Principles of heating ventilating and air conditioning

It is suitable both as a textbook and as a reference book for undergraduate engineering courses in the field of air conditioning, heating, and ventilation; for similar courses at technical and vocational schools; for continuing education and refresher short courses for engineers; and for adult education courses for professionals other than engineers, especially when combined with ASHRAE Handbook— Fundamentals The material is divided into three major sections: general concepts, Chapters 1–10; air-conditioning systems, Chapters 11–16; and HVAC&R equipment, Chapters 17–20 There are several significant changes in this revised edition Chapter has new values for climatic design information Chapter has been extensively revised with new design data In addition, the chapters on system design and equipment have been significantly revised to reflect recent changes and concepts in modern heating and air-conditioning system practices This book includes access to a website containing the Radiant Time Series (RTS) Method Load Calculation Spreadsheets, which are intended as an educational tool both for the student and for the experienced engineer wishing to explore the RTS method These spreadsheets allow the user to perform RTS cooling load calculations for lights, people, equipment, walls/roofs, and fenestration components using design day weather profiles for any month Cooling and heating loads can be calculated for individual rooms or block load zones Twelve-month cooling calculations can be done to determine the month and time of peak cooling load for each room or block load zone In addition, room/zone worksheets can be copied and modified within the spreadsheet to analyze as many rooms or zones as desired; the number of rooms/zones is limited only by the available computer memory Principles of HVAC Principles of Heating, Ventilating, and Air Conditioning is a textbook based on the 2017 ASHRAE Handbook—Fundamentals It contains the most current ASHRAE procedures and definitive, yet easy to understand, treatment of building HVAC systems, from basic principles through design and operation 8th Edition Principles of Heating Ventilating and Air Conditioning 8th Edition Based on the 2017 ASHRAE Handbook—Fundamentals Ronald H Howell ISBN: 978-1-939200-73-0 (hardback) 978-1-939200-74-7 (PDF) ASHRAE 1791 Tullie Circle Atlanta, GA 30329-2305 404-636-8400 (worldwide) www.ashrae.org PHVAC TEXT_cover.indd Tai ngay!!! 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Product Code:200730 90567 7/17 781939 7/12/2017 12:01:20 PM PRINCIPLES OF HEATING VENTILATING AND AIR CONDITIONING ABOUT THE AUTHORS Ronald H Howell, PhD, PE, Fellow/Life Member ASHRAE, retired as professor and chair of mechanical engineering at the University of South Florida and is also professor emeritus of the University of Missouri-Rolla For 45 years he taught courses in refrigeration, heating and air conditioning, thermal analysis, and related areas He has been the principal or co-principal investigator of 12 ASHRAE-funded research projects His industrial and consulting engineering experience ranges from ventilation and condensation problems to the development and implementation of a complete air curtain test program The following authors contributed significantly to the textbook Principles of Heating, Ventilating, and Air Conditioning They recently passed away and were not part of the 2017 revisions William J Coad, PE, Fellow ASHRAE, was ASHRAE president in 2001-2002 He was employed with McClure Engineering Associates, St Louis, Mo., for 45 years He was also president of Coad Engineering Enterprises He served as a consultant to the Missouri state government and was a lecturer in mechanical engineering for 12 years and an affiliate professor in the graduate program for 17 years at Washington University, St Louis He was the author of Energy Engineering and Management for Building Systems (Van Nostrand Reinhold) Mr Coad passed away in August 2014 Harry J Sauer, Jr., PhD, PE, Fellow ASHRAE, was a professor of mechanical and aerospace engineering at the University of Missouri-Rolla He taught courses in air conditioning, refrigeration, environmental quality analysis and control, and related areas His research ranged from experimental boiling/condensing heat transfer and energy recovery equipment for HVAC systems to computer simulations of building energy use and actual monitoring of residential energy use He served as an advisor to the Missouri state government and has conducted energy auditor training programs for the US Department of Energy Dr Sauer passed away in June 2008 PRINCIPLES OF HEATING VENTILATING AND AIR CONDITIONING 8th Edition A Textbook with Design Data Based on the 2017 ASHRAE Handbook—Fundamentals Ronald H Howell Atlanta ISBN 978-1-939200-73-0 (hardback) 978-1-939200-74-7 (PDF) © 1990, 1994, 1998, 2001, 2005, 2009, 2013, 2017 ASHRAE 1791 Tullie Circle, N.E Atlanta, GA 30329 www.ashrae.org All rights reserved Printed in the United States of America ASHRAE is a registered trademark in the U.S Patent and Trademark Office, owned by the American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc ASHRAE has compiled this publication with care, but ASHRAE has not investigated, and ASHRAE expressly disclaims any duty to investigate, any product, service, process, procedure, 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 guaranty 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 from ASHRAE Requests for permission should be submitted at www.ashrae.org/permissions Names: Howell, Ronald H (Ronald Hunter), 1935- author Title: Principles of heating ventilating and air conditioning : a textbook with design data based on the 2017 ashrae handbook of fundamentals / Ronald H Howell Description: 8th edition | Atlanta : ASHRAE, [2017] | Includes bibliographical references and index Identifiers: LCCN 2017033377| ISBN 9781939200730 (hardcover : alk paper) | ISBN 9781939200747 (pdf) Subjects: LCSH: Heating Textbooks | Ventilation Textbooks | Air conditioning Textbooks Classification: LCC TH7012 H73 2017 | DDC 697 dc23 LC record available at https://lccn.loc.gov/2017033377 ASHRAE STAFF SPECIAL PUBLICATIONS Mark S Owen, Editor/Group Manager of Handbook and Special Publications Cindy Sheffield Michaels, Managing Editor James Madison Walker, Managing Editor of Standards Lauren Ramsdell, Assistant Editor Mary Bolton, Editorial Assistant Michshell Phillips, Editorial Coordinator PUBLISHING SERVICES David Soltis, Group Manager of Publishing Services Jayne Jackson, Publication Traffic Administrator PUBLISHER W Stephen Comstock Updates and errata for this publication will be posted on the ASHRAE website at www.ashrae.org/publicationupdates CONTENTS Part I General Concepts Chapter Background Introduction Historical Notes Building Energy Use Conceptualizing an HVAC System Sustainability and Green Buildings Problems Bibliography Chapter Thermodynamics and Psychrometrics Fundamental Concepts and Principles 11 Properties of a Substance 13 Forms of Energy 36 First Law of Thermodynamics 40 Second Law of Thermodynamics 42 Third Law of Thermodynamics 44 Basic Equations of Thermodynamics 44 Thermodynamics Applied to Refrigeration 44 Applying Thermodynamics to Heat Pumps 49 Absorption Refrigeration Cycle 49 Problems 50 Bibliography 55 SI Tables and Figures 55 Chapter Basic HVAC System Calculations Applying Thermodynamics to HVAC Processes 67 Single-Path Systems 72 Air-Volume Equations for Single-Path Systems 72 Psychrometric Representation of Single-Path Systems 74 Sensible Heat Factor (Sensible Heat Ratio) 74 Problems 76 Bibliography 80 Chapter Design Conditions Indoor Design Conditions 81 Outdoor Design Conditions: Weather Data 88 Other Factors Affecting Design 140 Temperatures in Adjacent Unconditioned Spaces 140 Problems 141 Bibliography 142 SI Tables and Figures 143 Chapter Load Estimating Fundamentals General Considerations 145 Outdoor Air Load Components 145 Heat-Transfer Coefficients 156 Calculating Surface Temperatures 170 Problems 171 Contents vi Bibliography 177 SI Figures and Tables 179 Chapter Residential Cooling and Heating Load Calculations Background 191 General Guidelines 192 Cooling Load Methodology 197 Heating Load Methodology 200 Nomenclature 205 Load Calculation Example 207 Problems 209 Bibliography 212 SI Figures and Tables 214 Chapter Nonresidential Cooling and Heating Load Calculations Principles 221 Initial Design Considerations 225 Heat Gain Calculation Concepts 225 Description of Radiant Time Series (RTS) 252 Cooling Load Calculation Using RTS 255 Heating Load Calculations 258 Design Loads Calculation Example 262 Problems 274 Bibliography 276 SI Figures and Tables 281 Chapter Energy Estimating Methods General Considerations 297 Component Modeling and Loads 298 Overall Modeling Strategies 299 Integration of System Models 300 Degree-Day Methods 301 Bin Method (Heating and Cooling) 310 Problems 312 Bibliography 316 Chapter Duct and Pipe Sizing Duct Systems 317 Fans 354 Air-Diffusing Equipment 362 Pipe, Tube, and Fittings 364 Pumps 369 Problems 371 References 375 SI Figures and Tables 377 Chapter 10 Economic Analyses and Life-Cycle Costs Introduction 381 Owning Costs 381 Service Life 381 Depreciation 384 Interest or Discount Rate 384 Periodic Costs 384 Operating Costs 385 vii Principles of HVAC, 8th Edition Economic Analysis Techniques 389 Reference Equations 392 Problems 392 Symbols 393 References 394 Bibliography 394 Part II HVAC Systems Chapter 11 Air-Conditioning System Concepts System Objectives and Categories 397 System Selection and Design 398 Design Parameters 398 Performance Requirements 399 Focusing on System Options 399 Narrowing the Choice 400 Energy Considerations of Air Systems 401 Basic Central Air-Conditioning and Distribution System 402 Smoke Management 404 Components 404 Air Distribution 407 Space Heating 409 Primary Systems 409 Space Requirements 411 Problems 414 Bibliography 416 Chapter 12 System Configurations Introduction 417 Selecting the System 418 Multiple-Zone Control Systems 418 Ventilation and Dedicated Outdoor Air Systems (DOAS) 421 All-Air System with DOAS Unit 422 Air-and-Water Systems with DOAS Unit 422 In-Space Temperature Control Systems 423 Chilled-Beam Systems 425 Problems 429 Bibliography 432 Chapter 13 Hydronic Heating and Cooling System Design Introduction 433 Closed Water Systems 434 Design Considerations 442 Design Procedures 451 Problems 453 Bibliography 454 Chapter 14 Unitary and Room Air Conditioners Unitary Air Conditioners 455 Combined Unitary and Dedicated Outdoor Air Systems 457 Window Air Conditioners 457 Through-the-Wall Conditioner System 458 Typical Performance 459 Minisplits, Multisplits, and Variable-Refrigerant-Flow (VRF) Systems 459 Contents viii Water-Source Heat Pumps 460 Problems 461 Bibliography 461 Chapter 15 Panel Heating and Cooling Systems General 463 Types 464 Design Steps 466 Problems 467 Bibliography 467 Chapter 16 Heat Pump, Cogeneration, and Heat Recovery Systems General 469 Types of Heat Pumps 469 Heat Sources and Sinks 471 Cogeneration 474 Heat Recovery Terminology and Concepts 475 Heat Recovery Systems 477 Problems 480 Bibliography 480 SI Figures 481 Part III HVAC Equipment Chapter 17 Air-Processing Equipment Air-Handling Equipment 483 Cooling Coils 483 Heating Coils 488 Evaporative Air-Cooling Equipment 489 Air Washers 490 Dehumidification 490 Humidification 492 Sprayed Coil Humidifiers/Dehumidifiers 494 Air Cleaners 494 Air-to-Air Energy Recovery Equipment 499 Economizers 506 Problems 507 Bibliography 508 SI Table 509 Chapter 18 Refrigeration Equipment Mechanical Vapor Compression 511 Absorption Air-Conditioning and Refrigeration Equipment 529 Cooling Towers 536 Problems 537 Bibliography 539 SI Tables 540 Chapter 19 Heating Equipment Fuels and Combustion 543 Burners 546 Residential Furnaces 547 Commercial Furnaces 549 Boilers 552 ix Principles of HVAC, 8th Edition Terminal Units 554 Electric Heating 555 Problems 557 Bibliography 558 Chapter 20 Heat Exchange Equipment Modes of Heat Transfer 561 Heat Exchangers 567 Basic Heat Exchanger Design Equation 569 Estimation of Heat Load 569 Mean Temperature Difference 569 Estimation of the Overall Heat Transfer Coefficient U 570 Extended Surfaces, Fin Efficiency, and Fin-Tube Contact Resistance 571 Fouling Factors 572 Convective Heat Transfer Coefficients hi and ho 573 Calculation of Heat Exchanger Surface Area and Overall Size 576 Fluids and Their Thermophysical Properties 576 Example Finned-Tube Heat Exchanger Design 576 Problems 576 Bibliography 578 Appendices Appendix A SI for HVAC&R General 579 Units 579 Symbols 580 Prefixes 581 Numbers 581 Words 582 Appendix B Systems Design Problems Combination Water Chillers 585 Absorption Chiller Selection 585 Owning and Operating Costs 586 Animal Rooms 586 Greenhouse 588 Drying Room 589 Air Washer 589 Two-Story Building 589 Motel 590 Building Renovation 590 Building with Neutral Deck Multizone 591 Index 593 This book includes access to a website containing the Radiant Time Series (RTS) Method Load Calculation Spreadsheets See www.ashrae.org/PHVAC8 Appendix A | SI for HVAC&R 581 PHYSICAL PROPERTIES 6.7 When compound units are formed by multiplication, leave a space between units that are multiplied Examples: newton metre, not newton-metre; volt ampere, not volt-ampere 6.8 Use the modifier squared or cubed after the unit name Atmospheric Pressure Standard pressure = 101.325 kPa, exact value by definition (approximately 29.921 in Hg at 32°F; 760 mm Hg at 0°C; 14.696 psi at 32°F) Example: metre per second squared Gravity Exception: For area or volume, place the modifier before the units Example: square millimetre; cubic metre Standard acceleration = 9.806 65 m/s2, exact value by definition (approximately 32.1740 ft/s2) 6.9 When compound units are formed by division, use the word per, not a solidus ( / ) Examples: metre per second, not metre/second; watt per square metre, not watt/square metre Standard Air Dry air at 101.325 kPa and 20°C (density  1.204 kg/m3) Specific heat (constant pressure), cp = 1.006 kJ/(kg·K) Heating of Air TEMPERATURE CONVERSION Sensible heat qs = 1.2 Qt Latent heat ql = 3.0 Qw Total heat qt = 1.2 Qh (exact) tC = (tF  32)/1.8 tF = 1.8 tC + 32 tC = T  273.15 tF = TR  459.67 T = TR/1.8 TR = 1.8T T = tC + 273.15 TR = tF + 459.67 where tC T tF TR and = = = = Celsius temperature, °C thermodynamic (absolute) temperature, kelvins (K) Fahrenheit temperature, °F thermodynamic (absolute) temperature, degrees Rankine (°R) °C = K = 1.8°F°F = °R = °C/1.8 where t = temperature difference, K or °C w = moisture content difference, g/kg (dry air) h = enthalpy difference, kJ/kg (dry air) Q = volume flow rate, m3/s (standard air) qs, ql, qt = heat flow, kW Water Heat of vaporization at 101.325 kPa and 100°C = 2257 kJ/kg Heat of fusion at 0°C = 334 kJ/kg 582 Principles of HVAC, 8th Edition CONVERSION FACTORS When making conversions, remember that a converted value is no more precise than the original value Round off the final value to the same number of significant figures as those in the original value CAUTION: The conversion values are rounded to three or four significant figures, which is sufficiently accurate for most applications See ANSI SI 10 for additional conversions with more significant figures Multiply acre atmosphere, standard bar barrel (42 US gal, petroleum) Btu, (International Table) Btu/ft2 Btu·ft/h·ft2 ·°F Btu·in/h·ft2 ·°F (thermal conductivity, k) Btu/h Btu/h·ft Btu/h·ft2 Btu/h·ft2 ·°F (heat transfer coefficient, U) Btu/lb Btu/lb·°F (specific heat, cp) bushel calorie, (thermochemical) calorie, nutrition (kilocalorie) candle, candlepower centipoise, dynamic vicosity,  centistokes, kinematic viscosity,  clo dyne/cm2 EDR hot water (150 Btu/h) EDR steam (240 Btu/h) fuel cost comparison at 100% eff cents per gallon (no fuel oil) cents per gallon (no fuel oil) cents per gallon (propane) cent per kWh cents per therm ft ft ft/min, fpm ft/s, fps ft of water ft of water per 100 ft of pipe ft2 ft2 ·h·°F/Btu (thermal resistance, R) ft2 /s, kinematic viscosity,  ft3 ft3 ft3/h, cfh ft3/min, cfm ft3/s, cfs footcandle ft·lbf (torque or moment) ft·lbf (work) ft·lbf/lb (specific energy) ft·lbf/min (power) gallon, US (*231 in3) gph gpm gpm/ft2 gpm/ton refrigeration grain (1/7000 lb) gr/gal horsepower (boiler)(33,470 Btu/h) horsepower (550 ft·lbf/s) inch inch of mercury (60°F) inch of water (60°F) To Obtain Multiply in/100 ft (thermal expansion) in·lbf (torque or moment) in2 in3 (volume) in3/min (SCIM) in3 (section modulus) in4 (section moment) km/h kWh kW/1000 cfm kilopond (kg force) kip (1000 lbf) kip/in2 (ksi) litre MBtuh (1000 Btu/h) met micron (m) of mercury (60°F) mil (0.001 in.) mile mile, nautical mph mph millibar mm of mercury (60°F) mm of water (60°F) ounce (mass, avoirdupois) ounce (force of thrust) ounce (liquid, US) ounce (avoirdupois) per gallon perm (permeance) perm inch (permeability) pint (liquid, US) pound lb (mass) lb (mass) lbf (force or thrust) lb/ft (uniform load) lbm/(ft·h) (dynamic viscosity, ) lbm/(ft·s) (dynamic viscosity, ) lbf ·s/ft2 (dynamic viscosity, ) lb/min lb/h lb/h (steam at 212°F)(970 Btu/h) lbf/ft2 lb/ft2 lb/ft3 (density, ) lb/gallon ppm (by mass) psi quad (1015 Btu) quart (liquid, US) revolutions per minute (rpm) square (100 ft2 ) tablespoon (approx.) teaspoon (approx.) therm (100,000 Btu) ton, short (2000 lb) ton, refrigeration (12,000 Btu/h) torr (1 mm Hg at 0°C) watt per square foot yd yd2 yd3 To Obtain By 0.4047 *101.325 *100 159 1.055 11.36 1.731 To Obtain kPa kPa L kJ kJ/m2 W/(m·K) 0.1442 0.2931 0.9615 3.155 W/(m·K) W W/m W/m2 5.678 *2.326 4.184 0.03524 *4.184 *4.184 *1.0 *1.00 *1.00 0.155 *0.100 44.0 70.3 W/(m2 ·K) kJ/kg kJ/(kg·K) m3 J kJ cd mPa·s mm2/s m2 ·K/W Pa W W 0.0677 0.0632 0.113 2.78 0.0948 *0.3048 *304.8 *0.00508 *0.3048 2.99 0.0981 0.09290 0.176 92 900 28.32 0.02832 7.866 0.4719 28.32 10.76 1.36 1.36 2.99 0.0226 3.785 1.05 0.0631 0.6791 0.0179 0.0648 17.1 9.81 0.746 *25.4 3.377 248.8 $/GJ $/GJ $/GJ $/GJ $/GJ m mm m/s m/s kPa kPa/m m2 m2 ·K/W mm2/s L m3 mL/s L/s L/s lx N·m J J/kg W L mL/s L/s L/(s·m2) mL/J g g/m3 kW kW mm kPa Pa By Divide Note: In this list the kelvin (K) expresses temperature intervals The degree Celsius symbol (°C) is often used for this purpose as well *Conversion factor is exact By 0.833 113 645 16.4 0.273 16 400 416 200 0.278 *3.60 2.12 9.81 4.45 6.895 *0.001 0.2931 58.15 133 *25.4 1.61 1.85 1.61 0.447 *0.100 0.133 9.80 28.35 0.278 29.6 7.49 57.45 1.46 473 0.4536 453.6 4.45 1.49 0.413 1490 47 880 0.00756 0.126 0.284 47.9 4.88 16.0 120 *1.00 6.895 1.06 0.946 *1/60 9.29 15 105.5 0.907 3.517 133 10.8 *0.9144 0.836 0.7646 By To Obtain mm/m mN·m mm2 mL mL/s mm3 mm4 m/s MJ kJ/m3 N kN MPa m3 kW W/m2 mPa mm km km km/h m/s kPa kPa Pa g N mL kg/m3 ng/(s·m2 ·Pa) ng/(s·m·Pa) mL kg g N kg/m mPa·s mPa·s mPa·s kg/s g/s kW Pa kg/m2 kg/m3 kg/m3 mg/kg kPa EJ L Hz m2 mL mL MJ Mg; t (tonne) kW Pa W/m2 m m2 m3 Divide Appendix B SYSTEMS DESIGN PROBLEMS B.1 Combination Water Chillers (Centrifugal and Absorption Machines in Series) Given: The 1000 ton turbine-driven centrifugal compressor in the figure below is supplied with steam at 30,000 lb/h at 125 psig The turbine exhaust pressure is 15 psig The temperature rise through the condenser is 10°F A 1500 ton lithium bromide water chiller uses exhaust steam at 12 psig from the steam turbine It has a 4-pass evaporator with a pressure drop of 15 ft The leaving temperature for the 4800 gpm condenser water is 105.3°F Water velocity for the condenser and chilled-water piping is limited to 10 ft/s Chilled-water supply temperature is 40°; chilled-water return temperature is 52°F Cooling tower design data: 95°F dry bulb, 76°F wet bulb, 9°F approach Required: Calculate the overall steam rate in pounds per hour per ton for the refrigeration plant Calculate the chilled-water flow rate in gpm What is the temperature of water off the tower? What is the temperature of the water entering the cooling tower? In the evaporator of the centrifugal compressor, what is the pressure drop and water velocity in the tubes? In the condenser of the centrifugal compressor, what is the pressure drop and water velocity in the tubes? Using Schedule 40 pipe, what size pipe would you use for the condenser water piping to each machine (a,b), the cooling tower (c), and the chilled-water piping (d)? B.2 Absorption Chiller Selection A small college is to be built in the Santa Fe, New Mexico, area (elevation 7000 ft) You have the assignment to design 584 Principles of HVAC, 8th Edition the mechanical systems for this project You decide to recommend a central plant for both heating (steam) and cooling (chilled water) Since the available fuel is relatively inexpensive, you decide to use absorption refrigeration to keep the electrical demand as low as possible and to make use of the steam boilers that would otherwise be idle in the summertime Your preliminary analysis indicates that the first four buildings to be built will have the following characteristics: Building A B C D Area, ft2 75,000 50,000 65,000 25,000 Estimated ft2/ton 400 325 350 300 Estimated Total Tons 190 150 185 85 In addition, you decide to install sufficient additional capacity to handle 100,000 ft2 of building (you not know exactly what type of building it will be, so average and estimate) Also estimate a 5% loss in capacity in the piping and distribution system Steam is available at 30 psi and can be reduced to any pressure you desire You decide to have 42°F to 58°F or a 16°F temperature difference (TD0 as your chilled-water design temperatures Condensing water is available from the cooling tower at 80°F The maximum allowable pressure drop through the chiller is 40 ft for the condenser-absorber and 20 ft for the evaporator You want at least a 0.001 fouling factor on the condenser and a 0.0005 factor on the evaporator A Select and specify an absorption chiller to handle the determined capacity Indicate water and steam flow rates and unit pump motor horsepower requirements B What is the rate of refrigerant flow at maximum load? C What is the theoretical pump horsepower required for the chilled water and condensing water due to the pressure drop through the unit? D What is the total hourly purchased energy requirement for this chiller (electrical + thermal)? How does this compare with an equivalent motor-driven centrifugal machine? Which one is more economical to operate (assume electricity costs five times as much as steam)? E What is the cooling tower requirement for the absorption machine compared with a centrifugal machine? How might this affect your answer to question D above? B.3 Owning and Operating Costs Management has decided to move a subsidiary of your company to Indianapolis, Indiana This will necessitate a new office building The chief engineer was asked to estimate the owning and operating cost for the refrigeration and summer air-conditioning services in the building The chief just called you in this morning and now it is your estimate Here is all the information available Building: Five-story, 160 ft by 300 ft gross with 90% of floor area air conditioned Refrigeration: reciprocating compressors, R-134a, 95°F condensing temperature, 40°F evaporator temperature Power rate: $0.09 per kWh Includes both demand and energy charge Water rate: $1.00 per 1000 gal Water rate for condenser: 3.0 gpm per ton for full load operating hour Operating hours for auxiliaries: 1/2 days per week Power requirements: Fan, air: 0.4 bhp per 1000 cfm Fan, cooling tower: 0.05 bhp per ton Pump, chilled water: 1.10 bhp per ton Pump, cooling tower: 0.09 bhp per ton Annual operating labor and maintenance: 1/2% of first cost (average for life of equipment) Interest: 5% Taxes: $2.50 per $100 of assessed valuation Assessed valuation: 25% of first cost B.4 Animal Rooms Facilities are to house laboratory animals at control temperature, humidity, air motion, odor, and bacterial count Design conditions vary widely depending on whether the animals are subjected to test environments or simply quartered A general range of design temperatures and relateve humidity is tabulated in Table Recommended tolerances are +2°F dry bulb and ±5% rh at the point of control Low temperature gradients are desirable The maximum spread vertically and horizontally within the cage zones should be limited to within ±1.5°F of the control point Air motion limits in the cage zone are 35 to 50 fpm for general applications and 25 to 35 fpm in quarters for mice See the diagram on the following page The approximate amount of heat released by laboratory animals at rest and during normal activity is shown in Table Conformance to temperature and humidity requirements requires control on a room basis and preferably on a module basis, because cage loading, occupancy distribution, and animal heat release are variable A module constitutes two rows of cages with a working aisle separation Temperature and velocity gradient control requires low supply air to room air temperature differential, overhead high induction diffusion, uniform horizontal and vertical air distribution, and low return outlets Odor control within animal rooms requires 100% outdoor air for odor removal from recirculated air Unidirectional single pass airflow through the room is an aid for lowering odor levels Air rates range from 10 to 20 air changes per hour depending on the animal occupancy and density Appendix B | Systems Design Problems 585 586 Principles of HVAC, 8th Edition Table B-1 Animal Room Temperature Animal Mice Rats Guinea Pigs Rabbits Cats Dogs Monkeys Temp., °F 73 to 77 73 to 77 72 to 74 70 to 72 75 to 77 70 to 72 76 to 79 Relative Humidity, % 45 to 50 45 to 50 45 to 50 45 to 50 45 to 50 45 to 50 75 Table B-2 Heat Generated by Laboratory Animals Heat Generation, Btu/h per Animal Animal Mouse Hamster Pigeon Rat Guinea Pig Chicken Rabbit Cat Monkey Dog Goat Sheep Pig Mass, g 21 118 275 300 410 2,100 2,600 3,000 4,200 16,000 36,000 45,000 250,000 Table B-3 Animal Mice Rats Guinea pigs Chickens Rabbits Cats Monkeys Dogs Response (Basal) Total Heat 0.6 1.65 4.63 4.46 5.80 18.8 19.3 25.1 34.5 87.5 137.0 192.0 718.0 Normally Active (est.) Sensible Latent Total 3.3 1.7 5.0 10 13 15 18 22 11 33 32 64 61 75 15 12 18 25 47 76 79 100 92 250 410 560 2100 46 120 130 190 700 138 370 540 750 2800 Average Odor-Free Requirements Mass, g 21 200 410 2,100 2,600 3,000 3,200 14,000 Gross Space ft3/animal 1.0 3.5 6.0 8.0 10.0 35.0 100.0 150.0 Odor-Free Air cfm/animal 0.10 0.75 1.5 2.0 2.0 8.0 20.0 50.0 Odor-free air rates for various animal occupancies are listed in Table Control of odor dissemination to adjoining spaces requires that the animal room be maintained under negative pressure or that air locks be employed Bacterial control require high-efficiency filtration or germicidal treatment Conditions in animal rooms must be continuously maintained, which requires year-round availability of refrigeration and, in some cases, dual air-conditioning facilities and emergency power for motor drives and control instrument energy An air-conditioning system is to be designed for an animal room for housing laboratory animals The area is a separate wing of a research facility and is to have its own completely independent system to provide year-round temperature and humidity control The large animal room will have a maximum of 80 dogs or their equivalent and the small animal room will contain mice, rats, rabbits and a few monkeys, with an equivalent heat release of 200 rabbits Insulation and window construction shall be selected as follows: Design Temperature +30 °F and above +10 °F to +30°F −20 °F to +10°F below −20 °F Insulation None in in in Windows (all sealed) Single pane Single pane Two pane Two pane U for single pane = 1.13 Btu/h·ft2 · °F U for double pane = 0.45 Btu/h·ft2 · °F Lights: In animal rooms: W/ft2 In feed room: W/ft2 (fluorescent) In laboratory: W/ft2 For laboratory: bunsen burners, one 1100 W sterilizer For feed room: hp electric food grinder Perform the following: (a) Calculate the heating loads for each room (b) Calculate the cooling loads for each room (c) Calculate the air quantities (cfm) for each room Make a schematic diagram of the apparatus required for air conditioning (Heat air with hot water from hot water boiler) (d) Calculate the areas of the cooling coil required and the face area (frontal area) (e) Make a single line duct layout Size the ducts Select the grilles, diffusers, and other components (f) Select filter pressure loss Calculate pressure losses in other parts of the air distributing system, coils, and outdoor louvers Calculate the total pressure loss Select fan, fans or units (g) Select a refrigeration water chilling unit or units Select a hot water boiler Select pump or pumps for chilled water circulation (h) Draw a plan of the building on 22 in × 17 in paper (1/2 in = ft in.) Draw the mechanical system designed on the plan (Make sure mechanical system outline is heavier than building outline.) Draw a plan and elevation of equipment room showing main items of equipment and ducts (1/2 in = ft, in.) B.5 Greenhouse An environmental control system is to be developed for a greenhouse located in the Lafayette, Indiana, area This greenhouse is a rigid frame structure, 40 ft wide and 100 ft long, with a roof slope of 6/12 and a sidewall height of ft The covering material is a single layer of polyethylene plastic Appendix B | Systems Design Problems 587 Determine the following, listing your sources of data and assumptions used: will give more intimate contact between air and product and perhaps the same air volume flow rate can be used What is the maximum heat requirement for the house in Btu/h if the inside temperature is not to fall below 60°F? On a clear winter day, January 21, with an outside noon temperature of 30°F and 65% rh, how much heat (Btu/h) or ventilation (cfm) is required to maintain an inside temperature somewhere between 60 and 70°F at 12 noon solar time? (Consider sensible heat only.) Reconsider Part assuming that half of the solar radiation load is used to evaporate water from the plants, soil, and floor and manifests itself as a latent heat load A further restriction of a maximum 50% inside rh is added to prevent condensation on the inside of the plastic covering Under these conditions, what is the amount of heat (Btu/h) and/or ventilation (cfm) required to maintain an inside temperature of 75°F? On a clear summer day, July 21, with an outside noon temperature of 85° and 50% rh, what is the minimum ventilation rate (cfm) required to prevent the inside temperature from exceeding 90°F? (Consider sensible heat only.) A pad evaporative cooler is to be considered for cooling the greenhouse on a clear day, August 21, with a noon temperature of 90°F and 40% rh The entering air, after passing through the pad, has 90% rh Using the ventilation rate from Part 4, what is the exhaust air temperature? How many square feet of pad are required if the velocity through the pad is restricted to 150 fpm? (c) What will be the humidity ratio of the air leaving the drying room for a 20% moisture content of the product? (You retain the 10 air changes per hour and the 112°F dry-bulb leaving air.) B.6 Drying Room You are making a feasibility study for a 90,000 ft3 drying room built inside a factory An air conditioner is located outside the drying room Air enters the conditioner from the plant at 82°F dry bulb, 50% rh, and is distributed to the drying room at 82°F dry bulb, 10% rh The air leaves the drying room at 112°F dry bulb, 90% rh and is exhausted from the factory through an exhaust system Product passes through the drying room on a belt conveyor entering at 3600 lb/h at 128°F dry bulb, 40% moisture content Assume 10 air changes per hour through the drying room Assume no heat or moisture flow through the drying room structure (a) What is the refrigeration load on the conditioning apparatus in tons? (b) What is the moisture content of the product leaving the drying room? You report the results to the product engineer who wants to know if you can dry the product to 20% moisture The engineer says the 112°F leaving air is maximum; otherwise; the product will be too hot and will have to be cooled after it leaves the drying room to prevent checking You study the conveyor and feel it will be possible to modify the air distribution arrangement in the drying room This B.7 Air Washer A chiller supplies water to a washer The water leaves the chiller at 44°F and is returned at 54°F Design conditions in the building are 78°F dry bulb and 64.5°F wet bulb A mixture of outdoor and recirculated air enters the washer at 88°F dry bulb and 72°F wet bulb The total air circulated is 33,000 cfm The washer has a performance factor of 0.85 The washer is a two-bank single-stage design What is the refrigeration load on the chiller? What water quantity should it be handling in gpm? What room SHR will these operating conditions exactly satisfty? How many nozzles would you expect to find in the washer assuming gpm per nozzle? What should be the cross-sectional area of the washer assuming a velocity of 500 fpm? Suppose the design engineer made a mistake in estimating the head on the chilled water circulating pump The operating head was lower than the selection point for the pump From the characteristic pump curve you estimate, the pump is now delivering 30% more water than in Part Assuming the same performance factor, load, and air flow, what is your answer to Part 3? Discuss the effect of the conditions in the building B.8 Two-Story Building As both architect and chief mechanical engineer of your own consulting engineering firm, you are responsible for the design of the building and for the sizing and selection of the major components of the HVAC system for the building A report on your design, analysis, and recommendations for the HVAC system must be prepared for the sponsor and his staff Sizing and selection are to cover only the heating, cooling, and humidifying equipment with cost estimates Estimates of annual HVAC energy use and cost are to be included Simple tables of design conditions, building data, results, and recommended equipment should be included in the body of report A cover letter is mandatory Completely labeled sketches and diagrams should be included as appropriate Detailed calculations and/or computer printouts are to be included as appended material The 24,000 ft2, two-floor office building is to be located in Louisville, Kentucky There are to be six, separately thermostated zones, three on each floor The east and north ends are the be combined into one zone, the west and south into a second, and a center portion into the third The zones are each approximately the same size The east and north zones are to 588 contain a minimum of 70% glass in the exterior walls while the exterior walls of the west and south zones are to contain between 20 and 40% glass Since the owner will be picking up the utility bills, he or she is somewhat energy conscious However, the owner is also very concerned about the first cost of the building and does not plan extreme departures from common building practices and materials A rooftop installation is planned to conserve interior space As the engineer and architect hired by the owner-to-be of the building, you are to design the building, specifying the layout, wall and ceiling descriptions, types of glass, doors, etc Neglect details such as closets, room dividers, halls, etc Items to be determined include: Design heating load for each space Design cooling load for each space Projected energy requirements for heating and for cooling Sizing of major components (heating unit, cooling unit, fan, humidifier) Sizing and layout of ducts Specific recommendations for equipment and fuels Estimated initial cost of HVAC equipment and annual operating cost B.9 Motel As both architect and chief mechanical engineer of your own consulting engineering firm, you are responsible for the design of the building and for the sizing and selection of the major components of the HVAC system for the building A report on your design, analysis, and recommendations for the HVAC system must be prepared for the sponsor and his staff Sizing and selection are to cover only the heating, cooling, and humidifying equipment with cost estimates Estimates of annual HVAC energy use and cost are to be included Simple tables of design conditions, building data, results and recommended equipment should be included in the body of the report A cover letter is mandatory Completely labeled sketches and diagrams should be included as appropriate Detailed calculations are to be included as appended material The 24-unit (plus office) single building motel is to be located in St Louis, Missouri, in the Lambert Airport area Each unit is to be 12 ft by 24 ft with the office twice the size of a regular room Two-thirds of the units are to be nonsmoking Each unit will be conditioned with its own packaged terminal air conditioner (PTAC) or packaged terminal heat pump (PTHP) Since the owner will be picking up the utility bills, he or she is somewhat energy conscious However, the owner is also very concerned about the first cost of the building and does not plan extreme departures from common building practices and materials As the engineer and architect hired by the owner-to-be of the building, you are to design the building, specifying the layout, wall and ceiling descriptions, types of glass, doors, etc Items to be determined include: Principles of HVAC, 8th Edition Design heating load for each space Design cooling load for each space Projected energy requirements for heating and for cooling Sizing of major components (heating unit, cooling unit, fan, humidifier) Specific recommendations for equipment and fuels Estimated initial cost of HVAC equipment and annual operating cost B.10 Building Renovation As chief mechanical engineer of a consulting engineering firm, you are responsible for the design, sizing, and selection of the major components of the HVAC system for the building A report on your design, analysis, and recommendations for the HVAC system must be prepared for the sponsor and his staff Sizing and selection are to cover the heating, cooling, and humidifying equipment with cost estimates Estimates of annual HVAC energy use, both before and after the modifications, are to be included Simple tables of design conditions, building data, results, and recommended equipment should be included in the body of report A cover letter is mandatory Completely labeled sketches and diagrams should be included as appropriate Detailed calculations and/or computer printouts are to be included as appended material The project concerns the complete renovation of an office building located in St Louis, Missouri, and shown in the following sketch Sketch of Project 10 Building Appendix B | Systems Design Problems The building is divided into 16 separately thermostated zones Physical description and building operation (base case) data are Building roof area: 22,810 ft2 Building floor area: 45,620 ft2 Ceiling height: 8.5 ft Building exterior wall area: 9,460 ft2 (net) Building glass area: 7,536 ft2 Building thermal mass: M (medium) Uniform internal load density: 2.9 W/ft2 Occupancy: 408 people (uniformly distributed) Original U-factors: Roof—0.23 Btu/h·ft2 ·°F Walls—0.18 Btu/h·ft2 ·°F Glass—0.8 Btu/h·ft2 ·°F Shading coefficient for glass: 0.5 Originally built in the late 1960s with an all-electric reheat HVAC system, the renovated building will replace the inefficient reheat system with all-electric packaged terminal air conditioners (PTACs) in each space In the exterior zones, the PTACs will include provisions for ventilation air For the interior zones, the PTACs will operate without outdoor air provisions and a separate rooftop makeup air system will be used for ventilation requirements When renovated, all walls and ceilings will include an additional inches of glass fiber, organic bonded rigid insulation, The windows will be upgraded to double pane, 1/4 in air gap, aluminum frame with thermal break (nonoperable) The internal load density is estimated to have increased over the years from the original 2.9 W/ft2 to 6.0 W/ft2 Include the following items: 589 air energy recovery equipment, and pumps Piping, ducting, and related fittings need not be sized nor selected at this time Simple tables of design conditions, building data, results and recommended equipment should be included in the body of the report A cover letter is mandatory Completely labeled sketches and diagrams should be included as appropriate Detailed calculations and appropriate manufacturers’ catalog data are to be included as appended material Building Location: Atlanta, GA The ventilation requirements are to be in accordance with ASHRAE Standard 62 Anticipate occupany rate is 10 persons per 1000 ft2 of floor space Design pressure drop for the ducting system is 3.25 in of water The design loads are given in the following table Design Loads (Btu) Zone Heating (sensible) Cooling (sensible) Cooling (latent) −95,000 164,000 47,000 +33,000 157,000 14,000 −98,000 199,000 40,000 −276,000 567,000 72,000 The winter latent load is negligible Type of HVAC System: Multizone with neutral deck Primary Systems: R-22 condensing unit and DX coil, multiple gas-fired boilers for steam coil Auxiliary Equipment: Spray washer, heat pipe air-to-air energy recovery system, air-side economizer Design heating load for each space Design cooling load for each space Projected annual energy requirements for heating and for cooling Sizing and selection of major components Sizing and layout of ducts for interior zones Estimated initial cost of HVAC equipment and annual operating cost Potential problem areas with this type of equipment B.11 Building with Neutral Deck Multizone As the chief mechanical engineer of your own consulting engineering firm, you are responsible for preliminary design of the HVAC system for the building shown in the figure at right Selection of all major components is to be included A report on your analysis and recommendations for the HVAC system must be prepared for the sponsor and his staff Sizing and selection will cover all heat exchangers (coils), fans, refrigeration units, boilers and/or other heating equipment, humidifiers, cooling towers, heat reclaim and/or air-to- Sketch for Project 11 INDEX A B absorption equipment 489–490, 532 absorption refrigeration 22, 49, 53, 509, 527, 584 adiabatic mixing 36, 38, 69, 70 saturation process 30 adjacent unconditioned spaces 140 AFUE 301, 308, 547 air cleaners 5, 401, 492, 494–495, 497 contaminants 2, 145 distribution 81, 154, 157, 195, 296, 355, 359–360, 362, 380, 399, 401, 405, 407, 418, 454–455, 584, 587 handling equipment 296, 409, 481, 482 leakage 88, 146–148, 150–152, 159, 171, 189, 192–194, 208, 219, 250 moving 8, 70 quality 1, 5, 7, 74, 84, 146–147, 151– 154, 194, 395, 401, 419, 492 ventilation 73, 136, 156 air conditioner 4–5, 48, 74, 78, 302, 312, 314, 355, 382, 412–413, 415, 421, 453, 455– 456, 467, 481–483, 525, 587–589 air distribution 81, 154, 156–157, 195, 296, 355, 359–360, 362, 380, 399, 402, 405, 407, 418, 454–455, 584, 587 air leakage 147, 163, 181, 498, 507 air washer 4, 323, 382, 485, 487–488, 490, 492, 505, 580, 587 air-and-water system 398, 420 air-conditioning components 397 air-conditioning equipment 1, 5, 148, 171, 410, 453 air-conditioning system xi, 1–2, 4, 6, 8, 51, 67, 81, 140, 156, 189, 210, 219, 223, 250, 252, 310, 315, 322, 358, 360, 369, 379, 395, 397, 400, 402, 407–409, 414, 419, 453, 483, 515, 572, 586 air-heated floor 462–463 air-volume equation 72 antifreeze 431, 451, 473, 486 antifreeze solution 404, 450, 469 aqua-ammonia 22 aqua-ammonia enthalpy-concentration diagram 22, 26, 63 ASHRAE history 2–5 Standard 34 527, 529, 531 Standard 51 353, 373 Standard 52 404 Standard 55 81, 82, 84, 86, 140, 191, 200 Standard 62 146–147, 151, 153–154, 156, 189, 194, 395, 401, 407, 410, 419– 420, 589 Standard 68 406 Standard 90 234, 241, 417 Standard 90.1 6, 8, 140, 405 Standard 103 547 Standard 169 121 ASHRAE atmospheric data 36, 55 basements, heat loss from 136, 192, 194, 200–201, 207 bin method 296, 299, 308, 310 boiler 1–5, 219, 232, 272, 296, 308, 366–368, 371–372, 380, 382, 385, 407–412, 428, 431–434, 441–443, 446–447, 449–451, 459, 467, 472–474, 478, 492, 498, 544, 545, 550–552, 554, 556, 580, 582, 584, 586, 589 buffer spaces 189, 192, 194, 199, 202, 214 building use 121, 154, 295 burner 247, 292, 382, 472, 542–545, 547– 548, 550, 586 burners 246 C capillary tube 456, 482, 525–526 capital recovery factor 388, 391 Carrier, Willis 4–5, 416 chiller 1–2, 5, 7–8, 136, 156, 219, 296–297, 308, 380–382, 386, 389–391, 407–409, 411, 422, 428–429, 431, 434, 437, 439, 441, 444–447, 450, 452–453, 467, 469, 472, 477–478, 498, 517, 525, 532, 534– 535, 567, 571, 580, 583–584, 587 circular 317 clothing insulation value 84–85 Coefficient 227, 230, 232, 280 coefficient 145, 174, 219, 223, 225–226 heat transfer 8, 141, 156, 172, 199, 220, 223, 225, 252, 271, 433, 443, 505, 520, 526–528, 560–561, 565, 568–569, 572, 573–574 shading 196, 230, 589 thermal resistance 159, 168, 172, 176, 202, 582 cogeneration 6, 296, 407, 467, 472, 478 coil application range 483 construction 481–482 cooling 7, 36, 71–72, 74, 79, 140, 219– 220, 237, 249–250, 298–299, 322, 368, 385, 398–399, 402, 404, 411–413, 417, 420, 423–424, 427–430, 433, 447, 449, 452, 455, 457, 462, 481–484, 488, 492, 498, 504, 506, 547–548, 566, 569, 574, 586 energy recovery loop 499–501 heating 74, 323, 399, 404, 407, 412– 413, 417, 419–421, 428–429, 433, 444, 450, 456, 459, 462–463, 481, 480–487, 492, 498, 505, 545, 556, 559, 566, 575 combustion 2–3, 29, 39, 154, 243, 381, 408, 410, 431, 434, 472, 495, 541–545, 547– 548, 550–551, 555 comfort thermal 81–85, 146, 295, 395 comfort condition 3, 85–86, 395–396, 413, 417, 445, 455, 502–503 comfort zone 84–86, 143 commercial furnace 547–548 compressor centrifugal 407–408, 477, 509, 517, 526, 583 reciprocating 3–4, 382, 408, 509–511, 584 rotary 5, 408, 512–513, 517 screw 513–515, 526 conceptualizing condenser 45–47, 49–50, 52–53, 297, 368, 372, 380, 382, 408–410, 412, 423, 434, 453, 455–459, 467, 469, 471–472, 475– 477, 482, 487, 501, 504, 509, 519–522, 525–526, 532–533, 535, 537, 540, 567, 571–572, 575, 583–584 conditioning conduction time series 251–253, 255–257, 263, 266 conservation of mass 13, 42, 67, 560 continuity equation 13, 69 convective and radiant percentages 254 convector 3, 366–367, 371, 412, 421–422, 432–433, 443, 552–554 cooler liquid 525, 528 cooling coil 7, 36, 71, 74, 79, 140, 219–220, 237, 250 cooling load 1, 2, 72, 136, 145, 159, 169, 172, 189–192, 195–198, 203, 206–207, 210, 212, 216, 220–223, 225, 234, 237–238, 243, 249–250, 253, 256, 260, 262–264, 266–271, 273–274, 298, 300, 302, 308, 310, 312, 314, 368, 395–398, 400, 412, 414, 422–423, 430, 433, 454, 457, 462, 469–470, 474, 477–478, 505–506, 519, 547–548, 586, 588–589 appliances 241, 243–244 temperature difference 222, 255, 308 cooling load methodology 195 cooling method 189–190 cooling method, degree-day 300, 302, 308 Cooling tower 409, 570 cooling tower 136, 296, 368, 380, 382, 385, 389, 408, 410, 416, 432, 458, 467, 470, 477, 487–488, 504, 509, 522, 534–535, 537, 571, 580, 583–584, 589 costs 2, 6, 7, 296–298, 302, 310, 312, 314, 322–323, 365, 379–391, 398, 402, 407, 409–410, 416, 436, 440, 443, 449, 461, 470–472, 473, 478, 497, 499, 504, 547, 556 D damper 7, 72, 74, 148, 194, 296, 298, 301, 322–323, 342, 344–345, 358–359, 369–372, 380, 382, 399, 402–405, 407, 417, 419–420, 449, 467, 473, 481, 486, 492, 504, 507, 518, 544, 547 dampers 403, 409, 412 degree day energy estimating methods 295 degree-day 89 data for various locations 137–139, 308 energy estimating methods 121, 295, 299–302, 310, 314 592 degree-day, variable-base heating 302 dehumidification 72, 76, 80, 88–89, 121, 136, 145, 147, 189, 197, 395, 404, 412–413, 420, 433, 444, 456–457, 461–462, 471, 483, 488–490 desiccant 136, 489–490, 499 design criteria for various occupancies 86–87 hydronic system 368, 431–432, 436–438, 440–442, 447, 450, 462, 552, 556 design condition metabolic rate 83–84 design conditions 1–2, 5, 71, 81, 83, 87–89, 121– 136, 140, 142, 148, 152, 156, 176, 191– 192, 199–200, 202, 2046–205, 223, 266, 270, 296–297, 302, 313, 395, 406, 424, 436, 443, 475, 488, 501–502, 506, 547, 584, 587–589 indoor 81, 171, 200, 223, 262 moisture and humidity 86 outdoor 71, 88, 156, 191, 223, 424 design criteria 2, 136, 381, 401 design hydronic system 451 design problems 583 diffuser 4, 219, 230, 315, 349–351, 360, 362, 367, 371, 380, 386, 397, 405, 418, 461– 462, 517, 519, 580, 586 door 148, 150, 152–153, 169–170, 176, 187, 195, 202, 206, 552 dry-bulb temperature 136, 475, 487, 497 dual-duct system 5, 417 dual-stream system 418 duct circular equivalent of rectangular 317 design procedures 322, 324 design velocities 322–323 fitting loss coefficient 320, 324–325 friction chart 317, 321 system characteristics 358 systems 194, 250 duct systems 250, 405 Ductwork 382 ductwork 72, 250, 296, 316, 320, 322–323, 349– 350, 353, 355, 357–358, 399, 401, 403– 406, 410–411, 416–417, 421, 453, 456, 491, 498, 544–545, 548 E economics 7, 379, 383–384, 398, 402, 407, 434, 436, 440, 443, 445, 497 economizer 146, 298–299, 402–403, 417, 455, 473, 475, 504–505, 534, 567 efficiency steady-state 300, 547 utilization 301, 547 electric heating 5, 310, 408, 419, 462, 463–464, 481, 486, 551, 553–554 energy 385 building use 5, 7, 295, 297 costs 297, 302, 310, 398, 407, 436, 504 forms 5, 295 recovery 204, 481, 497–501, 507, 589 required for humidification 547 transient 38 energy costs 6–7, 386, 390, 471 energy estimating variable-base, degree-day method 295, Principles of HVAC 301–302, 308 energy recovery 415 enthalpy 12, 14, 17–19, 22, 24–25, 28, 31–33, 36, 41, 44–45, 48, 56–57, 59–60, 62– 64, 67– 69, 71, 89, 121, 135–136, 191, 203, 298, 405, 433, 472, 497, 502, 504, 519, 521, 567, 577, 581 enthalpy-concentration diagram 22, 26, 28, 63 entropy 11–12, 14, 17–19, 22, 24, 30, 32–33, 43– 44, 56–57, 59–60, 577 equipment service life 380–381, 386, 415 evaporative air cooler 487 evaporative air equipment 487 evaporator 44–45, 47–50, 248, 297, 408, 415, 421, 434, 439, 446, 453, 456, 457, 467, 469, 471, 472, 475–477, 482, 500–501, 509, 519, 522–523, 525–528, 532–533, 567, 575, 583–584 exfiltration 74, 146–147, 156, 199 expansion chamber 432, 434, 439, 446–447 Expansion device 523 expansion device 47, 49, 456–458, 509, 533 expansion valve 45, 457 extended surface 481, 534, 553, 569 exterior solar attenuation coefficients 232 F fan 1–7, 67, 70, 72, 74, 76, 145–146, 156, 190– 191, 219, 223, 238, 241, 243, 249–250, 295–296, 298–299, 315–316, 322–324, 347–349, 352–353, 358, 360–361, 380, 382, 395–396, 399–400, 402–403, 405– 406, 408, 410–411, 416–419, 421–423, 445, 449, 453, 455–457, 461, 473, 481, 490–491, 504, 507, 535, 544, 547, 560, 580, 584, 586, 588–589 fan coil unit 457 fan coil units 421–422 fan laws 353, 358–359, 377 fan rooms 410 fan selection 359–360, 481 fan types 352 fans 352–353, 359 fenestration surfaces 195, 225 First Law of Thermodynamics 11, 40–46, 67, 72, 519, 567 fouling factor 520, 570–571, 580, 584 freeze prevention 409, 448–449 fuels 5, 295, 380, 385, 408, 541–543, 550 furnace commercial 547–549 residential 545, 547 G green buildings H heat 42, 520, 527, 560–561, 565, 568–569, 571, 573–574, 582 heat balance 220–223, 225, 238, 240, 251, 254, 256, 296–297, 472–475 heat exchanger 1, 49–50, 52, 68, 79, 146, 156, 297, 358, 382, 408–409, 431–434, 443– 445, 447, 450–451, 457–459, 467, 469, 471, 476, 488, 497, 499–501, 505–506, 532, 537, 544–546, 548, 550, 552, 559, 565–571, 573–575, 580, 589 heat exchanger design equation 567 heat gain appliances 219, 223, 244–245, 251, 254 computation 222, 251 computation of 223, 232, 234, 238 copiers 244–245, 251 fenestration 223, 225–226, 230, 233, 250 hospital and laboratory equipment 243, 248 interior surfaces 232, 237 laboratory equipment 157, 244 laser printers 245, 251 medical equipment 243–244, 248 monitors 244 office equipment 243–245, 252–253 outdoor air 70, 219, 221, 223–225, 232, 249–250, 271 people 219, 234, 251, 254, 257 walls and roofs 219, 223, 252–253 heat load 4, 74, 77, 79, 147, 171, 207, 272, 413, 417, 428, 473, 488–489, 523, 567, 587 heat loss basements 192, 200 ceiling and roof 200 calculation sheet 204 concrete slab floor 201 infiltration 192, 193, 202 heat pumps 5–6, 42, 49, 295, 380, 382, 421, 453, 458–459, 467–469, 471–472, 476, 510, 548, 554 heat recovery 6, 146, 308, 380, 407, 410, 423, 434, 467, 472–476, 479, 497, 499–501, 503–504, 544, 547–548, 554 heat sources, conditioned spaces 234, 497–498, 501–502, 504 heat transfer 15, 36, 38, 43, 47–49, 51–52, 67, 69, 77–78, 82, 141, 145, 156, 159, 163, 168– 169, 172, 192, 198–200, 219, 223–225, 232, 238, 243, 251, 253–254, 262, 271, 295–296, 322, 401, 431–433, 448, 450, 459, 469, 471, 477, 482, 486, 499–501, 513, 516, 520–522, 527, 535, 542, 545, 547, 550–551, 559–561, 564–568, 570– 572, 574, 576, 582 heat transfer coefficient 8, 82, 141, 156, 158, 199, 220, 252, 271, 433, 443, 505, 520, 526, 528, 560, 565, 568–569, 572, 573–574 heating coils 323, 433, 444, 450, 462, 463, 481, 486, 487, 498, 559, 566 electric 553 values of fuels 542 heating load 8, 72, 136, 145, 189, 191–192, 198– 200, 203, 205–206, 219, 256–257, 271, 396–397, 419, 474, 554, 588–589 heating load factor 200, 202 heating load methodology 198 humidification 2, 67, 88, 136, 145, 147, 475, 490–491, 547–548 humidifiers 153, 245, 380, 405, 490–493, 589 hydraulic components 432, 436–439 hydronic systems 8, 368–369, 431–451 load control 441–445 piping design 440–442, 445 I infiltration 67, 74, 136, 145–152, 189, 195, 197– 200, 216, 219–220, 249, 254, 262, 271, Index 295, 301, 308, 462, 547, 555 heat loss 202 infiltration driving force 193 infrared heaters 544, 548–549 insulation 7, 84, 405, 444, 448, 463–464, 475, 477, 553, 586, 589 interior attenuation coefficient 197, 235 interior solar attenuation coefficient 233, 235, 288 internal energy 12, 14, 22, 36, 38, 40, 43, 220, 561 isentropic exponent 44 L leakage area 149–150, 193–194, 203, 214, 513 LEED 8, 495 life of equipment 389, 584 liquid coolers 525, 527, 528 lithium bromide-water absorption cycle 533 charts 27, 28 load estimating fundamentals 145–154, 156– 159, 169–171 M maintenance 409 maintenance costs 380–381, 386–387, 389–390 mass, conservation of 13, 67 mean temperature difference 163, 181, 433, 486, 520, 527, 567–568 metabolic rate 84 moisture transfer, permeable building materials 249 Mollier diagram 16, 22–23 N noise control 362, 410 O Orsat 543, 555 outdoor air 220 overall heat transfer coefficient 252, 433, 520, 527, 528, 568–569 P panel heating and cooling 461–465 payback period 390 peak exterior irradiance 196, 203 People 254 pipe size data 363–364 sizing calculations 366 piping 1–3, 156, 219, 296, 315, 322, 365–366, 368, 380, 406, 408–411, 422–423, 431– 433, 436–437, 439–441, 443–445, 447– 451, 457, 459, 461–463, 469, 471, 475, 482–483, 486, 498–499, 516, 544, 550– 552, 584 piping circuits 440, 449 piping curcuits 440–442 properties of a substance 13–14 Psychrometric chart 37 psychrometric chart 2, 4, 36–37, 65, 68, 70, 74– 75, 205, 485, 488 psychrometrics 11, 30–31 moist air thermodynamic properties table 33 593 pump curves 368–369, 436, 437 pump laws 368 pumps 3, 5–6, 42, 49, 241, 295–296, 315, 367– 368, 380, 382, 400, 406, 409–410, 421, 432, 435–438, 441–443, 445, 448–449, 453, 456, 458–459, 461, 467–469, 498, 510, 532, 548, 554, 580, 586, 589 R radiant heaters 382, 461, 544, 548 radiant time series 219, 222, 250–252, 254, 256, 263, 266, 268, 271 radiant/convective percentages 244 radiators 3, 421, 432, 552–554 reciprocating 5, 367, 409, 453, 467, 472, 477, 509–512, 516, 526 recovery loops 497, 499 refrigerant aqua-ammonia 26 expansion device 47, 522, 533 lithium bromide-water 28, 532 properties of 527 refrigeration 3, 4, 7, 11, 22, 44–49, 72, 140, 145, 365, 379–380, 396, 401, 405, 408–411, 421, 423, 434, 444–445, 456, 458–459, 467, 471, 474–475, 482, 485, 488, 509, 513, 515–519, 522, 525, 527, 533–535, 540, 542, 571–572, 582, 584 equipment 401, 408–410, 467, 509, 527 load calculation 483 refrigeration equipment 140, 380 reheat systems 417 relative humidity 31, 83, 86, 88, 89, 136, 147, 205, 250, 360, 417, 475, 488, 547, 586 residential 2–6, 8, 81, 84, 89, 136, 146, 148, 151, 153, 189–192, 194–195, 197, 202, 208, 212, 233, 288, 308, 368–369, 396, 405, 412, 415, 431, 440–443, 449, 454, 457– 458, 461, 467, 469, 490, 515, 542, 544, 547, 548, 552, 554 residential furnace 355, 545, 548 residential load factor 192 roof conduction time series (CTS) 257 R-value 158–159, 168, 170, 218–201 S seasonal efficiency 300 Second Law of Thermodynamics 11, 14, 42–44, 559 sensible heat factor 74, 191, 203, 457 sensible heat ratio 74, 76 sol-air temperature 221–224, 251, 263, 267, 279 solar heat gain coefficient 192–193, 203, 213, 223, 226, 230, 232, 260, 280 solar properties 225–227, 230, 233, 236 sorption 488–490 special allowance factors, for nonincandescent light fixtures 234, 239–240, 262 specific heat 14, 22, 24, 164, 258, 432–433, 450, 471 steam properties 17–19, 23, 29 surface conductance 158–159 surface temperature 68, 79, 88, 136, 142, 169– 170, 199, 201, 220–222, 254, 401, 461, 464, 469, 487, 560–561, 563, 574 sustainability 7–8, 295 system air-conditioning 6, 8, 67, 189, 219, 223, 250, 322, 358, 360, 379 chilled-water 8, 140, 445, 448–449, 469 closed water 432, 477 dual-temperature 437, 445 systems air-and-water 398, 404, 420 air-conditioning 395–411, 453, 483, 515, 572 central air-conditioning 210, 223, 400–401 chilled water 444–445 closed water 432–438, 440 closed-stationary 41 cogeneration 467 computer modeling 296 design parameters 396–397 dual-stream 394 dual-temperature 445–446 duct 150, 316–317, 320, 322–324, 353, 417, 450 environmental control 1, 81, 396, 401, 586 heat-cool-off 396 heat pump 415, 458, 467, 469–470 heat recovery 380, 410, 467, 472–473, 475, 554 low-temperature 420 low-temperature heating 443 multiple 401 option constraints 397 primary 407–409, 589 reheat 396 selection and design 396 single-path 72, 74 through-the-wall conditioner 456 variable air volume 395–396, 418 T temperature average winter 137 balance-point 300–302, 308 break-even 473–475 calculating surface 170 classifications 431 dew-point 4, 31, 82, 89, 121, 136, 396, 404, 420, 422, 434, 445, 461–462, 492 dry-bulb 30, 36, 69, 71, 82–83, 89, 121, 135–136, 223, 234, 250, 262, 295, 300, 308, 360, 395, 408, 420, 469, 504, 522, 548 operative 82, 85, 143 wet-bulb 30–31, 36, 82, 89, 121, 135, 136, 189, 191, 223, 308, 457, 474, 485, 487, 522, 535 terminal units 298, 323–324, 380, 418, 422, 443, 445, 449–450, 552–553 thermal comfort 84–85 components 432–435 conductivity 158, 201, 450, 471, 559–560, 582 thermal resistance 84, 161, 196, 569–570 of surfaces 159 thermal sensation scale 83 thermodynamic properties moist air table 33 thermodynamics 11, 13, 36, 38, 40, 42, 44, 46, 49, 67, 527, 567 applied to HVAC processes 67 basic equations 44, 72 594 first law 11, 40–42, 44, 46, 67, 519, 567 heat pumps 42, 49 processes and cycles 12 properties of moist air 30, 32–33, 36, 60 properties of water 16–19 reversibility 12–13 second law 11, 14, 42–44, 559 third law 44 zeroth law 13 thermophysical properties 527, 560, 574 total equivalent temperature differential (TETD) method 221 transfer function method (TFM) 222 U U-factor 158, 159, 168, 169, 173, 175, 176–177, 188, 192, 200, 202, 205, 217, 223, 226, 232, Principles of HVAC 253, 255–257, 271 determining 159 unit heaters 3, 382, 403, 421, 433, 443, 446, 544, 548, 554 unitary air conditioners 453–456, 458, 525 V valve expansion 482–483, 522–523 sizing 442 variable air volume 5, 6, 154, 298, 396, 400, 403, 417 ventilation 2, 67, 73, 136, 145,–148, 151–154, 157, 189, 191–192, 194, 197–199, 206, 216, 219, 420, 487, 494, 495 ventilation and infiltration air 145, 249 W wall conductance time series (CTS) 255 water coil 382, 408, 419–420, 449, 487, 491– 492, 499–500, 504 water coils 444, 482, 486 water system power and energy of 400 wet-bulb temperature 30–31, 36, 82, 89, 121, 135–136, 475, 487, 504 wind chill temperatures 140, 144 windows 1, 74, 88, 145–148, 151, 159, 169, 175, 192, 195, 197, 199, 204–206, 210–220, 222, 251, 254, 260, 262, 268, 302, 410, 421, 471, 475, 552, 586, 589 winter average temperatures 137 It is suitable both as a textbook and as a reference book for undergraduate engineering courses in the field of air conditioning, heating, and ventilation; for similar courses at technical and vocational schools; for continuing education and refresher short courses for engineers; and for adult education courses for professionals other than engineers, especially when combined with ASHRAE Handbook— Fundamentals The material is divided into three major sections: general concepts, Chapters 1–10; air-conditioning systems, Chapters 11–16; and HVAC&R equipment, Chapters 17–20 There are several significant changes in this revised edition Chapter has new values for climatic design information Chapter has been extensively revised with new design data In addition, the chapters on system design and equipment have been significantly revised to reflect recent changes and concepts in modern heating and air-conditioning system practices This book includes access to a website containing the Radiant Time Series (RTS) Method Load Calculation Spreadsheets, which are intended as an educational tool both for the student and for the experienced engineer wishing to explore the RTS method These spreadsheets allow the user to perform RTS cooling load calculations for lights, people, equipment, walls/roofs, and fenestration components using design day weather profiles for any month Cooling and heating loads can be calculated for individual rooms or block load zones Twelve-month cooling calculations can be done to determine the month and time of peak cooling load for each room or block load zone In addition, room/zone worksheets can be copied and modified within the spreadsheet to analyze as many rooms or zones as desired; the number of rooms/zones is limited only by the available computer memory Principles of HVAC Principles of Heating, Ventilating, and Air Conditioning is a textbook based on the 2017 ASHRAE Handbook—Fundamentals It contains the most current ASHRAE procedures and definitive, yet easy to understand, treatment of building HVAC systems, from basic principles through design and operation 8th Edition Principles of Heating Ventilating and Air Conditioning 8th Edition Based on the 2017 ASHRAE Handbook—Fundamentals Ronald H Howell ISBN: 978-1-939200-73-0 (hardback) 978-1-939200-74-7 (PDF) ASHRAE 1791 Tullie Circle Atlanta, GA 30329-2305 404-636-8400 (worldwide) www.ashrae.org PHVAC TEXT_cover.indd Product Code:200730 90567 7/17 781939 7/12/2017 12:01:20 PM