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4、g-in-Publication DataSpitler, Jeffrey D.Load calculation applications manual / Jeffrey D. Spitler. - SI ed.p. cm.Includes bibliographical references and index.Summary: “Focuses on the radiant time series and heat balance methods for calculating cooling loads in nonresidential buildings. The intended
5、 audience is relatively new engineers who are learning to do load calculations, as well as experienced engineers who wish to learn the radiant time series method“-Provided by publisher.ISBN 978-1-933742-72-4 (hardcover)1. Air conditioning-Efficiency. 2. Cooling load-Measurement. 3. Heating load-Meas
6、urement. 4. Heating. I. Title. TH7687.5.S683 2010697.93-dc222010007767ASHRAE STAFFSPECIAL PUBLICATIONSMark S. OwenEditor/Group Manager of Handbook and Special PublicationsCindy Sheffield MichaelsManaging EditorJames Madison WalkerAssociate EditorAmelia SandersAssistant EditorElisabeth ParrishAssista
7、nt EditorMichshell PhillipsEditorial CoordinatorPUBLISHING SERVICESDavid SoltisGroup ManagerTracy BeckerGraphic Applications SpecialistJayne JacksonPublication Traffic AdministratorPUBLISHERW. Stephen Comstock 2010, American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc. (www
8、.ashrae.org). For personal use only. Additional reproduction, distribution, or transmission in either print or digital form is not permitted without ASHRAEs prior written permission. ContentsForeword . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
9、. . . . . . . . . . . VIIChapter OneIntroduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1Chapter TwoFundamentals of Heat Transfer and Thermodynamics . . . . . . . . . . . . . . . . . . . . . . . . . 5Chapter ThreeThermal Property D
10、ata . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17Chapter FourEnvironmental Design Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67Chapter FiveInfiltration . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
11、 . . . . . . . . . . . . . . . . . . . . . . . . . . 81Chapter SixInternal Heat Gain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105Chapter SevenFundamentals of the Radiant Time Series Method . . . . . . . . . . . . . . . . . . . . . . . . . 127Cha
12、pter EightApplication of the RTSMDetailed Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 161Chapter NineAir Systems, Loads, IAQ, and Psychrometrics . . . . . . . . . . . . . . . . . . . . . . . . . . . . 201Chapter TenHeating Load Calculations . . . . . . . . . . . . . . . . . . .
13、 . . . . . . . . . . . . . . . . . . . . . . . 225Chapter ElevenHeat Balance Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 235Appendix APsychrometric ProcessesBasic Principles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 245Appendix BSp
14、readsheet Implementation of the RTSM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 267Appendix CCalculation of CTSFs and RTFs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 299Appendix DSolar Radiation and Heat Gain . . . . . . . . . . . . . . . . . . .
15、 . . . . . . . . . . . . . . . . . . . . 305Appendix ETreatment of Thermal Bridges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 317Appendix FTreatment of Uncontrolled Spaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 325Appendix GCorrecti
16、on Factor for High-Conductance Surface Zones . . . . . . . . . . . . . . . . . . . . . 331Index. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 335 2010, American Society of Heating, Refrigerating and Air-Conditioning Engin
17、eers, Inc. (www.ashrae.org). For personal use only. Additional reproduction, distribution, or transmission in either print or digital form is not permitted without ASHRAEs prior written permission. 2010, American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc. (www.ashrae.org)
18、. For personal use only. Additional reproduction, distribution, or transmission in either print or digital form is not permitted without ASHRAEs prior written permission. VIIForewordThis manual is the fourth in a series of load calculation manuals published by the American Society of Heating, Refrig
19、erating and Air-Conditioning Engineers, Inc. The first in the series, Cooling and Heating Load Calculation Manual, by William Rudoy and Joseph Cuba, was published in 1980. A second edition, by Faye McQuis-ton and myself, was published in 1992 and focused on new developments in the trans-fer function
20、 method and the cooling load temperature difference method. Subsequent to the second edition, ASHRAE Technical Committee 4.1, Load Calculations Data and Procedures, commissioned additional research. This research led to the adapta-tion of the heat balance method for use in load calculation procedure
21、s and develop-ment of the radiant time series method (RTSM) as the recommended simplified procedure. Both methods were presented in the third volume of this seriesCooling and Heating Load Calculation Principles, by Curtis Pedersen, Daniel Fisher, Richard Liesen, and myself.The Load Calculation Appli
22、cations Manual, also sponsored by TC 4.1, builds on the past three, and some parts are taken directly from previous versions. New develop-ments in data and methods have led to numerous revisions. This manual, intended to be more applications-oriented, includes extensive step-by-step examples for the
23、 RTSM.This work, more so than many technical books, represents the work of many indi-viduals, including:Authors of the previous three versions, who are named above.Tom Lawrence and Brittany Romig of the University of Georgia, who made the SIedition of the book possible by converting all of the table
24、s, figures, equations, andexamples from I-P to SI units. In this process, they uncovered various errors andunclear descriptions that would not otherwise have been found.Numerous ASHRAE volunteers and ASHRAE researchers who have developedmaterial for the ASHRAE Handbook that has now been incorporated
25、.Members of the Project Monitoring Subcommittee, including Chris Wilkins, SteveBruning, Larry Sun, and Bob Doeffinger, who have provided extensive comments,guidance, and direction. My graduate student, Bereket Nigusse, who developed most of the spreadsheetsunderlying the examples and whose PhD resea
26、rch has led to a number of develop-ments in the RTSM that are incorporated into this manual. Amelia Sanders of ASHRAE Special Publications, who edited and laid out thismanual.The contributions of all of these individuals are gratefully acknowledged.Jeffrey D. Spitler 2010, American Society of Heatin
27、g, Refrigerating and Air-Conditioning Engineers, Inc. (www.ashrae.org). For personal use only. Additional reproduction, distribution, or transmission in either print or digital form is not permitted without ASHRAEs prior written permission. 2010, American Society of Heating, Refrigerating and Air-Co
28、nditioning Engineers, Inc. (www.ashrae.org). For personal use only. Additional reproduction, distribution, or transmission in either print or digital form is not permitted without ASHRAEs prior written permission. 11Introductionhis manual focuses on two methods for calculating cooling loads in non-r
29、esidential buildingsthe heat balance method (HBM) and the radiant time series method (RTSM). The two methods presented are based on fundamental heat balance principles, directly so in the case of the HBM, and less directly so in the case of the RTSM. Both methods were first fully presented for use i
30、n design load calculations in the predecessor to this volume, Cooling and Heating Load Calculation Principles (Pedersen et al. 1998). Since that time, there have been a number of developments in the RTSM. This publication attempts to bring the previous volume up to date, incorporate new developments
31、, and provide a more in-depth treatment of the method. 1.1 Definition of a Cooling LoadWhen an HVAC system is operating, the rate at which it removes heat from a space is the instantaneous heat extraction rate for that space. The concept of a design cooling load derives from the need to determine an
32、 HVAC system size that, under extreme conditions, will provide some specified condition within a space. The space served by an HVAC system commonly is referred to as a thermal zone or just a zone. Usually, the indoor boundary condition associated with a cooling load calculation is a constant interio
33、r dry-bulb temperature, but it could be a more complex function, such as a thermal comfort condition. What constitutes extreme conditions can be inter-preted in many ways. Generally, for an office it would be assumed to be a clear sunlit day with high outdoor wet-bulb and dry-bulb temperatures, high
34、 office occupancy, and a correspondingly high use of equipment and lights. Design conditions assumed for a cooling load determination are subjective. But, after the design conditions are agreed upon, the design cooling load represents the maximumor peak heat extrac-tionrate under those conditions.1.
35、2 The Basic Design QuestionsIn considering the problem of design from the HVAC system engineers view-point, there are three main questions that a designer needs to address. They are: 1. What is the required equipment size? 2. How do the heating/cooling requirements vary spatially within the building
36、? 3. What are the relative sizes of the various contributors to the heating/cooling load?The cooling load calculation is performed primarily to answer the second ques-tion, that is, to provide a basis for specifying the required airflow to individual spaces within the building. The calculation also
37、is critical to professionally answering the first question. Answers to the third question help the designer make choices to improve the performance or efficiency of the design and occasionally may influence architectural designers regarding energy-sensitive consequences.T 2010, American Society of H
38、eating, Refrigerating and Air-Conditioning Engineers, Inc. (www.ashrae.org). For personal use only. Additional reproduction, distribution, or transmission in either print or digital form is not permitted without ASHRAEs prior written permission. 2Load Calculation Applications Manual, SI Edition1.3 O
39、verview of the ASHRAE Load Calculation Methods1.3.1 Models and RealityAll calculation procedures involve some kind of model, and all models are approximate. The amount of detail involved in a model depends on the purpose of that model. This is the reality of modeling, which should describe only the
40、variables and parameters that are significant to the problem at hand. The challenge is to ensure that no significant aspects of the process or device being modeled are excluded and, at the same time, that unnecessary detail is avoided.A complete, detailed model of all of the heat transfer processes
41、occurring in a building would be very complex and would be impractical as a computational model, even today. However, generally building physics researchers and practitioners agree that certain modeling simplifications are reasonable and appropriate under a broad range of situations. The most fundam
42、ental of these is that the air in the space can be modeled as well-stirred. This means there is an approximately uniform temperature throughout the space due to mixing. This modeling assumption is quite valid over a wide range of conditions. With that as a basis, it is possible to formulate fundamen
43、tal models for the various heat transfer and thermodynamic processes that occur. The resulting formulation is called the HBM. There is an introduction to the general prin-ciples of the HBM in Chapter 2 and further description in Chapter 11.1.3.2 The Heat Balance MethodThe processes that make up the
44、heat balance model can be visualized using the schematic shown in Figure 1.1. It consists of four distinct processes:1. the outside face heat balance2. the wall conduction process3. the inside face heat balance4. the air heat balanceFigure 1.1 shows the heat balance process in detail for a single op
45、aque surface. The shaded part of the figure is replicated for each of the surfaces enclosing the zone. The process for transparent surfaces would be similar to that shown but would not have the absorbed solar component at the outside surface. Instead, it would be split into two parts: an inward-flow
46、ing fraction and an outward-flowing fraction. These fractional parts would participate in the inside and outside face heat balances. The transparent surfaces would, of course, provide the transmitted solar component that contributes to the inside heat balance. The double-ended arrows indicate schema
47、tically where there is a heat exchange, and the single-ended arrows indicate where the interaction is one way. The formula-tion of the heat balance consists of mathematically describing the four major pro-cesses, shown as rounded blocks in the figure.1.3.3 The Radiant Time Series MethodThe RTSM is a
48、 relatively new method for performing design cooling load calcu-lations. It is derived directly from the HBM and effectively replaced all other simpli-fied (non-heat-balance) methods such as the transfer function method (TFM), the cooling load temperature difference/solar cooling load/cooling load f
49、actor method (CLTD/SCL/CLFM), and the total equivalent temperature difference/time averaging method (TETD/TAM). The RTSM was developed in response to a desire to offer a method that was rigorous yet did not require iterative calculations of the previous methods. In addition, the periodic response factors and radiant time factors have clear 2010, American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc. (www.ashrae.org). For personal use only. Additional reproduction, distribution, or transmissio
