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Energy Demands and Efficiency Strategies in Data Center Buildings

Description: Information technology (IT) is becoming increasingly pervasive throughout society as more data is digitally processed, stored, and transferred. The infrastructure that supports IT activity is growing accordingly, and data center energy demands haveincreased by nearly a factor of four over the past decade. Data centers house IT equipment and require significantly more energy to operate per unit floor area thanconventional buildings. The economic and environmental ramifications of continued data center growth motivate the need to explore energy-efficient methods to operate these buildings. A substantial portion of data center energy use is dedicated to removing the heat that is generated by the IT equipment. Using economizers to introduce large airflow rates of outside air during favorable weather could substantially reduce the energy consumption of data center cooling. Cooling buildings with economizers is an established energy saving measure, but in data centers this strategy is not widely used, partly owing to concerns that the large airflow rates would lead to increased indoor levels of airborne particles, which could damage IT equipment. The environmental conditions typical of data centers and the associated potential for equipment failure, however, are not well characterized. This barrier to economizer implementation illustrates the general relationship between energy use and indoor air quality in building design and operation. This dissertation investigates how building design and operation influence energy use and indoor air quality in data centers and provides strategies to improve both design goals simultaneously.As an initial step toward understanding data center air quality, measurements of particle concentrations were made at multiple operating northern California data centers. Ratios of measured particle concentrations in conventional data centers to the corresponding outside concentrations were significantly lower than those reported in the literature for office or residential buildings. Estimates using a material-balance model match well with empirical results, indicating that the dominant ...
Date: September 1, 2009
Creator: Shehabi, Arman
Partner: UNT Libraries Government Documents Department

Energy Implications of Economizer Use in California Data Centers

Description: In the US, data center operations currently account for about 61 billion kWh/y of electricity consumption, which is more than 1.5percent of total demand. Data center energy consumption is rising rapidly, having doubled in the last five years. A substantial portion of data-center energy use is dedicated to removing the heat generated by the computer equipment. Data-center cooling load might be met with substantially reduced energy consumption with the use of air-side economizers. This energy saving measure, however, has been shown to expose servers to an order-of-magnitude increase in indoor particle concentrations with an unquantified increase in the risk of equipment failure. An alternative energy saving option is the use of water-side economizers, which do not affect the indoor particle concentration but require additional mechanical equipment and tend to be less beneficial in high humidity areas. Published research has only presented qualitative benefits of economizer use, providing industry with inadequate information on which to base their design decisions. Energy savings depend on local climate and the specific building-design characteristics. In this paper, based on building energy models, we report energy savings for air-side and water-side economizer use in data centers in several climate zones in California. Results show that in terms of energy savings, air-side economizers consistently outperform water-side economizers, though the performance difference varies by location. Model results also show that conventional humidity restrictions must by relaxed or removed to gain the energy benefits of air-side economizers.
Date: August 1, 2008
Creator: Shehabi, Arman; Ganguly, Srirupa; Traber, Kim; Price, Hillary; Horvath, Arpad; Nazaroff, William W. et al.
Partner: UNT Libraries Government Documents Department

A characterization of the nonresidential fenestration market

Description: The purpose of this report is to characterize the nonresidential fenestration market in order to better understand market barriers to, and opportunities for, energy-efficient fenestration products. In particular, the goal is to: (1) Better understand how glazing products flow between industry groups. (2) Identify major decision makers directing the product flow. (3) Understand industry trends for certain technologies or products. (4) Characterize the role of energy codes and standards in influencing industry trends. (5) Assess the impact of product testing and certification programs on the industry. The U.S. glass industry is a $27 billion enterprise with both large producers and small firms playing pivotal roles in the industry. While most sectors of the glass industry have restructured and consolidated in the past 20 years, the industry still employs 150,000 workers. Nonresidential glazing accounts for approximately 18% of overall U.S. glass production. In 1999, nonresidential glazing was supplied to approximately 2.2 billion ft{sup 2} of new construction and additions. That same year, nonresidential glazing was also supplied to approximately 1.1 billion ft{sup 2} of remodeling construction. With an industry this large and complex, it is to be expected that many market participants can influence fenestration selection. If market barriers to the selection of high performance fenestration products are better understood, then the U. S. Department of Energy (USDOE), the Northwest Energy Efficiency Alliance (NEEA), and others can develop programs and policies that promote greater energy efficiency in commercial glazing products.
Date: July 25, 2002
Creator: Shehabi, Arman; Eley, Charles; Arasteh, Dariush & Degens, Phil
Partner: UNT Libraries Government Documents Department

Can combining economizers with improved filtration save energy and protect equipment in data centers?

Description: Economizer use in data centers is an energy efficiency strategy that could significantly limit electricity demand in this rapidly growing economic sector. Widespread economizer implementation, however, has been hindered by potential equipment reliability concerns associated with exposing information technology equipment to particulate matter of outdoor origin. This study explores the feasibility of using economizers in data centers to save energy while controlling particle concentrations with high-quality air filtration. Physical and chemical properties of indoor and outdoor particles were analyzed at an operating northern California data center equipped with an economizer under varying levels of air filtration efficiency. Results show that when improved filtration is used in combination with an economizer, the indoor/outdoor concentration ratios for most measured particle types were similar to levels when using conventional filtration without economizers. An energy analysis of the data center reveals that, even during the summer months, chiller savings from economizer use greatly outweigh any increase in fan power associated with improved filtration. These findings indicate that economizer use combined with improved filtration could reduce data center energy demand while providing a level of protection from particles of outdoor origin similar to that observed with conventional design.
Date: June 5, 2009
Creator: Shehabi, Arman; Ganguly, Srirupa; Gundel, Lara A.; Horvath, Arpad; Kirchstetter, Thomas W.; Lunden, Melissa M. et al.
Partner: UNT Libraries Government Documents Department

Report to Congress on Server and Data Center Energy Efficiency: Public Law 109-431

Description: This report was prepared in response to the request from Congress stated in Public Law 109-431 (H.R. 5646),"An Act to Study and Promote the Use of Energy Efficient Computer Servers in the United States." This report assesses current trends in energy use and energy costs of data centers and servers in the U.S. (especially Federal government facilities) and outlines existing and emerging opportunities for improved energy efficiency. It also makes recommendations for pursuing these energy-efficiency opportunities broadly across the country through the use of information and incentive-based programs.
Date: August 2, 2007
Creator: Energy, Alliance to Save; Incorporated, ICF; Incorporated, ERG; Agency, U.S. Environmental Protection; Brown, Richard E; Brown, Richard et al.
Partner: UNT Libraries Government Documents Department

Report to Congress on Server and Data Center Energy Efficiency: Public Law 109-431: Appendices

Description: This report is the appendices to a companion report, prepared in response to the request from Congress stated in Public Law 109-431 (H.R. 5646),"An Act to Study and Promote the Use of Energy Efficient Computer Servers in the United States." This report assesses current trends in energy use and energy costs of data centers and servers in the U.S. (especially Federal government facilities) and outlines existing and emerging opportunities for improved energy efficiency. It also makes recommendations for pursuing these energy-efficiency opportunities broadly across the country through the use of information and incentive-based programs.
Date: August 2, 2007
Creator: Energy, Alliance to Save; Incorporated, ICF; Incorporated, ERG; Agency, U.S. Environmental Protection; Brown, Richard E; Brown, Richard et al.
Partner: UNT Libraries Government Documents Department