1、Designation: E2342 10Standard Test Method forDurability Testing of Duct Sealants1This standard is issued under the fixed designation E2342; 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 pare
2、ntheses indicates the year of last reapproval. Asuperscript epsilon () 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 registers,
3、plenums, or branches in the duct system. At each ofthese connections a method of sealing the duct system is required. Typical sealing methods includetapes or mastics applied around the joints in the system. Field examinations of duct systems havetypically shown that these seals tend to fail over ext
4、ended 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 conditio
5、ns 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 se
6、alants 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 Sec
9、tion 7.2. Referenced Documents2.1 ASTM Standards:2E631 Terminology of Building Constructions3. Terminology3.1 Terminology E631 defines much of the terminologyused in this test method.3.2 Definitions of Terms Specific to This Standard:3.2.1 air-leakage ratethe volume of air movement perunit time acro
10、ss the duct wall.3.2.2 duct sealanta method or material, or both, forsealing leaks in forced air thermal distribution duct systems.3.2.3 durabilitythe capability of maintaining the service-ability of a product, component, or assembly over a specifiedtime.4. Summary of Test Method4.1 To evaluate seal
11、ant durability this test method uses astandardized joint configuration with controlled temperatureand pressure differences. These temperatures and pressures are1This test method is under the jurisdiction of ASTM Committee E06 onPerformance of Buildings and is the direct responsibility of Subcommitte
12、e E06.41on Air Leakage and Ventilation Performance.Current edition approved March 1, 2010. Published April 2010. Originallyapproved in 2003. Last previous edition approved in 2003 as E2342 03. DOI:10.1520/E2342-10.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM C
13、ustomer 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 Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.chosen to represent conditions f
14、ound in residential duct sys-tems. The test apparatus applies temperature and pressureconditions and measures how well the sealant performs overtime.5. Significance and Use5.1 Residential duct systems are often field designed andassembled. There are many joints, often of dissimilar materialsthat req
15、uire both mechanical connection and air sealing.Without this sealing, duct systems would be extremely leakyand hence inefficient. While some duct sealants are rated ontheir properties at the time of manufacture or during storage,none of these ratings adequately addresses the in-servicelifetime. This
16、 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 includes duct tape (cloth, metal foil,or plastic backed), mastics, and sprayed/aerosol sealants. Itdoes not apply to caulks or plaster patches that
17、are not intendedto be 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 8 in.) indiameter. This perpendicular connection was chosen becausealmost all residential duct systems have this type of connectionand in fiel
18、d 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 requiredapparatus. Any arrangement of equipment using the sameprinciples and capable of performing the test procedure withinthe allowable toleranc
19、es 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 durability test apparatus (Fig. 2).6.2.1 Test Section Leakage Measuring DeviceA devicefor measuring the leakage of individual test sections. Th
20、isdevice 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 measuring 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 sect
21、ion. 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 measured flow, whichever is greater.6.2.2 Durability Test ApparatusA device for blowing hotair through one or more test sections. This device is co
22、mprisedof the following components.FIG. 1 Schematic of Durability ApparatusE2342 1026.2.2.1 Air-Moving EquipmentA fan that is capable ofmoving air through the test sections. The fan must be selectedto provide the required flow rates and pressure differences. Inaddition, the fan must be selected to b
23、e 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 (0.0008 in. of water) or 61 % of the measuredpressure, whichever is greater.6.2.2.3 Temperature-Me
24、asuring 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 thesensor and the test section.6.3 Test SectionSheet metal duct system componentscombined to c
25、reate 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 between 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 u
26、sed to mechanically connect the collar to the flange. SeeFig. 3.7. 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 personn
27、el.7.2 Safety ClothingUse safety 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, andpulleys and to prevent accidental access to any moving parts ofthe equipmen
28、t.7.4 Noise ProtectionMake hearing 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-t
29、ion of the test space or other appropriate 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 m
30、etalscrews.8.2 The test sections shall 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
31、test section and airflowmeter between 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
32、 thatthe cap on the end of test section 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) (
33、0.75 to 1.0 cfmper in.) of perimeter 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
34、of 8.2.1 with the sealed section. 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, dir
35、t,and excess lubricants used in the manufacture of many sheetmetal duct fittings. To ensure removal of oil residue, theFIG. 2 Schematic of Apparatus for Measuring Leakage of Test SectionsE2342 103surfaces should be cleaned using an appropriate solvent. Agood practice is to photograph each test secti
36、on before testingto document how the sealant was originally applied. Record theinitial leakage flow at 25 Pa (0.1 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 leaka
37、ge test.8.3 Place the test sections in the durability testing apparatus.Record the date and time of the placement 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
38、The durability test apparatus shall be constructed andoperated to meet the following parameters:8.5.1 The static 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 outs
39、ide.8.5.2 The test section surface temperature shall be con-trolled to be within the range of 82 to 93C (180 to 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
40、ultraviolet radiation (for example, sunlight) isminimized.8.5.4 The apparatus shall be as airtight as possible with 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
41、ofadmitting make-up air when leakage occurs at a test section.Some duct sealants fail suddenly with a complete loss 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 all
42、ows the time ofcatastrophic failures to be recorded.8.5.5 The following parameters shall be continuously moni-tored 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 sectio
43、nand its surroundings, and8.5.5.3 Air flow through makeup air hole(s).8.5.6 These parameters shall be recorded every hour oftesting for each sample as follows:8.5.6.1 Temperatures: the minimum, maximum, and aver-age for each hour;8.5.6.2 Pressures: the minimum, maximum, and average foreach hour; and
44、8.5.6.3 Makeup air flow: maximum for the hour.9. Data Analysis and Calculations9.1 The weekly leakage measurement, Qleak, 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 Qinit
45、ial. The sealant failureFIG. 3 Schematic of Typical Test Section AssemblyE2342 104criterion is when the increase in leakage above Qinitialreaches10 % of this value, that is:Qleak. 0.1 Qunsealed2 Qinitial! 1 Qinitial# (1)9.1.1 The time to failure shall be the difference between thetime the sample was
46、 placed in the durability test apparatus andthe time at which it failed. This is typically measured in days.9.2 When a catastrophic failure is detected by the monitor-ing system, the time of failure shall be recorded. The failed testsection shall be identified and tested immediately upon failure.9.3
47、 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 and pressure differences for the testsection during the test from the recorded data.10. Reporting Requirements10.1 Users of this test m
48、ethod shall provide the followinginformation for each test section:10.1.1 Test section description: type of sealant (mastic, tapeetc.), manufacturer of sealant, manufacturers identifying code,or manufacturers description for sealant, lot, and batch num-bers (if available);10.1.2 Date and time of tes
49、t start;10.1.3 Date and time of failure10.1.4 Total time before failure (expressed in days andhours). The smallest unit of time used to express time beforetest section failure shall be one hour;10.1.5 A plot of leakage versus time; and10.1.6 Mean, maximum, and minimum surface tempera-tures and pressure differences for the test section duringtesting.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 P
