1、Designation: E 2342 03Standard Test Method forDurability Testing of Duct Sealants1This standard is issued under the fixed designation E 2342; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in pa
2、rentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.INTRODUCTIONDuct leakage has been identified as a major source of energy loss in residential buildings. Most ductleakage occurs at the connections to register
3、s, plenums or branches in the duct system.At each of theseconnections a method of sealing the duct system is required. Typical sealing methods include tapes ormastics applied around the joints in the system. Field examinations of duct systems have typicallyshown that these seals tend to fail over ex
4、tended periods of time.The proposed method evaluates the durability of duct sealants by blowing heated air into testsections, combined with a pressure difference between the test sections and their surroundings. Thetemperatures and pressures were chosen to expose the test sections to typical conditi
5、ons that are foundin residential duct systems. The duct leakage site geometry represents a leakage site commonly foundin duct systems. The test sections are constructed from standard duct fittings.1. Scope1.1 This test method describes an accelerated aging test forevaluating the durability of duct s
6、ealants by exposure totemperatures and static pressures characteristic of residentialduct systems.1.2 This test method is intended to produce a relativemeasure of the durability of duct sealants. This standard doesnot measure durability under specific conditions of weather andbuilding operation that
7、 might be experienced by an individualbuilding and duct system. Instead it evaluates the sealantmethod under fixed conditions that do not include the manifoldeffects of installation practice.1.3 This test method only addresses sealants not mechanicalstrength of the connections.1.4 This standard does
8、 not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use. For specific hazardstatements see Se
9、ction 7.2. Referenced Documents2.1 ASTM Standards:2E 632 Practice for Developing Accelerated Tests to AidPrediction of the Service Life of Building Components andMaterials3. Terminology3.1 Practice E 632 defines much of the terminology used inthis standard.3.2 Definitions of Terms Specific to This S
10、tandard:3.2.1 air-leakage ratethe volume of air movement perunit time across the duct wall.3.2.2 duct sealanta method and/or material for sealingleaks in forced air thermal distribution duct systems.4. Summary of Test Method4.1 To evaluate sealant durability this test method uses astandardized joint
11、 configuration with controlled temperatureand pressure differences. These temperatures and pressures arechosen to represent conditions found in residential duct sys-tems. The test apparatus applies temperature and pressureconditions, and measures how well the sealant performs overtime.5. Significanc
12、e and Use5.1 Residential duct systems are often field designed andassembled. There are many joints, often of dissimilar materialsthat require both mechanical connection and air sealing.Without this sealing, duct systems would be extremely leakyand hence inefficient. While some duct sealants are rate
13、d ontheir properties at the time of manufacture or during storage,1This test method is under the jurisdiction of ASTM Committee E06 onPerformance of Buildings and is the direct responsibility of Subcommittee E06.41on Air Leakage and Ventilation Performance.Current edition approved Dec. 1, 2003. Publ
14、ished February 2004.2For 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 to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr H
15、arbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.none of these ratings adequately addresses the in-servicelifetime. This test method has been developed to address thisdurability issue.5.2 This standard applies to products which list duct sealingas one of their uses. This inc
16、ludes duct tape (cloth, metal foilor plastic backed), mastics and sprayed/aerosol sealants. It doesnot apply to caulks or plaster patches that are not intended tobe permanent duct sealing methods.5.3 The standard duct leak site is a collar to plenumconnection for round duct that is 10 to 20 cm (4 to
17、 8 in.) indiameter. This perpendicular connection was chosen becausealmost all residential duct systems have this type of connectionand in field observations of duct systems, it is often this type ofconnection that has sealant failure.6. Apparatus6.1 The following is a general description of the req
18、uiredapparatus. Any arrangement of equipment using the sameprinciples and capable of performing the test procedure withinthe allowable tolerances is permitted.6.2 Major ComponentsThere are two major componentsrequired to perform the testing: a test section leakage measure-ment device (Fig. 1) and a
19、durability test apparatus (Fig. 2).6.2.1 Test Section Leakage Measuring DeviceA devicefor measuring the leakage of individual test sections. Thisdevice shall consist of a fan to blow air into the test section, aflow measurement device for measuring the flow rate in the testsection, a pressure measur
20、ing device for measuring the pres-sure difference between the inside and outside of the testsection, and a cap to seal the end of the test section. See Fig.2. For these test section leakage measurements, the air flowmeasuring device shall have an accuracy of 60.085 m3/h (0.05cfm) or 61 % of the meas
21、ured flow, whichever is greater.6.2.2 Durability Test ApparatusA device for blowing hotair through one or more test sections. This device is comprisedof the following components.6.2.2.1 Air-Moving EquipmentA fan that is capable ofmoving air through the test sections. The fan must be selectedto provi
22、de the required flow rates and pressure differences. Inaddition, the fan must be selected to be capable of operating atthe hot conditions existing in the test apparatus.6.2.2.2 Pressure-Measuring DevicesManometers or pres-sure indicators to measure pressure difference with an accuracyof 60.2 Pa (0.0
23、008 in. of water) or 61 % of the measuredpressure, whichever is greater.6.2.2.3 Temperature-Measuring DevicesInstruments tomeasure temperature with an accuracy of 61C (2F). The testsection surface temperatures shall be measured using surfacemount temperature sensors with heat transfer paste between
24、thesensor and the test section.FIG. 1 Schematic of Durability ApparatusE23420326.3 Test SectionSheet metal duct system componentscombined to create a plenum to collar connection. The testsection consists of a flange and a collar with fingers to fold inand out of the hole in the flange. The gap betwe
25、en the flangeand the collar shall be 6 mm (14 in.) all the way around. Thecollar shall be centered in the flange. Sheet metal screws shallbe used to mechanically connect the collar to the flange. SeeFig. 3.FIG. 2 Schematic of Apparatus for Measuring Leakage of Test SectionsFIG. 3 Schematic of Typica
26、l Test Section AssemblyE23420337. Hazards7.1 Eye ProtectionDucts should not break at the pressuredifferences normally applied to the test structure. However, foradded safety, adequate precautions such as the use of eyeprotection should be taken to protect the personnel.7.2 Safety ClothingUse safety
27、equipment required forgeneral laboratory work, including safety shoes, and workgloves.7.3 Equipment GuardsThe air-moving equipment shallhave a proper guard or cage to house the fan, motor and pulleysand to prevent accidental access to any moving parts of theequipment.7.4 Noise ProtectionMake hearing
28、 protection availablefor personnel who must be close to the noise that may begenerated by the fan.7.5 Debris and FumesDuct materials may decomposeduring the test releasing particles and fumes into the air.Adequate protection must be provided in the form of ventila-tion of the test space or other app
29、ropriate means.8. Procedure8.1 Construct test sections of the plenum to collar joint typeshown in Fig. 3. The test sections shall use ducts of 100 to 200mm (4 to 8 in.) diameter round sheet metal. The sheet metalsections shall be mechanically connected using sheet metalscrews.8.2 The test sections s
30、hall be tested for their air leakagebefore and after they are sealed. The temperature of air flowingthrough the test section and flowmeter shall be measured andthe leakage tests for the test sections shall be performed withthe temperature of air flowing through the test section and airflowmeter betw
31、een 15 and 25C (59 and 77F). All measuredair flows shall be corrected to standard conditions usinginstructions provided by the air flowmeter manufacturer.8.2.1 Connect the unsealed test section to the test sectionleakage measurement device as shown in Fig. 2. Ensure thatthe cap on the end of test se
32、ction and all other connections aresealed. Pressurize the test section to 25 Pa (0.1 in. water) andrecord the flow through the flowmeter. This is the unsealed testsection leakage Qunsealed. The acceptable range for this un-sealed leakage is 0.050 to 0.067 m3/(hmm) (0.75 to 1.0 cfmper in.) of perimet
33、er of the test section plenum to collarconnection. If the test section is outside this range it needs tobe rebuilt and the hole size adjusted until it meet this criteria,or not used for testing.8.2.2 Apply the sealant to the test section and perform theleakage test of 8.2.1 with the sealed section.
34、The sealant shallbe applied using manufacturers instructions. If no instructionscome with the sealant, then the sealant shall be applied ascarefully as possible. This careful application includes ensur-ing that surfaces to be sealed are clean and free from dust, dirtand excess lubricants used in the
35、 manufacture of many sheetmetal duct fittings. To ensure removal of oil residue, thesurfaces should be cleaned using an appropriate solvent. Agood practice is to photograph each test section before testingto document how the sealant was originally applied. Record theinitial leakage flow at 25 Pa (0.
36、1 in. water), Qinitial.IfQinitialisgreater than 2 % of Qunsealedthen the initial sealing is inad-equate and the test section shall not be used. Record the dateand time of the initial leakage test.8.3 Place the test sections in the durability testing apparatus.Record the date and time of the placemen
37、t of the test section inthe apparatus.8.4 The test sections shall be removed from the durabilityapparatus on a weekly basis to have the leakage test in 8.2.1performed to measure Qleak.8.5 The durability test apparatus shall be constructed andoperated to meet the following parameters:8.5.1 The static
38、 pressure difference between the inside of thetest section and its surroundings shall be 200 Pa 6 20 Pa (0.86 0.08 in. of water), with the air inside the duct at a higherpressure than outside.8.5.2 The test section surface temperature shall be con-trolled to be within the range of 82 to 93C (180 to
39、200F)measured on the outside surface of the test section within 5 cm(2 in.) of the gap between the flange and the collar.8.5.3 The test sections shall be enclosed so that theirexposure to ultraviolet radiation (for example, sunlight) isminimized.8.5.4 The apparatus shall be as airtight as possible w
40、ith anintentional hole added on the suction side of the air movingfan. The intentional hole shall be continuously monitored formake-up air flow rate. The monitored hole is for the purpose ofadmitting make-up air when leakage occurs at a test section.Some duct sealants fail suddenly with a complete l
41、oss of sealon the test section. This is called catastrophic failure. Whencatastrophic failure of the test seal occurs, an abrupt increase inmake-up air flow will occur. This monitoring allows the time ofcatastrophic failures to be recorded.8.5.5 The following parameters shall be continuously moni-to
42、red at a sampling frequency of once every ten seconds (ormore often if desired).8.5.5.1 Surface temperature of each test section,8.5.5.2 Pressure difference between inside each test sectionand its surroundings, and8.5.5.3 Air flow through makeup air hole(s).8.5.6 These parameters shall be recorded e
43、very hour oftesting for each sample as follows:8.5.6.1 Temperatures: the minimum, maximum and averagefor each hour,8.5.6.2 Pressures: the minimum, maximum and average foreach hour, and8.5.6.3 Makeup air flow: maximum for the hour.9. Data Analysis and Calculations9.1 The weekly leakage measurement, Q
44、leak, for each testsection shall be compared to the air leakage reduction providedby the seal; that is, the difference between unsealed leakage,Qunsealed, and the initial leakage Qinitial. The sealant failurecriterion is when the increase in leakage above Qinitialreaches10 % of this value, that is:Q
45、leak. 0.1 Qunsealed2 Qinitial! 1 Qinitial# (1)9.1.1 The time to failure shall be the difference between thetime the sample was placed in the durability test apparatus andthe time at which it failed. This is typically measured in days.E23420349.2 When a catastrophic failure is detected by the monitor
46、-ing system, the time of failure shall be recorded. The failed testsection shall be identified and tested immediately upon failure.9.3 A plot of weekly (and final) leakage versus time shall bemade. An example is given in Fig. 4 .9.4 Obtain the mean, maximum and minimum recordedsurface temperatures a
47、nd pressure differences for the testsection during the test from the recorded data.10. Reporting Requirements10.1 Users of this test method shall provide the followinginformation for each test section:10.1.1 Test section description: type of sealant (mastic, tapeetc.), manufacturer of sealant, manuf
48、acturers identifying codeor manufacturers description for sealant, lot and batch numbers(if available),10.1.2 Date and time of test start,10.1.3 Date and time of failure,10.1.4 Total time before failure (expressed in days andhours). The smallest unit of time used to express time beforetest section f
49、ailure shall be one hour,10.1.5 A plot of leakage versus time, and10.1.6 Mean, maximum and minimum surface temperaturesand pressure differences for the test section during testing.10.2 The following information shall be provided as onoption for information and further analysis purposes:10.2.1 Leakage flows at 25 Pa (0.1 in. water), Qunsealed,Qsealed, Qleak.11. Precision and Bias11.1 PrecisionThe precision of the procedure in TestMethod E 2342 for durability testing of duct sealant methods isestimated from the accuracy specifications for the measure-ment equip
