Control Systems for Heating, Ventilating, and Air Conditioning

317 Pages·1993·7.531 MB·English

by  Roger W. Haines, Douglas C. Hittle (auth.), Roger W. Haines, Douglas C. Hittle (eds.)

Control Systems
for Heating,
Ventilating,
and Air Conditioning
Fifth Edition
w.
Roger Haines
Consultant
and
Douglas C. Hittle
Director, Solar Energy Applications Laboratory
Colorado State University
ca
Ft. Collins,
SPRINGER SCIENCE+BUSINESS MEDIA, LLC
Copyright © 1993 by Springer Science+Busincss Media New York
Originally published by Van Nostrand Reinhold in 1993
AU rights reserved. No part ofthis book covered by the copyright hereon may be reproduced or used in any fonn or by any means--graphic, de,,'tronic.
<.lr mechanical, including photocopying, recording, taping, or information storage arul retrieval systerns--without the written permission ofthe
puhlisher.
J 4 5 6 7 8 9 XXX 01 00 99 98 97 96
Lihrary ofCongress Cataloging-in-Publication Data
Haincs. Roger W.
Control systems for heating, ventilating, and air conditioning, 5/e.
Bibliography: p.
lncludes index.
ISBN 978-1-4613-6359-0 ISBN 978-1-4615-3108-1 (eBook)
DOI 10.1007/978-1-4615-3108-1
1. Heating--Control. 2. Air conditioning--Control. 1. Title.
TII7466.5.H34 1993 82-11015
Vuit Chapman & Hall on the Internet http://www.chaphaLLcomichapha/Llltml
Contents
Preface to the First Edition ix
Preface to the Fifth Edition xi
Chapter 1 Control Theory and
Terminology 1
1.1 INTRODUCTION 1
1.2 WHAT IS "CONTROL"? 2
1.3 ELEMENTARY CONTROL SYSTEM 2
1.4 PURPOSES OF CONTROL 3
1.5 CONTROL ACTION 4
1.6 ENERGY SOURCES FOR CONTROL
SYSTEMS 9
1.7 MEASUREMENT 10
1.8 SYMBOLS AND ABBREVIATIONS 11
1.9 PSYCHROMETRICS 11
1.10 RELATIONSHIPS 11
1.11 SUMMARY 12
Chapter 2 Pneumatic Control Devices 13
2.1 INTRODUCTION 13
2.2 PNEUMATIC CONTROL DEVICES 13
2.3 CONTROL CABINETS 38
2.4 AIR SUPPLY 38
III
iv Contents
Chapter 3 Electric and Electronic Control
Devices 42
3.1 ELECTRIC CONTROL DEVICES 42
3.2 ELECTRONIC CONTROL
DEVICES 55
Chapter 4 Fluidic Control Devices 68
4.1 INTRODUCTION 68
4.2 WALL ATTACHMENT DEVICES 68
4.3 TURBULENCE AMPLIFIERS 70
4.4 VORTEX AMPLIFIERS 71
4.5 RADIAL JET AMPLIFIER 71
4.6 FLUIDIC TRANSDUCERS 72
4.7 MANUAL SWITCHES 73
Chapter 5 Flow Control Devices 75
5.1 DAMPERS 75
5.2 STEAM AND WATER FLOW CONTROL
VALVES 79
Chapter 6 Elementary Control
Systems 93
6.1 INTRODUCTION 93
6.2 OUTSIDE AIR CONTROLS 93
6.3 AIR STRATIFICATION 98
6.4 HEATING 100
6.5 COOLING COILS 105
6.6 HUMIDITY CONTROL 110
6.7 DEHUMIDIFIERS 118
6.8 STATIC PRESSURE CONTROL 119
6.9 ELECTRIC HEAT 120
6.10 GAS-FIRED HEATERS 123
6.11 OIL-FIRED HEATERS 125
6.12 REFRIGERATION EQUIPMENT 125
6.13 FIRE AND SMOKE CONTROL 131
6.14 ELECTRICAL INTERLOCKS 133
6.15 LOCATION OF SENSORS 133
6.16 SUMMARY 134
Contents v
Chapter 7 Complete Control Systems 135
7.1 INTRODUCTION 135
7.2 SINGLE-ZONE SYSTEMS 135
7.3 MULTIZONE AIR HANDLING
SYSTEMS 143
7.4 DUAL-DUCT SYSTEMS 157
7.5 VARIABLE-VOLUME SYSTEMS 162
7.6 REHEAT SYSTEMS 170
7.7 HEAT RECLAIM 170
7.8 FAN-COIL UNITS 178
7.9 INDUCTION SYSTEMS 183
7.10 UNIT VENTILATORS 184
7.11 PACKAGED EQUIPMENT 186
7.12 OTHER PACKAGED EQUIPMENT 189
7.13 RADIANT HEATING AND COOLING 191
7.14 RADIATORS AND CONVECTORS 193
7.15 HEAT EXCHANGERS 194
7.16 SOLAR HEATING AND COOLING
SYSTEMS 198
7.17 SUMMARY 199
Chapter 8 Electric Control Systems 200
8.1 INTRODUCTION 200
8.2 ELECTRIC CONTROL DIAGRAMS 200
8.3 ELECTRICAL CONTROL OF A
CHILLER 203
8.4 ELECTRICAL CONTROL OF AN AIR
HANDLING UNIT 206
8.5 EXAMPLE: A TYPICAL SMALL AIR-
CONDITIONING SYSTEM 206
8.6 ELECTRIC HEATERS 207
8.7 REDUCED-VOLTAGE STARTERS 211
8.8 MULTISPEED STARTERS 216
8.9 VARIABLE SPEED CONTROLLERS 219
8.10 SUMMARY 220
Chapter 9 Special Control 221
9.1 INTRODUCTION 221
9.2 CLOSE TEMPERATURE AND/OR HUMID
ITY CONTROL 221
vi Contents
9.3 CONTROLLED ENVIRONMENT ROOMS
FOR TESTING 227
9.4 SUMMARY 230
Chapter 10 Digital and Supervisory Control
Systems 231
10.1 INTRODUCfION 231
10.2 HARD-WIRED SYSTEMS 231
10.3 MULTIPLEXING SYSTEMS 232
10.4 COMPUTER-BASED SYSTEMS FOR
MONITORING AND CONTROL 232
10.5 BENEFITS OF THE COMPUTER
SYSTEM 239
10.6 TRAINING FOR MAINTENANCE AND
OPERATION 240
10.7 SUMMARY 240
Chapter 11 Psychrometries 242
11.1 INTRODUCfION 242
11.2 PSYCHROMETRIC PROPERTIES 242
11.3 PSYCHROMETRIC TABLES 244
11.4 PSYCHROMETRIC CHARTS 244
11.5 PROCESSES ON THE PSYCHROMETRIC
CHART 246
11.6 HVAC CYCLES ON THE CHART 250
11.7 IMPOSSIBLE PROCESSES 252
11.8 EFFECfS OF ALTITUDE 253
11.9 SUMMARY 254
Chapter 12 Central Plant Pumping and Distribution
Systems 255
12.1 INTRODUCfION 255
12.2 DIVERSITY 255
12.3 CONSTANT FLOW SYSTEMS 256
12.4 VARIABLE FLOW SYSTEMS 257
12.5 DISTRIBUTION SYSTEMS 259
12.6 BUILDING INTERFACES 263
12.7 SUMMARY 264
Contents vii
Chapter 13 Retrofit of Existing Control
Systems 265
13.1 INTRODUCTION 265
13.2 ECONOMIC ANALYSIS 265
13.3 DISCRIMINATORS 265
13.4 CONTROL MODES 266
13.5 ECONOMY CYCLE CONTROLS 266
13.6 SINGLE-ZONE SYSTEMS 266
13.7 REHEAT SYSTEMS 270
13.8 MULTIZONE SYSTEMS 270
13.9 DUAL-DUCT SYSTEMS 274
13.10 SYSTEMS WITH HUMIDITY
CONTROL 276
13.11 CONTROL VALVES AND PUMPING
ARRANGEMENTS 278
13.12 SUMMARY 279
Chapter 14 Dynamic Response and Tuning 280
14.1 INTRODUCTION 280
14.2 DYNAMIC RESPONSE 281
14.3 TUNING HVAC CONTROL LOOPS 282
14.4 SUMMARY 288
Bibliography 289
Abbreviations Used in This Book 292
Symbols Used in This Book 293
Index 301
Preface to the First Edition
This book is intended for the guidance of the engineer who is designing a
heating, ventilating or air conditioning system and wants a simple, practical
explanation of how best to control that system. It could also be used as a
supplemental text in a college or technical school course on refrigeration and
air conditioning.
It does not include mathematical analyses of control systems, response
factors, Fourier transforms and the like. These are adequately and thoroughly
covered in a number of up-to-date college-level texts.
What is presented here is an elementary but comprehensive explanation
of control system theory, control hardware, and both simple and complex
control systems. There are also discussions on supervisory controls and the
use of computers in control systems.
Throughout, the reader should be aware of the interrelationship between
the HVAC controls, the HVAC system, the electrical power system and the
building. There have been examples of control systems which failed to control
because inherent deficiences in the building or HVAC system made it uncon
trollable; or of control failures because the designer failed to make his intent
clear to others. It is hoped that the reader will be helped to avoid some of
these pitfalls.
Roger W. Haines
January, 1971
ix
Preface to the Fifth Edition
Roger Haines wrote in the Preface to the Fourth Edition that a new edition
was needed because technology changes so fast and that there is always
something new to learn.
Roger and I have been teaching short courses together for quite awhile.
Before the Fourth Edition of Roger's book came out I was seriously thinking
about writing my own book. After all, I had design experience and was doing
research on controls at the Construction Engineering Research Laboratory,
Champaign, Illinois. Most everything I had presented about new concepts
and products in HVAC controls between 1983 and 1986 was in Roger's
Fourth Edition (the book came out in 1987, but it takes a lot longer to go
from manuscript to published book).
I was devastated. All of our obscure research results were now published
in a semi-popular book. Well why not. Roger was trying to do his readers a
service and if you are out of date you are history. Roger stayed current and
my ambitions to do my own book were history.
Luckily, if you have sold all the Fourth Editions to all the people who are
likely to buy them, the publisher gives you a call and says it's time for a Fifth
Edition. Besides, there really had been some important work on HVAC
control going on at Universities and in the back rooms at control companies
in the interim.
When Roger called me and asked if I would consider revising his book I
was very pleased.
Here is a partial list of new material covered in this Fifth Edition:
1. Formulas and graphs. Math to allow you to determine the relationship
between damper position and flow rate, for example. Derivations of how
valve authority effects control system performance as another example.
xi
xii Preface
2. Much more on applications. This edition tries to give the pros and cons
of various control options. Energy consumption is one issue, maintainability
is also considered. An example of some of the revisions is the completely new
section on controlling variable-air-volume flow rates.
3. A revised discussion on digital control and central monitoring. If we print
the book fast enough this chapter will still be up-to-date.
4. A new chapter on dynamic response and control system tuning. Those who
master this chapter will be highly valued when it comes time to make a real
control system work.
I hope you can identify even more new material. Also, like Roger, I hope
you will help me learn. Please call me at (970-491-8617) if you have new
information that I should consider for the sixth edition.
Doug Hittle