The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
Water-cooled server racks are typically closed cabinets, so no heat load is removed by the room cooling system in a raised floor data center. Instead, the cooling is provided by a closed system employing an air-water (fin-tube) heat exchanger. This kind of heat exchanger uses chilled water from a central plant, and there is the potential of using the waste heat that is returned. The goal of this study...
To meet the high cooling demand in the electronics industry, enhanced microchannel heat sinks were introduced. However, the intricacies and high costs associated with microfabrication technologies prove them unsuitable for application in conventional heat exchangers. Hence, the motivation to implement microscale passages in macro geometries ensues. In this study, the annular microchannel is formed...
In this effort, theoretical modeling was employed to understand the impact of bypass on the flow performance of air cooled heat sinks. Fundamental mass and flow energy conservation equations across a longitudinal fin heat sink and the bypass regions were applied and a generic parameter, referred as the Flow Bypass Factor, was identified from the theoretical solution that mathematically captures the...
This paper evaluates the impact of pressure drop in server racks on the cooling of the IT equipment. The measured impedance curves for servers internal resistance, rack doors, and Cable Management Arms (CMA) are used to estimate the reduction in the cooling airflow rate. In this study, 1 RU and 2 RU servers, and a 9 RU server simulator are used as representative IT equipment. A Computational Fluid...
Concerted efforts are being made by data center professionals to ensure that data centers are made more sustainable by reducing energy consumption. The combination of increasing IT workloads and packaging densities place stringent requirements on data center cooling systems. Various traditional airflow management technologies have been implemented that propose significant energy savings as well as...
Data centers consume a significant amount of energy in the US and worldwide, much of which is consumed by the cooling infrastructure, particularly the chiller plant and computer room air conditioners and air handlers. To enable energy efficient data center designs, ASHRAE added two new IT environmental classes, A3 and A4, with associated allowable inlet air temperatures of 40C and 45C respectively...
Air-cooled Data Centers absorb heat in central room air conditioners or air handlers and most commonly reject the heat through cooling towers to ambient air. The energy efficiency of the overall cooling system is determined by the energy efficiency of its components, its thermodynamic design and layout, and the protocol for its control, operation and its operational set points. The current work is...
A model for a basic hot aisle/cold aisle data center configuration was built and analyzed using the commercial computational fluid dynamics (CFD) software FloTHERM. The CFD study was motivated by experimental data that sho wed air recirculatio n from the hot aisle to the cold aisle through the gap between the floor and the bottom of the server cabinet. This flow can be attributed to lower values of...
This is an effort to use natural convection inside a room to enhance the heat flow from a ceiling-mounted recessed LED fixture. Thermal performance of recessed fixtures is evaluated experimentally in a wooden box specified by Underwriters Laboratories, called a UL box. The UL box is approximately 0.67 × 0.62 × 0.46 m and is used to emulate an insulated ceiling for testing purposes. The UL box is suspended...
Two, similar compact server models have recently been proposed for the purpose of capturing the effects of server thermal mass in transient data center thermal simulations. Both models predict server exhaust temperature from a known inlet temperature at any time provided the server properties of thermal capacitance (heat capacity) and thermal effectiveness are known. One model also includes a third...
In an effort to improve the reliability and efficiency of data centers, racks and sometimes entire hot aisles are ducted to a dropped ceiling. The cooling performance of such systems strongly depends on IT and cooler airflow, the number and configuration of ducted objects and perforated ceiling tiles, the leakiness of the ceiling system, ceiling plenum depth, and other factors. Recently, a compact...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.