Particulate And Gaseous Contamination In Datacom Environments Pdf Free

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Structural and Vibration Guidelines for Datacom Equipment Particulate and gaseous contamination monitoring, prevention, and control in datacom environments have gained greater importance because of an increase in datacom equipment reliability concerns arising from a multitude of factors: mission-critical societal dependence on computers; continued miniaturization of electronic circuit features; elimination of lead from printed circuit board solder metallurgies; proliferation of datacom equipment into geographies with high levels of sulfur-bearing contamination; increased use of free-air cooling to conserve energy; and expansion of the allowable temperature-humidity IT and datacom equipment envelope. The second edition of Particulate and Gaseous Contamination in Datacom Environments describes in detail the procedures necessary to ensure airborne contaminants will not be a factor determining datacom equipment reliability.

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For personal use only. This file is licensed to sergio torres morales retos correoinfinitum. This publication was prepared in cooperation with TC 9. Particulate and Gaseous Contamination in Datacom Environments. All rights reserved. Printed in the United States of America. Printed on post-consumer waste using soy-based inks.

Cover photograph used with permission of Crispin R. The appearance of any technical data or editorial material in this publication does not constitute endorsement, warranty, or guaranty by ASHRAE of any product, service, process, procedure, design, or the like. The entire risk of the use of any information in this publication is assumed by the user.

No part of this book may be reproduced without permission in writing from ASHRAE, except by a reviewer who may quote brief passages or reproduce illustrations in a review with appropriate credit; nor may any part of this book be reproduced, stored in a retrieval system, or transmitted in any way or by any means—electronic, photo- copying, recording, or other—without permission in writing from ASHRAE.

Requests for permission should be submitted at www. Library of Congress Cataloging-in-Publication Data Particulate and gaseous contamination in datacom environments. Summary: "Provides the reader with information they need to maintain a high level of IT equipment depend- ability and availability by identifying datacom equipment susceptibility to particulate and gaseous contamina- tion and the operational impact, as well as strategies for prevention, control, contamination testing, and analysis"--Provided by publisher.

ISBN softcover 1. Clean rooms. Data processing service centers--Protection. Electronic data processing--Equipment and supplies--Protection. Air filters. Dust control. Contamination Technology 7.

Decontamination from gases, chemicals, etc. P37 Contents Acknowledgments. Roger Schmidt of IBM for his vision and thorough review of multiple drafts of this book. Christian Belady of Microsoft for his vision and leadership in the cre- ation of this book. John Quick of IBM for his invaluable contributions in researching and writing material for this book. Joe Prisco of IBM for his overall leadership and editing of multiple drafts of this book.

Introduction Datacom equipment center owners and operators focus much of their attention on the physical structure and performance of the datacom infrastructure environ- ment e. Datacom equipment center contamination is frequently overlooked and, if left unrestrained, can degrade the reliability and the continuous operation of mission-critical IT equipment within a facility. To maintain a high level of IT equipment dependability and availability, it is crit- ical to view contamination in a holistic way.

It should be acknowledged that the data- com equipment center is a dynamic environment where many maintenance operations, infrastructure upgrades, and IT equipment change activities occur on a regular basis. Airborne contaminants harmful to sensitive electronic devices can be introduced into the operating environment in many ways during these and other activities.

The funda- mental focus areas that necessitate examination start with the outdoor ambient air pollutants surrounding the facility. Outdoor air that purposely enters the building for datacom equipment center free cooling, datacom equipment center positive pressur- ization, or human occupancy air changes must be filtered and possibly conditioned.

Data- com workers also add contamination from hair, lint on clothing, and other contami- nants tracked in on footwear to the datacom equipment center. With proper planning and controls, datacom equipment center operators can minimize contamination and potential negative effects in the datacom equipment center. Datacom managers and operators should include a datacom equipment center environmental contamination section as part of the standard operating procedure.

The association between contamination and hardware failures is often overlooked. Occasionally, the absence of contamination controls results from cost-cutting actions or from lack of knowledge.

Particle and gaseous contamination can result in intermittent equipment glitches or in unplanned shutdowns of critical systems that often mean significant business and financial losses. Examples of contamination events are provided throughout the book. In many cases, the events are written gener- ically to illustrate points that support the text. The intent of this publication is to provide basic information that is essential to the control and prevention of particulate and gaseous contamination within datacom facilities.

Understanding the critical parameters outlined in this publication will provide equipment manufacturers and facilities operations personnel with a common set of guidelines for contamination control that can enhance the longevity of datacom equipment.

The book does not cover issues related to contamination and filtration of open water systems, such as condenser water systems, used in datacom environments.

The intended audience for this publication is:. For the purposes of this book, the terms particle, particulate, aerosol, and dust will be considered equivalent and all are represented by the term PM. The size of PM spans a vast size range from 0. More specif- ically, PM can be categorized in three size modes: fine mode 0. PM in each of these size categories may be composed of differ- ent materials, come from different sources, and vary in airborne suspension life- time. See Figure 1.

Consequently, PM. I-P conversions: 0. This book discusses particles in each of these size modes. The gases can occur naturally or can be by-products of indus- trial or manufacturing processes.

Gases tend to occupy an entire air volume uniformly at standard room pressure and temperature. The gases can either act alone or in conjunction with other gases or PM to form compounds that can result in oxidation on metallic materials.

The oxidation results from a chemical reaction, which causes irreversible destruction on the surface of a circuit board, on the leads of a connector, or on pins of an integrated circuit. Gaseous contamination in the form of outside pollution e. PM is generated both naturally and by humans anthropogenically. In the outdoors, fine-mode 0. Significant urban PM sources include automobiles, electricity generation, and wood-burning fireplaces Seinfeld and Pandis Larger particles can include sea salt, natural and artificial fibers, plant pollens, and wind-blown dust.

Accumulation-mode particles are the PM of principal concern when outdoor air is enter- ing the datacom equipment center environment. Figure 1. More information about air filtration can be found in Chapter 4. Particles with diameters larger than about 1. This causes these larger particles to crash into the filter fibers.

Particles smaller than about 0. Particles in the in-between range the accumulation-mode size range are most difficult to remove, because these particles most easily follow the airflow through the filter fibers.

Outdoor particles beyond the accumulation-mode size range can enter datacom equipment centers through openings in the building envelope, but data- com equipment centers can be positively pressurized to avoid this form of particle infil- tration. However, one study indicates that introduction of outdoor air for the sole purpose of guarding against infiltration actually carries more particles into the building than the added pressure keeps out Herrlin Previous measurements have shown outdoor air to be the main source of PM in the data center environment Shehabi et al.

Indoor-generated PM can include particles in all size ranges. Fan belt wear in air-handling units AHU , toner dust from copiers, and printers can be sources of coarse-mode particles.

Coarse-mode particles can also come from occupant hair and clothing or occupant activities, such as the unpacking of equip- ment or construction e.

Other documented fibers include small zinc formations, commonly referred to as zinc whiskers, which have been observed forming on the surface of zinc electroplated steel. Gases entering the datacom equipment center from the outdoors can react once inside the environment and form particles in the fine- and accumulation- mode size range. PM is transported with the movement of air, also known as advection, throughout the datacom equipment center.

Datacom equipment centers can be raised-access floor or non-raised-access floor envi- ronments. Outside air, also referred to as makeup air, enters the side of the AHU, where it passes through a series of filters and is conditioned. The conditioned air is then supplied to the servers through the raised floor.

Fans within the datacom equipment pull air through the. Most air circulation in datacom centers is internal to the datacom center zone.

The majority of datacom centers are designed to have only a small portion of outside air enter the datacom center for positive pressurization.

Some datacom centers provide no ductwork for outside air to directly enter the datacom center area. Rather, outside air is only provided by infiltration from adjacent zones, such as office spaces or hallways. However, a growing number of datacom centers use air handlers designed with air-side economizers similar to those used in commercial build- ings to take advantage of the energy- efficiency benefit of using a high volume of outside air for cooling.

It should be noted that the traditional closed-flow layout results in the same air circulating through filters repeatedly. The intake of large volumes of external air and its subsequent exhaust from the datacom equipment center results in fewer passes through the filtration system for any given volume of air. PM deviates from airflow paths and settles onto interior surfaces primarily through three different mechanisms:. Gravitational settling is a function of particle mass and has the greatest influ- ence on large particles.

Strong air currents can prolong airborne residence times, even for large particulates. The diffusional movement of PM is caused by random collision of air molecules against airborne particles. The result of these collisions allows particles to migrate from higher particle concentrations to lower particle concentrations. Diffusion is significant only with very small particles and has minimal influence on particles greater than 0.

Diffusion affects particles equally in all directions. While larger particles primarily deposit onto horizontal surfaces, smaller particles have an equal tendency to deposit on either horizontal or vertical surfaces.

China RoHS: How the Changing Regulatory Landscape Is Affecting Process Equipment Reliability

Want a reliable data center? You need to understand how contamination happens - and how to prevent it. Maximizing the life of server, storage and other electronic equipment within the data center will increase operational efficiency and add value to the organization, even though the IT equipment lifecycle may be as short as three years. UPS, servers, hard drives and other sensitive electronic equipment failures are on the increase in sites where stringent airborne contamination policies are not in place. Data centers, from initial build to refit are dynamic environments. Critical engineering infrastructure upgrades, total equipment change-out, and even simply opening doors or entering or exiting a white space provide opportunities to introduce contaminants. These contaminants affect electronic equipment, corroding contacts and reducing capabilities to failure point, which can result in costly data center outages.

Dust is ubiquitous. Even with the best filtration efforts, dust will be present in a data center and will settle on electronic hardware. Failure modes due to dust include but are not limited to the following:. Mechanical effects. Mechanical effects include obstruction of cooling airflow, interference with moving parts, abrasion, optical interference, interconnect interference, or deformation of surfaces e. Chemical effects.

For personal use only. This file is licensed to sergio torres morales retos correoinfinitum. This publication was prepared in cooperation with TC 9. Particulate and Gaseous Contamination in Datacom Environments. All rights reserved. Printed in the United States of America. Printed on post-consumer waste using soy-based inks.

Data Center Contamination

Manuscript received December 16, ; final manuscript received March 24, ; published online April 24, Editor: Justin A. Shah, J.

Communication Systems and Information Technology pp Cite as. These regulations require the elimination of lead in electronic products and manufacturers now have to comply with RoHS if they want to continue to do business in the EU and China. Corrosion-induced failures were frequent in industrial process control systems even before RoHS regulations with a typical failure mechanism being the reaction of atmospheric sulfur with exposed metals. Corrosion can occur quite rapidly in humid environments especially in the presence of small amounts of atmospheric sulfur and chlorides resulting in e.

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4 Response
  1. Thomas G.

    In , a group of thermal engineers from different IT manufacturing companies formed a thermal management consortium.

  2. Aien V.

    In , a group of thermal engineers from different IT manufacturing companies formed a thermal management consortium.

  3. Subtcintdernre

    ronmental Guidelines for Datacom Equipment—Expanding the Particulate and Gaseous Contamination in Datacom Environments (ASHRAE a). Guidelines for Data Processing Environments [ASHRAE b]; a free supplement.

  4. Tifilulos

    similar problems especially when using air-side economizers for “free cooling. Desktop and laptop computers, servers, data communications (datacom) Corrosive gases and submicron particulates in urban environments come from motor.

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