT Environments There are nine basic approaches to distribute air in data centers and network rooms. These approaches vary in performance, cost, and ease of implementation. These approaches are described along with their various advantages. The proper application of these air distribution types is essential knowledge for Information Systems personnel as well as Facilities Managers.
WP-37 v7	Avoiding Costs From Oversizing Data Center and Network Room Infrastructure The physical and power infrastructure of data centers and network rooms is typically oversized by more than 100%. Statistics related to oversizing are presented. The costs associated with oversizing are quantified. The fundamental reasons why oversizing occurs are discussed. An architecture and method for avoiding oversizing is described.
WP-157 v1	Eco-mode: Benefits and Risks of Energy-saving Modes of UPS Operation Many newer UPS systems have an energy-saving operating mode known as “eco-mode” or by some other descriptor. Nevertheless, surveys show that virtually no data centers actually use this mode, because of the known or anticipated side-effects. Unfortunately, the marketing materials for these operating modes do not adequately explain the cost / benefit tradeoffs. This paper shows that eco-mode provides a reduction of approximately 2% in data center energy consumption and explains the various limitations and concerns that arise from eco-mode use. Situations where these operating modes are recommended and contra-indicated are also described.
WP-59 v2	The Different Technologies for Cooling Data Centers There are 13 basic heat removal methods to cool IT equipment and to transport unwanted heat to the outdoor environment. This paper describes these fundamental cooling technologies using basic terms and diagrams. 11 of these methods rely on the refrigeration cycle as the primary means of cooling. Pumped refrigerant systems provide isolation between the primary heat removal system and IT equipment. The direct air and indirect air methods rely on the outdoor conditions as the primary means cooling making them more efficient for mild climates. The information in this paper allows IT professionals to be more involved in the specification of precision cooling solutions that better align with IT objectives.
WP-87 v2	Grounding and the Use of the Signal Reference Grid in Data Centers Signal reference grids are automatically specified and installed in data centers despite the fact that they are no longer needed by modern IT equipment. Even when installed, they are typically used incorrectly. This paper explains the origins of the signal reference grid, the operating principles and limitations, and why they no longer are needed.
WP-127 v3	A Quantitative Comparison of High Efficiency AC vs. DC Power Distribution for Data Centers This paper presents a detailed quantitative efficiency comparison between the most efficient DC and AC power distribution methods, including an analysis of the effects of power distribution efficiency on the cooling power requirement and on total electrical consumption. The latest high efficiency AC and DC power distribution architectures are shown to have virtually the same efficiency, suggesting that a move to a DC-based architecture is unwarranted on the basis of efficiency.
WP-108 v3	Making Large UPS Systems More Efficient As energy resources become scarcer and more expensive, electrical efficiency is becoming a more important performance factor in the specification and selection of large UPS systems. There are three subtle but significant factors that can materially affect a company’s cost of operating a UPS system and particularly the electrical bill. Unfortunately, the people who specify systems often fail to recognize these factors, which leads to increased costs to the owner because operational efficiencies are not correctly considered. This paper discusses the common errors and misunderstandings in evaluating UPS efficiency. UPS efficiency curves are explained, compared, and their cost implications quantified.
WP-163 v1	Containerized Power and Cooling Modules for Data Centers Standardized, pre-assembled and integrated data center facility power and cooling modules are at least 60% faster to deploy, and provide a first cost savings of 13% or more compared to traditional data center power and cooling infrastructure. Facility modules, also referred to in the data center industry as containerized power and cooling plants, allow data center designers to shift their thinking from a customized “construction” mentality to a standardized “site integration” mentality. This white paper compares the cost of both scenarios, presents the advantages and disadvantages of each, and identifies which environments can best leverage the facility module approach.
WP-58 v2	Humidification Strategies for Data Centers and Network Rooms The control of humidity in Information Technology environments is essential to achieving high availability. This paper explains how humidity affects equipment and why humidity control is required. Quantitative design guidelines for existing and new computing installations are discussed. Alternative methods to achieve desired humidity are described and contrasted. The difficult issue of how and where humidity should be measured is explained. The hidden costs associated with over-humidification are described.
WP-79 v1	Technical comparison of On-line vs. Line-interactive UPS designs UPS systems below 5000VA are available in two basic designs: line-interactive or double-conversion on-line. This paper describes the advantages and disadvantages of each topology and addresses some common misconceptions about real-world application requirements.
WP-135 v2	Impact of Hot and Cold Aisle Containment on Data Center Temperature and Efficiency Both hot-air and cold-air containment can improve the predictability and efficiency of traditional data center cooling systems. While both approaches minimize the mixing of hot and cold air, there are practical differences in implementation and operation that have significant consequences on work environment conditions, PUE, and economizer mode hours. The choice of hot-aisle containment over cold-aisle containment can save 43% in annual cooling system energy cost, corresponding to a 15% reduction in annualized PUE. This paper examines both methodologies and highlights the reasons why hot-aisle containment emerges as the preferred best practice for new data centers.
WP-124 v1	Preventive Maintenance Strategy for Data Centers In the broadening data center cost-saving and energy efficiency discussion, data center physical infrastructure preventive maintenance (PM) is sometimes neglected as an important tool for controlling TCO and downtime. PM is performed specifically to prevent faults from occurring. IT and facilities managers can improve systems uptime through a better understanding of PM best practices. This white paper describes the types of PM services that can help safeguard the uptime of data centers and IT equipment rooms. Various PM methodologies and approaches are discussed. Recommended practices are suggested.
WP-134 v2	Deploying High-Density Pods in a Low-Density Data Center Simple and rapid deployment of self-contained, high-density pods within an existing or new low-density data center is possible with today’s power and cooling technology. The independence of these high-density pods allow for predictable and reliable operation of high-density equipment without a negative impact on the performance of existing low-density power and cooling infrastructure. A side benefit is that these high-density pods operate at much higher electrical efficiency than conventional designs. Guidance on planning design, implementation, and predictable operation of high-density pods is provided.
WP-122 v1	Guidelines for Specification of Data Center Criticality / Tier Levels A framework for benchmarking a future data center’s operational performance is essential for effective planning and decision making. Currently available criticality or tier methods do not provide defensible specifications for validating data center performance. An appropriate specification for data center criticality should provide unambiguous defensible language for the design and installation of a data center. This paper analyzes and compares existing tier methods, describes how to choose a criticality level, and proposes a defensible data center criticality specification. Maintaining a data center’s criticality is also discussed.