Document eyxDe3wb36zZjXbaprv762O9
Copyright 1949
'' BY THE
American Society of Heating and. Ventilating Engineers and by IT Dedicated
To the Advancement of The Profession
and
Its Allied Industries
TEXT AND ILLUSTRATIONS ARE FULLY PRO TECTED BY COPYRIGHT AND NOTHING THAT APPEARS MAY BE REPRINTED EITHER WHOLLY ,
JOR IN PART WITHOUT SPECIAL PERMISSION.
Printed and Bound by Wavebly Press, Inc. BALTIMORE MARYLAND
D. S. A.
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PREFACE TO THE 27th EDITION
IN THE revision of The Heating Ventilating Air Conditioning Guide for the 1949 edition, all chapters have been examined and improvements have been made wherever current
engineering practice or recent published data have indicated progress or change in the presen
tation of the subject. The Technical Data Section has been enlarged by 80 pages, and the
Catalog Data Section has been increased by the addition of up-to-date products of many
.additional manufacturers.
Particular attention is called to the revision of the following chapters:
Chapter 1--Terminology. Many definitions have been added to the previous list.
Chapter 4--Fluid Flow. The theory and mathematical background for fluid flow compu
tations have been enlarged upon and a section has been added on variable-area flow meters.
Chapter 6--Heat Transmission Coefficients of Building Materials. The section on vapor
transmission has been enlarged and the method of computing the overall heat transfer coeffi
cient of walls having high conductivity members has been expanded and improved. Federal
specifications for water-proofed building papers have been added.
Chapter 10--Air Contaminants. Revisions have been made in tables of permissible limits
of contaminants wherever changes have been found in accepted values.
Chapter 11--Instruments and Measurements. Descriptions and comments on use of several
additional instruments have been added. The chapter has been extensively revised and
portions rewritten to clarify principles of operation and to indicate precision of various
measurements.
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' Chapter 12--Physiological Principles. Revisions in sections relating to human reactions
to extremes of hot and cold environments have brought data on these effects up to date with
most recent research, and also with findings of the Armed Services.
Chapter IS--Air Conditioning in the Prevention and Treatment of Disease. The text has
been coordinated with present medical conclusions in regard to environmental conditions
found most beneficial in treatment of disease.
Chapter Urr-Heating Load. Data on tabulated winter climatic conditions have been
extended by addition of new information received from the U. S. Weather Bureau.
Chapter 15--Cooling Load. The calculation of solar heat gain through walls and roofs has
been simplified by means of tables providing equivalent temperature differentials which can
be used with the heat transfer coefficients of the structure to obtain the heat transfer resulting
from solar radiation, as well as air temperature difference. The tables also contain correction
factors to permit application to other than tabulated conditions. Tabulated climatic condi
tions have been brought up to date by new data furnished by the U. S. Weather Bureau.
Chapter 17--Automatic Fuel Burning Equipment. The section on Vaporizing Oil Burners
has been enlarged. Tables and data on sizing of gas piping to appliances have been added.
Chapter 18--Heating Boilers, Furnaces, Space Heaters. A section has been added to cover
space heaters, their design, rating, installation and operation.
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Chapter 22--Mechanical Warm Air Systems. The chapter has been completely revised in
conformity with latest recommendations of the NWAH&ACA. A section, Design Procedure
for Large Systems, has been added. Chapter 2$--Steam Heating Systems and Piping. The section referring to traps has been
rewritten and illustrations of various types of traps added. The range of steam main and,
riser capacities has been extended for two-pipe systems. Many new diagrams showing piping
connections to heating coils have been included.
Chapter 26--Unit.Heaters, Unit Ventilators, Unit Humidifiers. Improved air vent piping
connections are shown in unit heater piping diagram.
Chapter SO^Electric Heating. Sections pertaining-to Resistors and Heating Elements,
Unit Heaters, and Electric Heating by Induction and Dielectric means, have been rewritten.
Chapter S3--Air Cleaning Devices. Dust Collectors are discussed in a new section which
covers types, application and selection of collectors for industrial use.
Chapter 85--Motors and Motor Controls. Revisions have been made wherever necessary
to insure compliance with -present motor and motor control practice and specifications.
Descriptions of types of motors have been improved. Chapter 37--Spray Apparatus. The entire sections dealing with cooling towers and spray
ponds have been revised and rewritten to include description of current equipment and to
present up-to-date design information. Factors affecting location, selection and performance
of cooling towers are given. Illustrations of various types of towers are included.
Chapter S9--Refrigeration. A thorough revision improving the presentation of the subject
includes a new section on the heat pump, and added pressure-enthalpy charts for ammonia
and "Freon-lfc". Revised tables are supplied for sizing of refrigerant piping. Emphasis is
placed upon application of refrigeration equipment.
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