HVAC Equations Data and Rules of Thumb

1 Arthur A. Bell Jr., PEHVACHVACE quations, Data, and Rules of ThumbMcGraw-HillNew York San Francisco Washington, Auckland Bogot Caracas Lisbon London Madrid Mexico City MilanMontreal New Delhi San Juan SingaporeSydney Tokyo TorontoLibrary of Congress Cataloging-in-Publication DataBell, Arthur : Equations , data, and Rules of Thumb / Arthur A. Bell, bibliographical references and 0-07-136129-41. Heating Mathematics Handbooks, manuals, Mathematics Handbooks, manuals, Airconditioning Mathematics Handbooks, manuals, Formulae Handbooks, manuals, .B45 2000697'.001'51 dc2100-025029 Copyright 2000 by The McGraw-Hill Companies, Inc. All rights reserved.

2 Printed in theUnited States of America. Except as permitted under the United States Copyright Act of1976, no part of this publication may be reproduced or distributed in any form or by anymeans or stored in a data base or retrieval system, without the prior written permission ofthe 2 3 4 5 6 7 8 9 0 DOC/DOC 0 6 5 4 3 2 1 0 ISBN 0-07-136129-4 The sponsoring editor for this book was Linda Ludewig, the editing supervisor was FrankKotowski, Jr., and the production supervisor was Pamela A. was set in Minion by North Market Street and bound by R. R. Donnelley & Sons, books are available at special quantity discounts to use as premiums and salespromotions, or for use in corporate training programs.

3 For more information, please writeto the Director of Special Sales, Professional Publishing, McGraw-Hill, Two Penn Plaza,New York, NY 10121-2298. Or contact your local book is printed on recycled, acid-free paper containing a minimum of 50%recycled, de-inked contained in this work has been obtained by The McGraw-Hill Compa-nies, Inc. ( McGraw-Hill ) from sources believed to be reliable. However, neitherMcGraw-Hill nor its authors guarantee the accuracy or completeness of any informa-tion published herein and neither McGraw-Hill nor its authors shall be responsible forany errors, omissions, or damages arising out of use of this information. This work ispublished with the understanding that McGraw-Hill and its authors are supplyinginformation but are not attempting to render engineering or other professional ser-vices.

4 If such services are required, the assistance of an appropriate professional shouldbe the AuthorArthur A. Bell, Jr., is a registered professional engineer with more than 15years experience designing HVAC systems. Bell has also been involved in thedesign of plumbing systems, fire protection systems, and construction fieldengineering-mechanical systems. He has taught ASHRAE HVAC classes, aswell as contractor training courses. A member of ASHRAE, ASPE, NFPA, AEI,and NSPE, he is a resident of Monaca, Equations , DATA, AND Rules OF THUMB2 PART heating, ventilation, and air conditioning (HVAC) Equations , data, Rules of Thumb ,and other information contained within this reference manual were assembled to aid thebeginning engineer and designer in the design of HVAC systems.

5 In addition, the experi-enced engineer or designer may find this manual useful as a quick design reference guideand teaching tool. The following pages compile information from various referencesources listed in Part 2 of this manual, from college HVAC class notes, from continuingeducation design seminars and classes, from engineers, and from personnel document was put together as an encyclopedic type reference in contract specifica-tion outline format where information could be looked up quickly, in lieu of searchingthrough volumes of text books, reference books and manuals, periodicals, trade articles,and product of Thumb listed herein should be used considering the following:A.

6 Building loads are based on building gross square Building loads generally include ventilation and make-up air Building loads should be calculated using the ASHRAE Handbook of Fundamen-talsor similar computational procedure in lieu of using these Rules of Thumb for finaldesigns. When calculating heating and cooling loads, actual occupancy, lighting, andequipment information should be obtained from the Owner, Architect, Electricalengineer, other design team members, or from technical publications such asASHRAE. These Rules of Thumb may be used to estimate system loads during thepreliminary design stages of a items contained herein were included more for comparison purposes than for useduring design.

7 All code items ( , BOCA, SBCCI, UBC, NFPA) are subject to change, andfederal, state, and local codes should be consulted for applicable regulations and require-ments. The following codes were used unless otherwise noted:A. 1990 Building Officials and Code Administrators International, Inc., (BOCA) TheBasic/National Building CodesB. 1993 Building Officials and Code Administrators International, Inc., (BOCA) TheBasic/National Building CodesC. 1988 Southern Building Code Congress International, Inc., (SBCCI) The Standard/Southern Building CodesD. 1988 International Conference of Building Officials, (ICBO) The Uniform BuildingCodesE. 1991 National Fire Protection Association (NFPA) special thanks to the following:A.

8 The Pittsburgh Chapter of ASHRAE Education Committee Members involved indeveloping the HVAC Design The students in the HVAC Design Class sponsored by the Pittsburgh Chapter The engineers at Henry Adams, Inc., in Baltimore, The engineers at Baker and Associates in Pittsburgh, The engineers at Industrial Design Corporation in Pittsburgh, 1. FOREWORD1 PART 2. REFERENCES AND DESIGN References and Design Building Codes11 PART 3. Contract Contractors/Manufacturers/Authorities26 PART 4. PROFESSIONAL SOCIETIES AND TRADE ORGANIZATIONS29 PART 5. Cooling and Heating R- Water System Air Change Rate Mixed Air Ductwork Fan Pump Pump Net Positive Suction Head (NPSH)

9 Air Conditioning Humidifier Sensible Heat Expansion Air Balance Cooling Towers and Heat Moisture Condensation on Calculating Heating Loads for Loading Ventilation of Mechanical Rooms with Refrigeration Equations for Flat Oval Pipe Expansion Steam and Condensate Steam and Steam Condensate Pipe Sizing Psychrometric Swimming Domestic Water Heater Domestic Hot Water Recirculation Pump/Supply Relief Valve Vent Line Maximum Relief Valve Steel Pipe English/Metric Cooling and Heating Equations Cooling Tower Motor Drive Formulas55 PART 6. COOLING LOAD Rules OF Offices, Banks, Court Houses, Municipal Buildings, Town Police Stations, Fire Stations, Post Precision Computer Kitchens (Depends Primarily on Kitchen Equipment) Cocktail Lounges, Bars, Taverns, Clubhouses, Hospital Patient Rooms, Nursing Home Patient Buildings w/100% OA Medical/Dental Centers, Clinics, and Apartments (Eff.)

10 , 1 Room, 2 Room) Motel and Hotel Public Motel and Hotel Guest Rooms, School Dining Halls, Lunch Rooms, Cafeterias, Libraries, Retail, Department Drug, Shoe, Dress, Jewelry, Beauty, Barber, and Other Malls, Shopping Auditoriums, Bowling All Cooling Load Calculation Cooling Load Peak Time Estimate66 PART 7. HEATING LOAD Rules OF All Buildings and Buildings w/100% OA Buildings w/Ample Insulation, Few Building w/Limited Insulation, Many Walls Below Grade (Heat Loss at Outside Air Design Condition) Floors Below Grade (Heat Loss at Outside Air Design Condition) Heating System Selection Heating Load Calculation Procedure69 PART 8.