1、Designation: E1998 11 (Reapproved 2018)Standard Guide forAssessing Depressurization-Induced Backdrafting andSpillage from Vented Combustion Appliances1This standard is issued under the fixed designation E1998; the number immediately following the designation indicates the year oforiginal adoption or
2、, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This guide describes and compares different methods forassessing the potential
3、for, or existence of, depressurization-induced backdrafting and spillage from vented residentialcombustion appliances.1.2 Assessment of depressurization-induced backdraftingand spillage is conducted under either induced depressurizationor natural conditions.1.3 Residential vented combustion applianc
4、es addressed inthis guide include hot water heaters and furnace. The guide alsois applicable to boilers.1.4 The methods given in this guide are applicable toCategory I (draft-hood- and induced-fan-equipped) furnaces.The guide does not apply to Category III (power-vent-equipped) or Category IV (direc
5、t-vent) furnaces.1.5 The methods in this guide are not intended to identifybackdrafting or spillage due to vent blockage or heat-exchanger leakage.1.6 This guide is not intended to provide a basis fordetermining compliance with code requirements on applianceand venting installation, but does include
6、 a visual assessmentof the installation. This assessment may indicate the need for athorough inspection by a qualified technician.1.7 Users of the methods in this guide should be familiarwith combustion appliance operation and with making house-tightness measurements using a blower door. Some method
7、sdescribed in this guide require familiarity with differential-pressure measurements and use of computer-based data-logging equipment.1.8 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.9 This guide does not purport to address
8、 all safetyconcerns, if any, associated with its use. It is the responsibilityof the user to establish appropriate safety, health, and envi-ronmental practices and to determine the applicability ofregulatory limitations prior to use. Carbon monoxide (CO)exposure or flame roll-out may occur when perf
9、orming certainprocedures given in this guide. See Section 7, for precautionsthat must be taken in conducting such procedures.1.10 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theD
10、evelopment of International Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2D1356 Terminology Relating to Sampling and Analysis ofAtmospheresE631 Terminology of Building ConstructionsE
11、779 Test Method for DeterminingAir Leakage Rate by FanPressurization2.2 CAN/CGSB Standard:3CAN/CGSB 51.71 The Spillage TestMethod to Determinethe Potential for Pressure-Induced Spillage from Vented,Fuel-Fired; Space HeatingAppliances; Water Heaters, andFireplaces2.3 ANSI Standard:4ANSI Z21.47 Gas-fi
12、red Central Furnace2.4 NFPA Standard:5NFPA 54 National Fuel Gas Code1This guide is under the jurisdiction of ASTM Committee E06 on Performanceof Buildings and is the direct responsibility of Subcommittee E06.41 on AirLeakage and Ventilation Performance.Current edition approved July 1, 2018. Publishe
13、d July 2018. Originally approvedin 1999. Last previous edition approved in 2011 as E1998 11. DOI: 10.1520/E1998-11R18.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer t
14、o the standards Document Summary page onthe ASTM website.3Available from Canadian General Standards Board (CGSB), 11 Laurier St.,Phase III, Place du Portage, Gatineau, Quebec K1A 0S5, Canada, http:/www.tpsgc-pwgsc.gc.ca/ongc-cgsb.4Available from American National Standards Institute (ANSI), 25 W. 43
15、rd St.,4th Floor, New York, NY 10036, http:/www.ansi.org.5Available from National Fire Protection Association (NFPA), 1 BatterymarchPark, Quincy, MA 02169-7471, http:/www.nfpa.org.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis in
16、ternational standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT)
17、Committee.13. Terminology3.1 Definitions:3.1.1 For definitions of general terms related to buildingconstruction used in this specification, refer to TerminologyE631, and for general terms related to sampling and analysis ofatmospheres, refer to Terminology D1356.3.2 Definitions of Terms Specific to
18、This Standard:3.2.1 air leakage, nthe movement or flow of air throughthe building envelope which is driven by a pressure differentialacross the envelope.3.2.2 air leakage rate, nthe volume of air movement perunit time across the building envelope.3.2.3 airtightness, nthe degree to which the building
19、envelope resists flow of air.3.2.4 blower door, na fan pressurization device incorpo-rating a controllable fan and instruments for airflow measure-ment and building pressure difference measurement thatmounts securely in a door or other opening.3.2.5 Category 1 appliance, nan appliance that operatesw
20、ith non-positive static pressure and with a vent gas tempera-ture that avoids excessive condensate production in the vent(see NFPA 54).3.2.6 Category III appliance, nan appliance that operateswith a positive vent pressure and with a vent gas temperaturethat avoids excessive condensate production in
21、the vent (seeNFPA 54).3.2.7 Category IV appliance, nan appliance that operateswith a positive vent pressure and with a vent gas temperaturethat may cause excessive condensate production in the vent(see NFPA 54).3.2.8 combustion system spillage, nentry of combustionproducts into a building from dilut
22、ion air inlets, vent connectorjoints, induced draft fan case opening, combustion air inlets, orother locations in the combustion or venting system of a ventedcombustion appliance (boiler, fireplace, furnace, or waterheater), caused by backdrafting, vent blockage, or leaks in theventing system.3.2.9
23、continuous pressure differential, nthe incrementalhouse depressurization due to fans that can be operatedcontinuously, such as furnace blower or supply/exhaust venti-lator.3.2.10 downdrafting, nthe reversal of the ordinary (up-ward) direction of air flow in a chimney or flue when no ventedcombustion
24、 appliances are operating (as opposed tobackdrafting, which occurs when vented combustion appli-ances are operating).3.2.11 house depressurization, nthe situation, pertainingto a specific location in a house, whereby the static pressure atthat location is lower than the static pressure in the immedi
25、atevicinity outside the house.3.2.11.1 DiscussionThe pressure difference between in-doors and outdoors is affected by building tightness (includingthe distribution of leakage sites across the building envelope),indoor-outdoor temperature difference, local winds, and theoperation of indoor appliances
26、 such as exhaust fans, forced-airsystem fans, and vented combustion appliances (boilers,fireplaces, furnaces, or water heaters). Thus, the existence andextent of house depressurization at a specific location variesover time, depending on outdoor conditions and the operationof indoor appliances.3.2.1
27、2 induced conditions, nconditions for house depres-surization created with the use of exhaust fans or blower door.3.2.13 induced draft (ID) fan, na fan used in a ventingsystem that removes flue gases under non-positive static ventpressure.3.2.13.1 DiscussionAn appliance with an ID fan is aCategory I
28、 appliance, as its venting system is under non-positive static vent pressure.3.2.14 intermittent pressure differential, nthe incrementalhouse depressurization due to fans that are operatedintermittently, such as clothes dryer, kitchen exhaust or bath-room fan.3.2.15 natural conditions, noutdoor temp
29、erature and windconditions that create house depressurization.3.2.16 pressure differential, npressure difference acrossthe building envelope, expressed in pascals (inches of water orpound-force per square foot or inches of mercury).3.2.17 vented combustion appliance, nincludes fossil-fuel-fired furn
30、ace, boiler or water heater vented to outside.3.2.17.1 DiscussionThe term vented combustion appli-ances in this standard excludes fireplaces and gas logs ventedto outside. Also, it does not include appliances such as gasranges or unvented space heaters.4. Summary of Guide4.1 This guide summarizes di
31、fferent methods for assessingbackdrafting and spillage from vented combustion appliances.For each method the equipment needed, test procedures, datareporting, results and interpretation, and technician and testtime required are presented. Advantages and uncertainties ofeach method are discussed.4.2
32、Assessment of depressurization-induced backdraftingand spillage is conducted under either induced depressurizationor natural conditions. Depressurization is induced in a resi-dence by deliberately operating exhaust fans or a blower-doorfan. Assessments conducted under induced conditions canindicate
33、only the potential for backdrafting and spillage.Assessments under natural conditions can indicate actualbackdrafting and spillage events. Assessments under eitherinduced or natural conditions may not be valid for weather,house tightness, or operational conditions beyond those en-countered during th
34、e period of measurements.4.3 The guide includes four types of short term testsconducted under induced conditions: (1) house depressuriza-tion test with preset criteria; (2) downdrafting test; (3) appli-ance backdrafting test; and (4) cold vent establishment pressure(CVEP) test. A continuous backdraf
35、t test to identify backdraft-ing events under natural conditions, which involves continuousmonitoring of vent differential pressures, is also described. Foridentification of spillage events or consequences thereof undernatural conditions, a continuous spillage test that involvesE1998 11 (2018)2conti
36、nuous monitoring of spillage-zone temperatures and in-door air quality is described. Because they are conducted undera variety of naturally occurring conditions, the continuousmethods can provide more definitive results for conditionsunder which tests are conducted. However, the continuousmethods al
37、so can be more time-consuming and resource-intensive to apply.4.4 A purpose of the guide is to encourage the use ofconsistent procedures for any selected method.5. Significance and Use5.1 Although a number of different methods have been usedto assess backdrafting and spillage (see NFPA54, CAN/CGSB-5
38、1.71, and 1-4)6a single well-accepted method is not yetavailable. At this point, different methods can yield differentresults. In addition, advantages and drawbacks of differentmethods have not been evaluated or described.5.2 To provide a consistent basis for selection of methods,this guide summariz
39、es different methods available to assessbackdrafting and spillage. Advantages and limitations of eachmethod are addressed.5.3 One or more of the methods described in this guideshould be performed when backdrafting or spillage fromvented combustion appliances is suspected to be the cause of apotentia
40、l problem such as elevated carbon monoxide (CO)levels or excessive moisture.5.4 The following are examples of specific conditions underwhich such methods could be performed:5.4.1 When debris or soot is evident at the draft hood,indicating that backdrafting may have occurred in the past,5.4.2 When a
41、new or replacement combustion appliance isadded to a residence,5.4.3 When a new or replacement exhaust device or system,such as a downdraft range exhaust fan, a fireplace, or afan-powered radon mitigation system, is added,5.4.4 When a residence is being remodeled or otherwisealtered to increase ener
42、gy efficiency, as with various types ofweatherization programs, and5.4.5 When a CO alarm device has alarmed and a combus-tion appliance is one of the suspected causes of the alarm.5.5 Depending on the nature of the test(s) conducted and thetest results, certain preventive or remedial actions may nee
43、d tobe taken. The following are examples:5.5.1 If any of the short-term tests indicates a potential forbackdrafting, and particularly if more than one test indicatessuch potential, then the appliance and venting system should befurther tested by a qualified technician, or remedial actionscould be ta
44、ken in accordance with 5.5.3.5.5.2 If continuous monitoring indicates that backdrafting isoccurring, and particularly if it indicates that spillage isoccurring that impacts indoor air quality (for example, elevatedCO concentrations or excessive moisture in the house), thenremedial action is indicate
45、d.5.5.3 Possible remedial actions include the following:5.5.3.1 At a minimum, a CO alarm device could be installedin the house.5.5.3.2 Limiting the use of devices or systems that increasehouse depressurization, such as fireplaces and high-volumeexhaust fans. Proper sealing of any air leakage sites,
46、especiallyat the top floor ceiling level, can also reduce house depressur-ization at the lower levels of the house.5.5.3.3 Partially opening a window in the furnace or appli-ance room, if available. Keeping the door nearest the applianceroom open at all times or putting louvers in the door.5.5.3.4 P
47、roviding increased makeup air for the appliance(for example, by providing a small duct or opening to theoutdoors near the appliance).5.5.4 If remedial actions are not successful, then consider-ation can be given to correcting or replacing the venting systemor, if necessary, replacing the spilling ap
48、pliance with one thatcan better tolerate house depressurization.5.6 The understanding related to backdrafting and spillagephenomena is evolving. Comprehensive research using asingle, reliable method is needed to better understand thefrequency, duration, and severity of depressurization-inducedspilla
49、ge in a broad cross section of homes (5). In the absenceof a single well-accepted method for assessing the potential foror occurrence of backdrafting or spillage, alternative methodsare presented in this guide. The guide is intended to fosterconsistent application of these methods in future field work orresearch. The resultant data will enable informed decisions onrelative strengths and weaknesses of the different methods andprovides a basis for any refinements that may be appropriate.Continued efforts along these lines will enable the developmentof specifica
