ANSI ASHRAE 160-2016 Criteria for Moisture-Control Design Analysis in Buildings.pdf

1、ANSI/ASHRAE Standard 160-2016(Supersedes ANSI/ASHRAE Standard 160-2009)Includes ANSI/ASHRAE addenda listed in Annex DCriteria forMoisture-ControlDesign Analysis inBuildingsSee Annex D for approval dates by the ASHRAE Standards Committee, the ASHRAE Board of Directors, and the AmericanNational Standa

2、rds Institute.This Standard is under continuous maintenance by a Standing Standard Project Committee (SSPC) for which the StandardsCommittee has established a documented program for regular publication of addenda or revisions, including procedures fortimely, documented, consensus action on requests

3、for change to any part of the Standard. The change submittal form,instructions, and deadlines may be obtained in electronic form from the ASHRAE website (www.ashrae.org) or in paperform from the Senior Manager of Standards. The latest edition of an ASHRAE Standard may be purchased from theASHRAE web

4、site (www.ashrae.org) or from ASHRAE Customer Service, 1791 Tullie Circle, NE, Atlanta, GA 30329-2305.E-mail: ordersashrae.org. Fax: 678-539-2129. Telephone: 404-636-8400 (worldwide), or toll free 1-800-527-4723 (fororders in US and Canada). For reprint permission, go to www.ashrae.org/permissions.

5、2016 ASHRAE ISSN 1041-2336SPECIAL NOTEThis American National Standard (ANS) is a national voluntary consensus Standard developed under the auspices of ASHRAE. Consensus is definedby the American National Standards Institute (ANSI), of which ASHRAE is a member and which has approved this Standard as

6、an ANS, as“substantial agreement reached by directly and materially affected interest categories. This signifies the concurrence of more than a simple majority,but not necessarily unanimity. Consensus requires that all views and objections be considered, and that an effort be made toward their resol

7、ution.”Compliance with this Standard is voluntary until and unless a legal jurisdiction makes compliance mandatory through legislation. ASHRAE obtains consensus through participation of its national and international members, associated societies, and public review.ASHRAE Standards are prepared by a

8、 Project Committee appointed specifically for the purpose of writing the Standard. The ProjectCommittee Chair and Vice-Chair must be members of ASHRAE; while other committee members may or may not be ASHRAE members, allmust be technically qualified in the subject area of the Standard. Every effort i

9、s made to balance the concerned interests on all Project Committees. The Senior Manager of Standards of ASHRAE should be contacted fora. interpretation of the contents of this Standard,b. participation in the next review of the Standard,c. offering constructive criticism for improving the Standard,

10、ord. permission to reprint portions of the Standard.DISCLAIMERASHRAE uses its best efforts to promulgate Standards and Guidelines for the benefit of the public in light of available information and acceptedindustry practices. However, ASHRAE does not guarantee, certify, or assure the safety or perfo

11、rmance of any products, components, or systemstested, installed, or operated in accordance with ASHRAEs Standards or Guidelines or that any tests conducted under its Standards or Guidelineswill be nonhazardous or free from risk.ASHRAE INDUSTRIAL ADVERTISING POLICY ON STANDARDSASHRAE Standards and Gu

12、idelines are established to assist industry and the public by offering a uniform method of testing for rating purposes, bysuggesting safe practices in designing and installing equipment, by providing proper definitions of this equipment, and by providing other informationthat may serve to guide the

13、industry. The creation of ASHRAE Standards and Guidelines is determined by the need for them, and conformanceto them is completely voluntary.In referring to this Standard or Guideline and in marking of equipment and in advertising, no claim shall be made, either stated or implied,that the product ha

14、s been approved by ASHRAE.ASHRAE STANDARDS COMMITTEE 20162017Rita M. Harrold, Chair Michael W. Gallagher Cyrus H. NasseriSteven J. Emmerich, Vice-Chair Walter T. Grondzik David RobinJames D. Aswegan Vinod P. Gupta Peter SimmondsNiels Bidstrup Susanna S. Hanson Dennis A. StankeDonald M. Brundage Roge

15、r L. Hedrick Wayne H. Stoppelmoor, Jr.Drury B. Crawley Rick M. Heiden Jack H. ZarourJohn F. Dunlap, Srinivas Katipamula William F. Walter, BOD ExOJames W. Earley, Jr. Cesar L. Lim Patricia Graef, COKeith I. Emerson Arsen K. MelikovJulie M. Ferguson R. Lee Millies, Jr.Stephanie C. Reiniche, Senior Ma

16、nager of StandardsASHRAE Standing Standard Project Committee 160Cognizant TC: 4.4, Building Materials and Building Envelope PerformanceSPLS Liaison: Keith I. EmersonStanley D. Gatland, II*, Chair Elliott Horner* Fitsum Tariku*Achilles N. Karagiozis*, Vice-Chair Jonathan Humble* Eric D. Werling*Samue

17、l Glass, Secretary Wahid Maref* Elyse IngleseFlorian Antretter* B. Simon Pallin* Alejandra NietoLois Arena* Christopher J. Schumacher* Denotes members of voting status when the document was approved for publicationCONTENTSANSI/ASHRAE Standard 160-2016,Criteria for Moisture-Control Design Analysis in

18、 BuildingsSECTION PAGEForeword .21 Purpose.32 Scope33 Definitions, Abbreviations, and Symbols.34 Criteria for Design Parameters45 Criteria for Selecting Analytical Procedures76 Moisture Performance Evaluation Criteria 77 Reporting.98 References10Informative Annex A: Flowcharts.11Informative Annex B:

19、 Commentary on Standard 16013Informative Annex C: Bibliography16Informative Annex D: Addenda Description 17NOTEApproved addenda, errata, or interpretations for this standard can be downloaded free of charge from the ASHRAEwebsite at www.ashrae.org/technology. 2016 ASHRAE1791 Tullie Circle NE Atlanta

20、, GA 30329 www.ashrae.org All rights reserved.ASHRAE is a registered trademark of the American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc.ANSI is a registered trademark of the American National Standards Institute.2 ANSI/ASHRAE Standard 160-2016(This foreword is not part o

21、f this standard. It is merelyinformative and does not contain requirements necessaryfor conformance to the standard. It has not been pro-cessed according to the ANSI requirements for a standardand may contain material that has not been subject topublic review or a consensus process. Unresolved objec

22、-tors on informative material are not offered the right toappeal at ASHRAE or ANSI.)FOREWORDAlthough the majority of new buildings are safe, comfortable,and designed to provide effective protection against moisture-related problems, there are a certain number of buildingsbuilt each year that do expe

23、rience moisture or mold problems.Whether this number is now increasing and whether theincrease is due to the greater emphasis on energy-efficiencymeasures today is a widely debated topic. This purpose of thisstandard is not to answer either of these questions but ratherto provide guidance on how to

24、best design buildings with ade-quate moisture control features. Given its position as a leaderin the proper design of heating, ventilating, and air-condi-tioning equipment, ASHRAE is uniquely qualified to providesuch guidance.During the last two decades, a number of computer simu-lation tools have b

25、een developed to predict thermal and mois-ture conditions in buildings and the building envelope. Inaddition to their use as forensic tools in the investigation ofbuilding failures, these computer models are increasinglyused to make recommendations for building design in variousclimates. However, re

26、sults obtained with these models areextremely sensitive to the assumed moisture boundary condi-tions. For instance, during winter in cold climates, the mois-ture conditions in walls depend greatly on the indoorhumidity conditions. Thus, a consistent approach to moisturedesign demands a consistent fr

27、amework for design assump-tions, or assumed “loads.” The question whether design fea-tures such as vapor retarders or ventilation systems arenecessary cannot be answered objectively unless there is aconsensus definition of the interior and exterior moistureboundary conditions that the building is ex

28、pected to be ableto sustain without negative consequences to itself or its inhab-itants. This standard formulates design assumptions for mois-ture design analysis and criteria for acceptable performance. Ideally, a design analysis involves the determination ofthe probability of failure and treats al

29、l design parameters andloads as stochastic variables. However, sufficient data areoften not available to make a full statistical treatment practi-cal. Instead, where only limited data exist, a moisture designprotocol must be based on a combination of statistical dataand professional judgment. Anothe

30、r judgment involves thechoice of an acceptable probability of the occurrence of dam-age. Although it is common to impose very stringent criteriafor structural design because of safety concerns, moisturedamage usually occurs over a long period of time and usuallyhas less catastrophic, although someti

31、mes costly, conse-quences. An international consensus has emerged that theanalysis should be predicated on loads that will not beexceeded 90% of the time. This standard adopts thisapproach.In a moisture analysis for building envelope design, thechoice of indoor environmental conditions is extremelyi

32、mportant, especially for buildings in cold climates. This stan-dard opts for a design indoor climate definition that is basedon engineering principles, is independent of construction,and reflects the influence of ventilation and air-conditioningequipment and controls that may or may not be part of t

33、hebuilding design. In buildings where indoor humidity and tem-perature are explicitly controlled, the building envelope per-formance should be evaluated with the intended indoordesign conditions. In residential buildings, indoor humidity israrely explicitly controlled, so default design assumptions

34、areneeded for these buildings. In general, the standard encour-ages designers to use their own design parameter values ifthey are known and part of the design. If they are unknown ornot included in the design, the standard provides default val-ues for those loads and parameters.The standard does not

35、 address design details that dealwith rainwater intrusion, plumbing leaks, ground water, andwater damage caused by natural disasters such as floods andhurricanes. While proper design for these issues is extremelyimportant, and damage from such events involves a large per-centage of moisture damage i

36、n buildings, they can be moreeffectively addressed by codes, training of the trades, and spe-cific design guidelines (see Annex B, “Commentary on Stan-dard 160”). This standard assumes that appropriate measureswere taken to limit bulk water entry into the building andbuilding envelope. It does not i

37、ntend to replace the judgmentof the design professional. Rather, it provides a framework forthe design professional to identify and consider factors thatare important to the durability and serviceability of the build-ing. In addition, many items in this standard are based onincomplete information an

38、d are, therefore, partially based onthe best professional judgment of the standard committee atthe time of writing. The development of this standard haspointed to many unanswered questions, questions that hope-fully will be addressed and answered by research in the nearfuture.Since the document was

39、published in 2009, ASHRAEStandard 160 has incorporated several addenda focused on a. simplifying the conditions necessary to minimize moldgrowth by eliminating two criteria,b. limiting indoor relative humidity to 70% or less in thedesign analysis and revising the residential design mois-ture generat

40、ion rates,c. simplifying the calculation procedure for wind-driven rainwithout significantly impacting the accuracy of results,d. updating references, ande. replacing the simplified mold growth criterion with amold index that predicts risk, which is more consistentwith assembly performance observed

41、in the field.The revised standard reflects the current state of knowl-edge about mold growth while providing less stringent crite-rion.ANSI/ASHRAE Standard 160-2016 31. PURPOSEThe purpose of this standard is to specify performance-baseddesign criteria for predicting, mitigating, or reducing mois-tur

42、e damage to the building envelope, materials, components,systems, and furnishings, depending on climate, constructiontype, and HVAC system operation. These criteria include thefollowing:a. Criteria for selecting analytic proceduresb. Criteria for inputsc. Criteria for evaluation and use of outputs2.

43、 SCOPE2.1 This standard applies to the design of new buildings andto the retrofit and renovation of existing buildings.2.2 This standard applies to all types of buildings, buildingcomponents, and materials.2.3 This standard applies to all interior and exterior zonesand building envelope cavitiesB-1.

44、2.4 This standard does not directly address thermal comfortor acceptable indoor air qualityB-1.2.5 This standard does not address the design of buildingcomponents or envelopes to resist liquid water leakage fromsources such as rainwater, ground water, flooding, or icedams.B-1Informative Note: All su

45、perscript notes such as B-1, B-2,and so forth refer to informative commentary on the standardthat is contained in Informative Annex B.3. DEFINITIONS, ABBREVIATIONS, AND SYMBOLS3.1 Definitions24-hour running average: a continuously updated average ofvalues over the most recent 24 hours.30-day running

46、 average: a continuously updated average ofvalues over the most recent 30 days.airtight construction: construction in which the buildingenvelope is designed with a continuous air barrierB-2.as-built: the condition of a building assembly in a completedstructure that accounts for an expected level of

47、deviation fromthe ideal construction of that assembly in order to allow forconstruction tolerances, discontinuities, and minor defects.continuous air barrier: the combination of interconnectedmaterials, assemblies, and flexible sealed joints and compo-nents of the building envelope that provide airt

48、ightness.EMC80: the moisture content of a material expressed as aratio of the mass of water and the oven-dry mass when thematerial is in equilibrium with air at 80% rh at 20C (68F).EMC90: the moisture content of a material expressed as aratio of the mass of water and the oven-dry mass when themateri

49、al is in equilibrium with air at 90% rh at 20C (68F).low-slope roof: a roof with a slope of less than 1 in 6, or 9.5.moisture-design reference years: the 10th-percentile warm-est and 10th-percentile coldest years from a 30-year weatheranalysisB-3.residential: pertaining to single-family or multifamily dwell-ings, including high-rise residential buildings and manufac-tured homes.rain runoff: the rainwater contribution that is drained frombuilding elements above the element under consideration.steep-slope roof: a roof with a slope equal to or greater than 1in 6, or 9.5.