Air Conditioning Engineering

531 Pages·2007·26.25 MB·English

Air Conditioning Engineering
This Page Intentionally Left Blank
Air Conditioning
Engineering
Fifth Edition
W.P. Jones
MSc, CEng, FlnstE, FCIBSE, MASHRAE
~~IE I N E M A N N
AMSTERDAM BOSTON HEIDELBERG LONDON NEW YORK OXFORD
PARIS SAN DIEGO SAN FRANCISCO SINGAPORE SYDNEY TOKYO
Elsevier Butterworth-Heinemann
Linacre House, Jordan Hill, Oxford OX2 8DP
30 Corporate Drive, Burlington, MA 01803
First published in Great Britain 1967
Second edition 1973
Third edition 1985
Fourth edition 1994
Reprinted 1996
Fifth edition 2001
Reprinted 2003, 2005
Copyright (cid:14)9 2001, W.P. Jones. All rights reserved
The right of W.P. Jones to be identified as the author of this work has been
asserted in accordance with the Copyright, Designs and Patents Act 1988
No part of this publication may be reproduced in any material form (including
photocopying or storing in any medium by electronic means and whether
or not transiently or incidentally to some other use of this publication) without
the written permission of the copyright holder except in accordance with the
provisions of the Copyright, Designs and Patents Act 1988 or under the terms of
a licence issued by the Copyright Licensing Agency Ltd, 90 Tottenham Court Road,
London, England W1T 4LP. Applications for the copyright holder's written
permission to reproduce any part of this publication should be addressed
to the publisher
Permissions may be sought directly from Elsevier's Science & Technology Rights
Department in Oxford, UK: phone: [phone], fax: [phone],
e-mail: [email protected]. You may also complete your request on-line via
the Elsevier homepage (http://www.elsevier.com), by selecting 'Customer Support'
and then 'Obtaining Permissions'
British Library Cataloguing in Publication Data
Jones, W.P. (William Pete0,
Air conditioning engineering.- 5th ed.
1. Air conditioning
I. Title
697.9'3
Library of Congress Cataloguing in Publication Data
Jones, W.P. (William Peter),
Air conditioning engineering/WP/Jones.- 5th ed.
p. cm.
Includes bibliographical references and index.
ISBN 0 7506 5074 5
1. Air conditioning. I. Title
TH7687.J618
697.9' 3-dc21 00-048640
ISBN 0 7506 5074 5
For information on all Elsevier Butterworth-Heinemann
publications visit our website at www.bh.com
I Working together to grow
libraries in developing countries
Typeset at Replika Press Pvt. Ltd, Delhi 110 040, India
Printed and bound in Great Britain by MPG Books Ltd, Bodmin, Cornwall
Preface to the Fifth Edition
Although the fundamentals of the subject have not altered since the publication of the last
edition there have been significant changes in the development and application of air
conditioning. Among these are concerns about indoor air quality, revision of outside design
data and the expression of cooling loads arising from solar radiation through glass by the
CIBSE. The phasing-out of refrigerants that have been in use for many years (because of
their greenhouse effect and the risks of ozone depletion) and the introduction of replacement
refrigerants are far-reaching in their consequences and have been taken into account. The
tables on the thermodynamic properties of refrigerant 22 have been deleted and new tables
for refrigerants 134a and ammonia substituted. There have also been new developments in
refrigeration compressors and other plant. Advances in automatic controls, culminating in
the use of the Internet to permit integration of the control and operation of all building
services worldwide, are very important. Revisions in expressing filtration efficiency, with
an emphasis on particle s'ize, have meant radical changes in the expression of the standards
used in the UK, Europe and the USA. The above developments have led to changes in the
content, notably in chapters 4 (on comfort), 5 (on outside design conditions), 7 (on heat
gains), 9 (for the refrigerants used), 12 (automatic controls) and 17 (on filtration standards).
Two examples on heat gains in the southern hemisphere have been included.
As with former editions, the good practice advocated by the Chartered Institution of
Building Services Engineers has been followed, together with the recommendations of the
American Society of Heating, Refrigerating and Air Conditioning Engineers, where
appropriate. It is believed that practising engineers as well as students will find this book
of value.
W.E Jones
This Page Intentionally Left Blank
Preface to the First Edition
Air conditioning (of which refrigeration is an inseparable part) has its origins in the
fundamental work on thermodynamics which was done by Boyle, Carnot and others in the
seventeenth and eighteenth centuries, but air conditioning as a science applied to practical
engineering owes much to the ideas and work of Carrier, in the United States of America,
at the beginning of this century. An important stepping stone in the path of progress which
has led to modern methods of air conditioning was the development of the psychrometric
chart, first by Carrier in 1906 and then by Mollier in 1923, and by others since.
The summer climate in North America has provided a stimulus in the evolution of air
conditioning and refrigeration which has put that semi-continent in a leading position
amongst the other countries in the world. Naturally enough, engineering enterprise in this
direction has produced a considerable literature on air conditioning and allied subjects.
The Guide and Data Book published by the American Society of Heating, Refrigeration
and Air Conditioning has, through the years, been a foremost work of reference but, not
least, the Guide to Current Practice of the Institution of Heating and Ventilation Engineers
has become of increasing value, particularly of course in this country. Unfortunately,
although there exists a wealth of technical literature in textbook form which is expressed
in American terminology and is most useful for application to American conditions, there
is an almost total absence of textbooks on air conditioning couched in terms of British
practice. It is hoped that this book will make good the dificiency.
The text has been written with the object of appealing to a dual readership, comprising
both the student studying for the associate membership examinations of the Institution of
Heating and Ventilating Engineers and the practising engineer, with perhaps a 75 per cent
emphasis being laid upon the needs of the former. To this end, the presentation follows the
sequence which has been adopted by the author during the last few years in lecturing to
students at the Polytechnic of the South Bank. In particular, wherever a new idea or
technique is introduced, it is illustrated immediately by means of a worked example, when
this is possible. It is intended that the text should cover those parts of the syllabus for the
corporate membership examination that are relevant to air conditioning.
Inevitably some aspects of air conditioning have been omitted (the author particularly
regrets the exclusion of a section on economics). Unfortunately, the need to keep the book
within manageable bounds and the desire to avoid a really prohibitive price left no choice
in the matter.
W.E Jones
Acknowledgements
Originally this book was conceived as a joint work, in co-authorship with Mr. L.C. Bull.
Unfortunately, owing to other commitments, he was compelled largely to forego his interest.
However, Chapters 9 and 14 (on the fundamentals of vapour-compression and vapour-
absorption refrigeration) are entirely his work. The author wishes to make this special
acknowledgement to Mr. Bull for writing these chapters and also to thank him for his
continued interest, advice and encouragement. Sadly, Mr. Bull is now deceased.
The helpful comment of Mr. E. Woodcock is also appreciated.
The author is also indebted to Mr. D.J. Newson for his contribution and comment.
The author is additionally grateful to the following for giving their kind permission to
reproduce copyright material which appears in the text.
The Chartered Institution of Building Services Engineers for Figures 5.4 and 7.16, and
for Tables 5.3, 5.4, 7.2, 7.7, 7.13, 7.14, 7.18, 16.1 and 16.2 from the CIBSE Guide.
H.M. Stationery Office for equation (4.1) from War Memorandum No. 17, Environmental
Warmth and its Measurement, by T. Bedford.
Haden Young Ltd. for Tables 7.9 and 7.10.
The American Society of Heating, Refrigeration and Air Conditioning Engineers for
Tables 7.5, 9.1, 9.2 and for Figure 12.12.
John Wiley & Sons Inc., New York, for Figure 13.8 from Automatic Process Control by
D.P. Eckman.
McGraw-Hill Book Company for Table 7.12.
American Air Filter Ltd. (Snyder General) for Table 9.6.
Woods of Colchester Ltd. for Figure 15.23.
W.B. Gosney and O. Fabris for Tables 9.3 and 9.4.
Contents
Preface to the Fifth Edition v
Preface to the First Edition vii
Acknowledgement viii
1. The Need for Air Conditioning
1.1 The meaning of air conditioning 1
1.2 Comfort conditioning 1
1.3 Industrial conditioning 2
2. Fundamental Properties of Air and Water Vapour Mixtures 3
2.1 The basis for rationalisation 3
2.2 The composition of dry air 3
2.3 Standards adopted 5
2.4 Boyle's law 6
2.5 Charles' law 7
2.6 The general gas law 9
2.7 Dalton's law of partial pressure 11
2.8 Saturation vapour pressure 12
2.9 The vapour pressure of steam in moist air 13
2.10 Moisture content and humidity ratio 16
2.11 Percentage saturation 18
2.12 Relative humidity 19
2.13 Dew point 20
2.14 Specific volume 21
2.15 Enthalpy: thermodynamic background 22
2.16 Enthalpy in practice 23
2.17 Wet-bulb temperature 25
2.18 Temperature of adiabatic saturation 28
2.19 Non-ideal behaviour 30
2.20 The triple point 33
3. The Psychrometry of Air Conditioning Processes 38
3.1 The psychrometric chart 38
3.2 Mixtures 39
3.3 Sensible heating and cooling 42
3.4 Dehumidification 44
3.5 Humidification 48
3.6 Water injection 52
3.7 Steam injection 54