Download or read book Experimental Study on Effects of Segregated Cooling Provisioning on Thermal Performance of Information Technology Servers in Air Cooled Data Centers written by Ashwin Venugopal Siddarth and published by . This book was released on 2016 with total page 43 pages. Available in PDF, EPUB and Kindle. Book excerpt: Modern Information Technology (IT) equipment are typically assumed to operate in quiescent airflow conditions in an uncontained data center facility. In this study, the multi-scaled thermal management strategies are reconsidered at the IT chassis and rack level for a containment system. For an ideal containment configuration of airflow provisioning the entirety of conditioned air provided by the Computer Room Air Conditioning (CRAC) unit would flow through the IT equipment and return back to the CRAC. But in actuality a lack of interfaced airflow distribution exists between the amount of conditioned air provisioned to the rack and the volume capacity ingested by the IT equipment thereby decreasing the efficiency of the overall cooling system. This work evaluates the thermal performance of IT servers when operating in a representative cold aisle containment system. In this study, the impact of positive and negative static pressure differentials between the inlet and exhaust of a representative rack is experimentally studied. The effect of fan proximity in the chassis layout to variations in pressure differentials is assessed. This information can be helpful in optimizing the desired static pressure set points within the room and define coupled internal fan control strategies to achieve the most energy efficient use of cooling resources.

Download or read book Experimental and Computational Study of Multi level Cooling Systems at Elevated Coolant Temperatures in Data Centers written by Manasa Sahini and published by . This book was released on 2017 with total page 111 pages. Available in PDF, EPUB and Kindle. Book excerpt: Data centers house a variety of compute, storage, network IT hardware where equipment reliability is of utmost importance. Heat generated by the IT equipment can substantially reduce its service life if Tj,max, maximum temperature that the microelectronic device tolerates to guarantee reliable operation, is exceeded. Hence, data center rooms are bound to maintain continuous conditioning of the cooling medium. This approach often results in over-provisioned cooling systems. In 2014, U.S. Data center electricity consumption is about 1.8% of the total electrical energy in the country. Hence, data center power and cooling have become significant issues facing the IT industry. The first part of the study focuses on air cooling of electronic equipment at room level. Data centers are predominantly cooled by perimeter computer air handling units that supply cold air to the raised floor plenum and the cold air helps in removing the heat generated by IT equipment. This method tends to be inadequate especially when the average power density per rack rises above 4 kW. As a solution to mitigate this problem, different rack and row based cooling solutions have been proposed and used. The primary focus of these cooling methods is to bring cooling closer to the heat source which is the IT rack thereby improving the heat dissipation process along with controlled air flow management in the data center room. Mostly known close-coupled cooling solutions include rear-door heat exchanger, in-row coolers, and over-head cooling. In this study, a new end-of-aisle close-coupled cooling solution for small data center cooling room has been proposed. As oppose to the existing designs, this design is distinctive in eliminating the risk of placing the liquid on top of IT racks along with achieving cooling energy efficiency. Three different configurations of the proposed designs are studied for its thermal performance using computational modeling. The second part of the study focuses on liquid cooling at rack level. Liquid cooling addresses the critical issues related to typical air cooling in servers because of its better heat transfer characteristics. Water-cooling at the device level can be an efficient solution since water has higher thermal capacitance when compared to traditional heat carrying medium i.e., air. The emerging practice in the data center industry is to maximize the use of economizer usage by reducing/eliminating the usage of chiller while taking advantage of outside ambient conditions to cool the data centers. Liquid cooled racks are generally designed with different configuration of pumping systems. Empirical study is conducted on a state-of-art liquid cooled electronic rack for high coolant inlet, commonly known as warm-water cooling in order to evaluate the cooling performance of distributed vs. centralized coolant pumping systems. Experimental set up is instrumented such that detailed analysis is employed to study component temperatures as well as cooling performance of the rack at elevated inlet conditions. The third part of the study focuses on the impact of high server inlet temperatures to static power at server level. In order to maximize the use of economizers, the IT hardware will be exposed to higher inlet temperatures which would lead to higher operating temperatures of the processors. The operating temperature of the CPU has direct influence on the static power due to subthreshold leakage which is known to reduce the performance of the processor. The current work serves as a firsthand investigation to study trade-off between IT performance and energy efficiency for elevated inlet temperature in air vs. liquid cooled servers. Air cooled IT along with the liquid cooled counter-parts are instrumented and extensively tested to simulate the high ambient conditions at the test bed data center.

Download or read book Optimum Cooling of Data Centers written by Jun Dai and published by Springer Science & Business Media. This book was released on 2013-11-20 with total page 196 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book describes the use of free air cooling to improve the efficiency of, and cooling of, equipment for use in telecom infrastructures. Discussed at length is the cooling of communication installation rooms such as data centers or base stations, and this is intended as a valuable tool for the people designing and manufacturing key parts of communication networks. This book provides an introduction to current cooling methods used for energy reduction, and also compares present cooling methods in use in the field. The qualification methods and standard reliability assessments are reviewed, and their inability to assess the risks of free air cooling is discussed. The method of identifying the risks associated with free air cooling on equipment performance and reliability is introduced. A novel method of assessment for free air cooling is also proposed that utilizes prognostics and health management (PHM). This book also: Describes how the implementation of free air cooling can save energy for cooling within the telecommunications infrastructure. Analyzes the potential risks and failures of mechanisms possible in the implementation of free air cooling, which benefits manufacturers and equipment designers. Presents prognostics-based assessments to identify and mitigate the risks of telecommunications equipment under free air cooling conditions, which can provide the early warning of equipment failures at operation stage without disturbing the data centers' service. Optimum Cooling for Data Centers is an ideal book for researchers and engineers interested in designing and manufacturing equipment for use in telecom infrastructures.

Download or read book Thermo mechanical Design Considerations at the Server and Rack Level to Achieve Maximum Data Center Energy Efficiency written by Richard Mark Eiland and published by . This book was released on 2017 with total page 107 pages. Available in PDF, EPUB and Kindle. Book excerpt: Continually increasing demand for information technology (IT) applications and services has provided sustained growth and interest in data centers. The large amounts of energy consumed by data center facilities have placed a significant emphasis on the energy efficiency of their overall operation. One area of particular importance is the cooling energy required. Heat generation within a data center starts at the server level, specifically within the microelectronic devices that process digital information. Convective heat transfer is the primary driver for the removal of heat from an individual server. As such, cooling efficiency at the server level will be dictated by the pumping power required to move a cooling fluid through the system. Many methods are available for removing heat from the server, either with air or liquids as the cooling medium. This work evaluates new, efficient approaches for removing that heat and the pertinent design considerations that must be taken into account for successful implementation. In general, smaller fans operate at lower efficiencies than larger fans of proportional linear dimensions. The applicability of replacing smaller, 60mm fans from within the chassis of web servers with an array of either 80mm or 120mm fans consolidated to the back of a rack is experimentally tested. Initial characterization of the selected fans showed the larger 80mm and 120mm fans operate at double peak total efficiency of the smaller 60mm fans. A stack of four servers was used in a laboratory setting to represent a rack of servers. When all four servers were stressed at uniform computational loadings, the 80mm fan array resulted in between 50.1% to 52.6% reduction in total rack fan power compared to the baseline 60mm fans. The 120mm fan array showed similar reduction in rack fan power of 47.6% to 54.0% over the baseline 60mm fan configuration. Since actual data centers rarely operate at uniform computational loading across servers in a rack, a worst case scenario test was conceived. In this test, the arrays of larger fans were controlled by a single server operating at peak computational workload while the other three in the rack remained idle. Despite significant overcooling in the three idle servers, the 80mm and 120mm fan configurations still showed 35.3% and 33.8% reduction in total rack fan power compared to the best possible operation of the 60mm fans. The findings in this study strongly suggest that a rack-level fan scheme in which servers share airflow is more efficient alternative to fans contained within the server. Air flow management is a critical tool to maintain efficient operation of a data center cooling scheme. Provisioning of airflow from CRAC units and containment systems often lead to changes in the static pressure at the inlet to server racks. Through experimental testing on an Air Flow Bench it is observer that static pressure at the inlet to servers has a significant influence on the thermal performance and fan cooling energy consumption within the server itself. Reduction in server fan power or component temperatures can be achieved by increasing the static pressure at the server inlet. Complementary design and control at the room level with this information at the server level can lead to reduction in overall system fan power and more energy efficient data center operation. Complete immersion of servers in dielectric mineral oil has recently become a promising technique for minimizing cooling energy consumption in data centers. However, a lack of sufficient published data and long term documentation of oil immersion cooling performance makes most data center operators hesitant to apply these approaches to their mission critical facilities. In this study, a single server was fully submerged horizontally in mineral oil. Experiments were conducted to observe the effects of varying the volumetric flow rate and oil inlet temperature on the thermal performance and power consumption of the server. Specifically, temperature measurements of the CPUs, motherboard components, and bulk fluid were recorded at steady state conditions. These results provide an initial bounding envelope of environmental conditions suitable for an oil immersion data center. Comparing the results from baseline tests performed with traditional air cooing, the technology shows a 34.4% reduction in the thermal resistance of the system. The cooling loop was able to achieve partial power usage effectiveness (pPUECooling) values as low as 1.03. This server-level study provides a preview of possible facility energy savings by utilizing high temperature, low flow rate oil for cooling. Following this, visual observations, microscopic measurements, and testing of mechanical properties were taken. Evaluation of the technology's impact on the mechanical reliability of components and operability of data centers is made.

Download or read book Experimental Analysis for Optimization of Thermal Performance of a Server in Single Phase Immersion Cooling written by Pravin Ashok Shinde and published by . This book was released on 2019 with total page 57 pages. Available in PDF, EPUB and Kindle. Book excerpt: Liquid immersion cooling of servers in synthetic dielectric fluids is an emerging technology which offers significant cooling energy saving and increased power densities for data centers. A noteworthy advantage of using immersion cooling is high heat dissipation capacity which is roughly 1200 times greater than air. Other advantages of dielectric fluid immersion cooling include high rack density, better server performance, even temperature profile, reduction in noise. The enhanced thermal properties of oil lead to the considerable saving of both upfront and operating cost over traditional methods. In this study, a server is completely submerged in a synthetic dielectric fluid. Experiments were conducted to observe the effects of varying the volumetric flow rate and oil inlet temperature on thermal performance and power consumption of the server. Various parameters like total server power consumption, the temperature of all heat generating components like Central Processing Unit (CPU), Dual in Line Memory Module (DIMM), input/output hub (IOH) chip, Platform Controller Hub (PCH), Network Interface Controller (NIC) will be measured at steady state. Since this is an air-cooled server, the results obtained from the experiments will help in proposing better heat removal strategies like heat sink optimization, better ducting and server architecture. Assessment will also be made on the effect of thermal shadowing caused by the two CPUs on the nearby componentslike DIMMs and PCH.

Download or read book Rack Level Study of Hybrid Cooled Servers Using Warm Water Cooling with Variable Pumping for Centralized Coolant System written by Chinmay Sanjay Kshirsagar and published by . This book was released on 2019 with total page 53 pages. Available in PDF, EPUB and Kindle. Book excerpt: As the worldwide demand for the data centers grows, so does the size and load placed on data centers which leads to the applied constraints on power and space available to the operator. Cooling power consumption is a major contributor of the total energy consumption of the system. In the process of optimization of cooling energy consumption per performance unit, liquid cooling technology has emerged as one of the most viable solutions. In this rack level study, 2OU (Open U) hybrid cooled web servers are tested for an evaluation of warm water cooling in centralized coolant system. Effects of higher inlet temperatures of the coolant in terms of device temperatures as well as IT and cooling power have been observed as a part of the evaluation. The study discusses the significance of variable pumping in centralized coolant system for its more efficient use. The experimental setup for cooling consists of 1/3rd sized mini rack capable of housing up to eleven liquid cooled web servers and two heat exchangers. The cooling configuration is centralized and has two redundant pumps placed in series with heat exchanger at the rack. CPUs of each server are liquid cooled with using passive micro channel cold plates while rests of the components are air cooled. Synthetic load has been generated on each servers for thermal stress testing and observed performance characteristics such as device temperatures and cooling power consumption of servers. Centralized redundant pumps are separately powered using an external DC power supply unit. The pump speed is varied with variable voltage supply ranging from 11V to 17V across the armature. The experimental testing is carried out at higher inlet temperatures ranging from 25°C to 45°C which falls within the ASHRAE liquid cooled envelope W4.Variable pumping at higher inlet temperatures has been achieved to evaluate to operating temperatures of device components for reliability and reduction in operational cooling power consumption of the servers.

Download or read book Cooling Efficiency Improvement of a Data Center Using Optimized Cabinet Design and Hybrid Cooling with High Inlet Conditions of Single phase Coolant and Air written by Uschas Chowdhury and published by . This book was released on 2021 with total page 120 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objective of this study is to improve and optimize the cooling efficiency of liquid and air cooling from server to room level while applying best practices in the industry. The effect of increased air and coolant temperature has been explored through a literature survey and studies are conducted from device level to room level for air and liquid cooling. Three major aspects are considered. A closed-form air cooling solution is proposed for high-powered racks in a modular data center equipped with in-row coolers. Direct-to-chip liquid cooling technology is extensively studied at the server level for raised air and coolant inlet temperature for determining thermal performance and reliability of IT equipment. A cost analysis for liquid cooling has been conducted with a TCO model for the performance improvement and holistic evaluation of a data center with air and liquid cooling.The first part consists of a room-level numerical study conducted with high powered racks in a modular data center with regular low-powered racks. Typical modular data centers are cooled by perimeter or outdoor cooling units. A comparative analysis is performed for a typical small-sized non-raised facility to investigate the efficacy and limitations of in-row coolers in thermal management of IT equipment with variation in rack heat load and containment. Several other aspects like a parametric study of variable opening areas of duct between racks and in-row coolers, the variation of operating flow rate, and failure scenarios are also studied to find proper flow distribution, uniformity of outlet temperature, and predict better performance, energy savings and reliability. The results are presented for general guidance for flexible and quick installation and safe operation of in-row coolers to improve thermal efficiency. The Second Part consists of a server-level numerical and experimental study with raised inlet air and coolant temperature for a hybrid cooled server. A detailed numerical study of an enterprise 1U hybrid cooled server is performed to predict the effect of raised inlet air temperature on the component temperatures following the limits of ASHARE air cooling classes. Then, an experimental study is performed in an environmental chamber with high inlet air temperatures. Results for both studies are compared. Previously warm water cooling or increased coolant inlet temperature has been experimentally tested on the respective server. Thus, the effect of both air and liquid coolant temperature has been presented and scaled up to a data center level with help of industry-standard tools for 1D flow network analysis to address the cooling efficiency improvement. The third part consists of a cost analysis of a data center with air and liquid cooling using an established TCO model. The ASHRAE cooling classes for air and liquid cooling are used based on the experimental findings. Also, the effect of cooling efficiency improvements at component and server level and increased inlet conditions are used to compare with a baseline model with air cooling.

Download or read book Experimental Characterization of Hybrid Cooled Cisco Servers Including the Effect of Warm Water Cooling written by Md Malekkul Islam and published by . This book was released on 2016 with total page 37 pages. Available in PDF, EPUB and Kindle. Book excerpt: The information technology (IT) owners are experiencing a greater cooling challenge because of the increase in power density due to modern computational needs. The non-uniform power density in each server is forcing the industry to use hybrid cooling technology. Server components of different cooling requirement needs air water hybrid cooling which offers variable design alternatives. Such hybrid cooling technology cools the high heat generating components by using water or water based fluid, whereas, the rest of the components are cooled by air using internal fans. Conventional air cooling is more than sufficient for the components with less thermal demand. Air cooling is cheap, highly available and it has better serviceability than any other cooling methods. The objective is to optimize the cooling power of the air cooling loop of such hybrid cooled server. As the major components are cooled by the water based fluid, the other components generate less heat which can be cooled by much less volume of air then supplied in air cooled server. The volume of air supplied is controlled by varying the air flow rate through the internal fans. Also number of fan was reduced to 3 instead of 5 to minimize the power consumption. Parameters like CPU and memory utilization are varied with the flow rate. ASHRAE recommends that the most data centers can be maintained between 20 and 25°C, with an allowable range of 15 to 32°C. But for this type of hybrid cooling servers, the processor is cooled by water. So the servers can operate at much higher inlet air temperature. In this paper the hybrid cooled servers will be characterized also. The server used for experimental testing has processor with 135 watt thermal design power. Also, the server utilizes distributed pumping i.e. each cold plate has its own pump. The test matrixes consider supply and return water temperatures, flow rate of coolant for optimizing the cooling power consumption. The supply inlet water temperature was varied by LabView code. Further, processor and outlet temperature was monitored for better understanding the case scenario. The relation between supply water temperature and different power utilization gives the data for modeling different cooling infrastructure. This in turn, will give an idea of power savings by utilizing such energy efficient hybrid solution for cooling servers in a datacenter.

Download or read book Experimental Analysis of a Single phase Direct Liquid Cooled Server Performance at Extremely Low Temperatures for Extended Time Periods written by Gautam Gupta (M.S.) and published by . This book was released on 2019 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt: A data center is a centralized facility that we use for housing the computer systems and its related components such as high-end servers, redundant data connection and security controls. The next radical change in the thermal management of data centers is to shift from conventional cooling methods like air-cooling to direct liquid cooling (DLC) to deal with high thermal mass. The past few years have consistently seen wider adoption of direct liquid cooling because of its simplicity and high heat dissipation capacity. Passive single phase engineered fluid immersion cooling has several other benefits like better server performance, even temperature profile and higher rack densities.This report provides an overview of the considerations of using single-phase dielectric fluid to cool a server based on experiments conducted at extreme conditions in an environmental chamber. The server was placed in the environmental chamber ranging from extremely low temperatures at -20°C to 20°C and varying humidity for extended durations. Thermal overstress experiment was performed on a fully immersed server and its cooling system components. This work explores the effects of low temperature on the performance of a server and other components like pump including flow rate drop and starting trouble under extreme climatic conditions. The possibility of connector seals observing reduced performance upon accelerated temperature cycling is addressed. Throttling limit for the CPU along with power draw over a range of different temperatures was recorded. Similar observations were recorded for pump. Dependence of pump performance on operating temperature determines the flow rate and operating temperature relationship. Pumping power consumption is directly related to the operating cost of a data center.This research can be expanded by performing similar experiments at elevated temperatures to establish an operating temperature envelope in order to get the optimum performance of a direct liquid cooled high-density server.

Download or read book Energy Analysis of Novel Data Center Cooling Technology written by Babak Lajevardi and published by . This book was released on 2015 with total page 94 pages. Available in PDF, EPUB and Kindle. Book excerpt: Worldwide, many organizations are pursuing higher energy efficiency by reducing power consumption of their processes, systems, and supporting infrastructure. The rapid growth of the information technology (IT) industry and the miniaturization of semiconductors have resulted in substantial increases in energy consumption and power density of IT equipment, and, subsequently, heat generated by data center equipment contained within data center racks. Energy efficiency and thermal management effectiveness are two major issues facing data centers due to increases in heat dissipated from data center racks. Higher data center energy efficiency will lower total cost of ownership (TCO) and enable organizations to better manage increasing computing and network demands. To improve data center energy efficiency, efforts have been focused on novel center-level and rack-level cooling technologies to remove the heat generated by high-density servers. The research presented herein investigates the operational energy performance of a data center evaporative cooling system and the manufacturing energy requirements for a server-scale microchannel heat exchanger (MCHX). Energy monitoring and analysis was conducted to evaluate an evaporative cooling system installed at a data center located in Gresham, OR. A holistic metric and measurement approach is developed to evaluate the impact of changes for data center infrastructure and information technology (IT) equipment. It was found that the developed metric is more responsive to changes in cooling power and environmental conditions than commonly used metrics. Further, the evaporative cooling technology was shown to be more efficient and effective than conventional cooling technology. Liquid cooling has been demonstrated as an effective strategy to provide a reliable environment for servers and to reduce the load on conventional cooling systems. While microchannel process technology (MPT)-based devices offer a space-efficient approach to liquid cooling of high-density servers, MPT device manufacturing, in particular device patterning and bonding, has been shown to be energy intensive. A weld depth model for bonding of MPT devices is developed and used to understand the capabilities and limitations of the laser welding process. Energy analysis is conducted for the production of a MCHX device to liquid cool the warm exiting air from server racks. Analysis of the patterning, photochemical machining (PCM), and bonding, diffusion bonding and laser welding, processes revealed a considerable reduction in cumulative energy demand (CED) and global warming potential (GWP) when laser welding is used in place of diffusion bonding. This environmental impact reduction was due to reduced process time, reduced energy use, and improved process yield.

Download or read book Improving Ducting to Increase Cooling Performance of High end Web Servers Subjected to Significant Thermal Shadowing written by Divya Mani and published by . This book was released on 2015 with total page 54 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ensuring that all the critical components like CPU's receive sufficient amount of flow as per their requirement is an vital importance in implementing air cooling for IT equipments. In addition to that the overall system resistance varies with the component location within the chassis. In this study, parametric improvement in chassis ducting system is made to counteract the effects of thermal shadowing in a open compute air cooled server in which a CPU thermally shadows the other. Commercially available computational fluid dynamics codes have permitted simulation of server models to predict efficiency of the servers with every changes made in the design and input variables. Initially this study discusses about the methodology that outlines experimental procedures and tests employed for generating data for calibration of a detailed server model generated using a commercially available CFD tool. The resulting experimentally-calibrated computational fluid dynamics model of the server is used to parametrize and improve the duct design and the location with the view of estimating the effect of airflow bypass on fan power consumption and CPU die temperatures. Improvements achieved are experimentally tested by prototyping the improved chassis using acrylic sheets and reported with reduced flow rates, flow speeds, fan power consumption and fan acoustic noise levels. Further, the study is extrapolated for evaluating the savings in total pumping power and flow rates in the layout of a traditional data center and highly-efficient data center working on air side economization. Savings in amount of water consumed by the layout and savings in number of computer room air conditioning(CRAC) units are also evaluated.

Download or read book Cooling and Heat Recovery of Data Centers written by Ahmad Alamir Sbaity and published by . This book was released on 2022 with total page 159 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objective of this study is to investigate passive and hybrid cooling, by performing heat recovery within a typical data center. The chosen cooling method is the thermosyphon loop, as it allows the transfer of high powers over a long distance. The chosen evaporator is a microchannel heat exchanger, the condenser is formed by finned tubes. An experimental parametric study is made by varying the fill ratio, the thermal power of the servers and the outside temperature of the air ensuring the cooling by natural convection. A second experimental study is done by cooling the condenser with water in forced convection. An annual numerical study on data centers in several cities in France is done to quantify the energy savings achieved with passive and hybrid cooling. The pPUE (partial power use efficiency) coefficient is calculated to evaluate the efficiency of the proposed cooling system. Finally, the thermosyphon loop is combined with a heat pump in order to recover heat from the data centers and distribute it. The energy savings of the proposed system are compared to the use of a boiler to heat a house. An economic study is made to calculate the payback period in several climates. The ERE (energy reuse efficiency) coefficient is also calculated to evaluate the capacity of the heat recovery system.

Download or read book Performance Evaluation for a Modular Scalable Passive Cooling System in Data Centers written by and published by . This book was released on 2009 with total page 15 pages. Available in PDF, EPUB and Kindle. Book excerpt: Scientific and enterprise data centers, IT equipment product development, and research data center laboratories typically require continuous cooling to control inlet air temperatures within recommended operating levels for the IT equipment. The consolidation and higher density aggregation of slim computing, storage and networking hardware has resulted in higher power density than what the raised-floor system design, coupled with commonly used computer rack air conditioning (CRAC) units, was originally conceived to handle. Many existing data centers and newly constructed data centers adopt CRAC units, which inherently handle heat transfer within data centers via air as the heat transfer media. This results in energy performance of the ventilation and cooling systems being less than optimal. Understanding the current trends toward higher power density in IT computing, more and more IT equipment manufacturers are designing their equipment to operate in 'conventional' data center environments, while considering provisions of alternative cooling solutions to either their equipment or supplemental cooling in rack or row systems. In the meanwhile, the trend toward higher power density resulting from current and future generations of servers has created significant opportunities for precision cooling to engineer and manufacture packaged modular and scalable systems. The modular and scalable cooling systems aim at significantly improving efficiency while addressing the thermal challenges, improving reliability, and allowing for future needs and growth. Such pre-engineered and manufactured systems may be a significant improvement over current design; however, without an energy efficiency focus, their applications could also lead to even lower energy efficiencies in the overall data center infrastructure. The overall goal of the project supported by California Energy Commission was to characterize four commercially available, modular cooling systems installed in a data center. Such modular cooling systems are all scalable localized units, and will be evaluated in terms of their operating energy efficiency in a real data center, respectively, as compared to the energy efficiency of traditional legacy data center cooling systems. The technical objective of this project was to evaluate the energy performance of one of the four commercially available modular cooling systems installed in a data center in Sun Microsystems, Inc. This report is the result of a test plan that was developed with the industrial participants input, including specific design and operating characteristics of the selected passive, modular localized cooling solution provided by vendor 4. The technical evaluation included monitoring and measurement of selected parameters, and establishing and calculating energy efficiency metrics for the selected cooling product, which is a passive, modular, scalable liquid cooling system in this study. The scope is to quantify energy performance of the modular cooling unit corresponding to various server loads and inlet air temperatures, under various chilled-water supply temperatures. The information generated from this testing when combined with documented energy efficiency of the host data center's central chilled water cooling plant can be used to estimate potential energy savings from implementing modular cooling compared to conventional cooling in data centers.

Download or read book Impact of Louver Orientation on Air Flow Distribution and Thermal Management of Data Centers written by Kushal A. Aurangabadkar and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Nowadays with the increasing use of technology, Traditional data centers are being replaced by the highly efficient Containerized or Modular Data centers. The cooling systems and constructional cost employed for Traditional Data centers is more and inefficient. The research intricate, about 23% of the power is consumed by HVAC cooling units and which in turn leads to increase in operational costs. Hence in order to reduce the operational costs, free cooling with Air side economizer is incorporated, compared to other cooling systems. Airflow Distribution plays an important role in the Thermal management, if the airflow is less in quantity it may lead to unpredictable thermal performance, while too much airflow may cause the server fans to blow-off or damage to the servers. Numerous research and study has been done on the use of louvers as shading devices for residential purposes but the study on Impact of the louver orientation on Air Flow Distribution and Thermal Management is limited. The amount of airflow allowed to pass through louvered window is function of its face velocity. The Air-Flow pattern through the louvered window is determined by the louver orientation. These two factors directed us to do a study on the Impact of the Louvers orientation on the Air Flow Distribution and Thermal Management of Data center. The first half of the thesis will discuss design and modeling of IT equipment's including Power cooling module, Air Plenum, Data centers using commercially available CFD software. It would also segregate there Heat load specifications along with a brief overview of Free Cooling and importance of louvers. The CFD modeling and analysis will include the advantages of using a compact model instead of the detailed model. The second part will discuss effects on the thermal performance and Air Flow Distribution for 0, 15,25,35,45 Degree Louver angle cases. However on comparing the simulation results for different angle cases, we find with the increase in the Louver angle, re-circulations are incurred which in turn affects the Thermal management inside the IT equipment's. The system is optimized comparing different louver angles. The study was done in collaboration with an industrial partner and such of the results have been adopted in various cooling systems.

Download or read book Thermal Characterization of an Isolated Hybrid Cooled Server with Pump and Fan Failure Scenarios written by Uschas Chowdhury and published by . This book was released on 2019 with total page 31 pages. Available in PDF, EPUB and Kindle. Book excerpt: Modern day data centers are operated at high power for increased power density, maintenance, and cooling which covers almost 2 percent (70 billion kilowatt-hours) of the total energy consumption in the US. IT components and cooling system occupy the major portion of this energy consumption. Although data centers are designed to perform efficiently, cooling the high-density components is still a challenge. So, alternative methods to improve the cooling efficiency has become the drive to reduce the cooling cost. As liquid cooling is more efficient for high specific heat capacity, density, and thermal conductivity, hybrid cooling can offer the advantage of liquid cooling of high heat generating components in the traditional air-cooled servers. In this experiment, a 1U server is equipped with cold plate to cool the CPUs while the rest of the components are cooled by fans. In this study, predictive fan and pump failure analysis are performed which also helps to explore the options for redundancy and to reduce the cooling cost by improving cooling efficiency. The ASHRAE guidance class W4 for liquid cooling is chosen for experiment to operate in a range from 25°C - 45°C. The experiments are conducted separately for the pump and fan failure scenarios. Computational loads are applied while powering only one pump and the miniature dry cooler fans are controlled externally to maintain constant inlet temperature of the coolant. As the rest of components such as DIMMs & PCH are cooled by air,maximum utilization for memory is applied while reducing the number fans in each case for fan failure scenario. The components temperatures and power consumption are recorded in each case for performance analysis.

Download or read book Maximizing Use of Air side Economization Direct and Indirect Evaporative Cooling for Energy Efficient Data Centers written by Betsegaw Kebede Gebrehiwot and published by . This book was released on 2016 with total page 113 pages. Available in PDF, EPUB and Kindle. Book excerpt: Data centers house information technology (IT) equipment such as servers and network switches which are vital for our networked modern society by providing digital data storage, data processing and connectivity. Data centers house few hundreds to tens of thousands of IT equipment that consume few kilowatt-hours to multi-megawatt-hours of electrical energy that gets dissipated as heat. IT equipment need to be properly cooled so that they operate reliably for their expected lifetime. For air cooled IT equipment, manufacturers provide heat sinks, cold plates, fans, et cetera to remove heat from the vicinity of heat dissipating components and data centers need to continuously supply cold air to the IT equipment and remove hot from the vicinity of the IT equipment. Type of cooling system used in a data center is an important factor in the overall efficiency and reliability of the data center. This dissertation focuses on use of air-side economization (ASE), direct evaporative cooling (DEC), indirect evaporative cooling (IEC), and indirect/direct evaporative cooling (I/DEC) as a way to reduce cooling cost of data centers. A test bed modular data center, which has a cooling unit that operates in ASE or two-stage I/DEC modes, and located in Dallas, TX, is primarily used for this study. Included in the study are analysis of weather data to determine what percentage of a year these cooling systems can be used, modeling of the test bed modular data center using computational fluid dynamics (CFD) tool, discussion on improvements that can be made to the cooling system and factors that limit use of ASE and I/DEC, method for improving the DEC control system, et cetera. In addition, CFD modeling of another modular data center is used to show importance of proper airflow management within cold aisle of data centers and impact of hot aisle pressurization on operating point of server fans.

Download or read book Thermal Destratification of Air Streams to Improve the Cooling Provisioning of Air cooled Data Centers written by Anto Joseph Barigala Charles Paulraj and published by . This book was released on 2021 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt: Air side economization is an arrangement of duct, damper and automatic control system which together allow introducing outside air to reduce the mechanical cooling during mild or cold weather thereby decrease the energy consumption. The outside ambient air and heated return air from the information technology (IT) pod is mixed inside a dedicated space to achieve a target cold aisle operating temperature and thereby increase economization. Major constrain faced by the design engineers while designing the Mixing Chamber/ Plenum is the stratification of air stream due to the Temperature gradient in the mixed air stream and this stratification can be attributed to the short span of time and space that is available for the air streams to interact with each other. Thermal stratification can lead to coil freeze-ups, nuisance freeze-stat trips, energy wastage due to sensing error and poor indoor air quality and increases the cooling power. So, to achieve our objective we want to understand the fundamental physical phenomenon which causes mixing of any two fluids and thereby apply the knowledge to our test scenario. Literature review gave us the information about Richardson number a dimensionless number which is a ratio between buoyancy and flow shear stress and for improving the process of mixing the Richardson number should be minimized. The variables involved in minimizing the Richardson number are the velocity and temperature difference between the two fluid and the total vertical column height of the two fluid that needs to be mixed. This fundamental understanding will help us in determining the structural features needs to be achieve the desired mixing. The scope of the project is also extended to address the effect of thermal stratification after evaporative media cooling pad, in this scenario the process of segmentation of the pad for reducing the relative humidity also creates thermal stratification. Computational Fluid Dynamic analysis is carried out to report the proof of concept and thereby report the changes in the effectiveness of the mixing process at upstream of heating coil and downstream of cooling pad.