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Gatley The Comprehensive Guide to Psychrometrics Understanding Psychrometrics serves as a lifetime reference manual and basic refresher course for those who use psychrometrics on a recurring basis and provides a four- to six-hour psychrometrics learning module to students; air- conditioning designers; agricultural, food process, and industrial process engineers; Understanding Psychrometrics meteorologists and others. Understanding Psychrometrics Third Edition New in the Third Edition • Revised chapters for wet-bulb temperature and relative humidity and a revised Appendix V that includes a summary of ASHRAE Research Project RP-1485. • New constants for the universal gas constant based on CODATA and a revised molar mass of dry air to account for the increase of CO2 in Earth’s atmosphere. • New IAPWS models for the calculation of water properties above and below freezing. • New tables based on the ASHRAE RP-1485 real moist-air numerical model using the ASHRAE LibHuAirProp add-ins for Excel®, MATLAB®, Mathcad®, and EES®. Includes Access to Bonus Materials and Sample Software • PDF files of 13 ultra-high-pressure and 12 existing ASHRAE psychrometric charts plus three new 0ºC to 400ºC charts. • A limited demonstration version of the ASHRAE LibHuAirProp add-in that allows users to duplicate portions of the real moist-air psychrometric tables in the ASHRAE Handbook—Fundamentals for both standard sea level atmospheric pressure and pressures from 5 to 10,000 kPa. • The hw.exe program from the second edition, included to enable users to compare the 2009 ASHRAE numerical model real moist-air psychrometric properties with the 1983 ASHRAE-Hyland-Wexler properties. Praise for Understanding Psychrometrics, Third Edition It’s really a mine of information. If you are involved in meteorology, food science or HVAC and want to understand psychrometrics, get this book! Bruce Wernick, PrEng BScEng, TechniSolve Software Third Edition The book is not only informative and authoritative, it is charming—a characteristic seldom seen in technical publications. Lew Harriman, co-author of Humidity Control Design Guide for Commercial and Institutional Buildings ISBN: 978-1-936504-31-2 Donald P. Gatley, PE, Fellow ASHRAE, has over fifty years of experience in design/build mechanical contracting, moisture control, and consulting engineering. He is a recipient of Donald P. Gatley the ASHRAE Distinguished Service Award and two ASHRAE 9 781936 504312 International Energy Awards. Product code: 90167 1/13 Please visit our online bookstore at www.ashrae.org/bookstore. Understanding Psychrometrics 3rd.indd 1 1/9/2013 10:08:56 AM © 2013 ASHRAE (www.ashrae.org). For personal use only. Additional reproduction, distribution, or transmission in either print or digital form is not permitted without ASHRAE's prior written permission. Understanding Psychrometrics Third Edition © 2013 ASHRAE (www.ashrae.org). For personal use only. Additional reproduction, distribution, or transmission in either print or digital form is not permitted without ASHRAE's prior written permission. About the Author Donald P. Gatley, PE, Fellow ASHRAE, is a 1954 mechanical engineering graduate of Vanderbilt University. His career includes 13 years with the Trane Company, 8 years in design/build mechanical contracting, and 30+ years in the practice of consulting engineer- ing. Outside activities include service as chair of Georgia’s building energy code committee and as president of the Southface Energy Institute. He is known for his work in the prevention and correction of building moisture problems, energy conservation in buildings, and with hotels. He is a recipient of the ASHRAE Distinguished Service Award and two ASHRAE International Energy Awards. Gatley also authored the EPRI Cool Storage Ethylene Glycol Design Guide (1992), the EPRI Cool Storage Open Hydronic Systems Design Guide (1995) and two chapters of the Mold & Mildew Handbook published by the American Hotel and Motel Association (1991) and co-authored Moisture and Mildew Control (1992). He has written more than 30 articles on flow diagrams, central drinking water systems, the control of DX cooling coils, life-cycle cost of central chilled water plants, effective air-side design, gas phase filtration of exhaust air, thermal storage systems, quieting residential systems, moisture control in the home, and enhanced dehumidification systems. In 2003, he joined with Professors Sebastian Herrmann and Hans-Joachim Kretzschmar of the Department of Technical Thermodynamics, Zittau/Goerlitz University of Applied Sciences, Zittau, Germany for four psychrometric research projects: • Determination of a Twenty-First Century Molar Mass for Dry Air • Determination of Thermodynamic and Transport Properties of Humid Air for Power-Cycle Calculations for PTB-Bericht • RP-1485, Thermodynamic Properties of Real Moist Air, Dry Air, Steam, Water, and Ice for ASHRAE • Real Humid Air Psychrometric Function Add-Ins named LibHuAirProp for Excel®, MATLAB®, Mathcad®, and EES®. Updates/errata for this publication will be posted on the ASHRAE website at www.ashrae.org/publicationupdates. © 2013 ASHRAE (www.ashrae.org). For personal use only. Additional reproduction, distribution, or transmission in either print or digital form is not permitted without ASHRAE's prior written permission. Understanding Psychrometrics Third Edition Donald P. Gatley © 2013 ASHRAE (www.ashrae.org). For personal use only. Additional reproduction, distribution, or transmission in either print or digital form is not permitted without ASHRAE's prior written permission. ISBN 978-1-936504-31-2 © 2002, 2005, 2013 ASHRAE. All rights reserved. 1791 Tullie Circle, NE · Atlanta, GA 30329 · www.ashrae.org ASHRAE is a registered trademark of the American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc. Printed in the United States of America Cover design by Tracy Becker ASHRAE has compiled this publication with care, but ASHRAE has not investigated, and ASHRAE expressly disclaims any duty to investigate, any product, service, process, proce- dure, design, or the like that may be described herein. The appearance of any technical data or editorial material in this publication does not constitute endorsement, warranty, or guar- anty by ASHRAE of any product, service, process, procedure, design, or the like. ASHRAE does not warrant that the information in the publication is free of errors, and ASHRAE does not necessarily agree with any statement or opinion in this publication. The entire risk of the use of any information in this publication is assumed by the user. No part of this publication 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 publication be reproduced, stored in a retrieval system, or transmitted in any way or by any means—electronic, photocopying, recording, or other—without permission in writing fromASHRAE. Requests for permission should be submitted at www.ashrae.org/permissions. Library of Congress Cataloging-in-Publication Data Gatley, D. P. Understanding psychrometrics / Donald P. Gatley.—Third edition. pages cm Includes bibliographical references and index. Summary: “Updates the second edition to provide readers a reference that agrees with the latest international standards. The third edition also includes a revised equation for the adiabatic saturation process, an summary of the 2009 RP-1485 ASHRAE research, as well as minor edits to the text”— Provided by publisher. ISBN 978-1-936504-31-2 (hardcover) 1. Hygrometry. 2. Humidity. I. American Society of Heating, Refrigerating and Air-Conditioning Engineers. II. Title. QC915.G37 2012 551.57'10287--dc23 2012042195 ASHRAE STAFF SPECIAL PUBLICATIONS Mark Owen, Editor/Group Manager of Handbook and Special Publications Cindy Sheffield Michaels, Managing Editor Matt Walker, Associate Editor Roberta Hirschbuehler, Assistant Editor Sarah Boyle, Editorial Assistant Michshell Phillips, Editorial Coordinator PUBLISHING SERVICES David Soltis, Group Manager of Publishing Services and Electronic Communications Tracy Becker, Graphics Specialist Jayne Jackson, Publication Traffic Administrator PUBLISHER W. Stephen Comstock © 2013 ASHRAE (www.ashrae.org). For personal use only. Additional reproduction, distribution, or transmission in either print or digital form is not permitted without ASHRAE's prior written permission. This book is dedicated to those new to psychrometrics and to professionals and technicians who need information and underlying principles in convenient format. May the form of presentation and contents save time and make your journeys into psychrometrics valuable and enjoyable. © 2013 ASHRAE (www.ashrae.org). For personal use only. Additional reproduction, distribution, or transmission in either print or digital form is not permitted without ASHRAE's prior written permission. © 2013 ASHRAE (www.ashrae.org). For personal use only. Additional reproduction, distribution, or transmission in either print or digital form is not permitted without ASHRAE's prior written permission. Contents Acknowledgments . .ix Preface . .xi Preface to the Third Edition. xv Introduction 1—How to Use this Book . 3 2—Etymology. 9 3—Moist Air—The Psychrometric Substance . .13 4—Water Vapour . .19 5—Basics of the Psychrometric Chart . .31 6—Underlying Theory and Algorithms . 37 7—Ideal Gas . 43 8—Psychrometric Pioneers and Charts from the First 100 Years . 49 Part I: Psychrometric Pioneers.
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