ASTM E2178-2011 Standard Test Method for Air Permeance of Building Materials《建材航空渗透系数的标准试验方法》.pdf

1、Designation: E2178 11Standard Test Method forAir Permeance of Building Materials1This standard is issued under the fixed designation E2178; 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.1. Scope1.1 This test method is to determine the air permeance ofbuilding materials at various pressure differentials with theintent of determining an assigned a

3、ir permeance rate of thematerial at the reference pressure difference (DP)of75Pa.1.2 The method is intended to assess flexible sheet or rigidpanel-type materials using a 1 m 3 1 m specimen size.1.3 The values stated in SI units are to be regarded asstandard. No other units of measurements are includ

4、ed in thisstandard.1.4 This standard does 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

5、use.2. Referenced Documents2.1 ASTM Standards:2E283 Test Method for Determining Rate of Air LeakageThrough Exterior Windows, Curtain Walls, and DoorsUnder Specified Pressure Differences Across the SpecimenE631 Terminology of Building ConstructionsE1677 Specification for Air Barrier (AB) Material or

6、Sys-tem for Low-Rise Framed Building Walls3. Terminology3.1 Definitions:3.1.1 For definitions of general terms related to buildingconstruction used in this test method, refer to TerminologyE631.3.2 Definitions of Terms Specific to This Standard:3.2.1 air permeancethe rate of air flow (L/s), per unit

7、 area(m2) and per unit static pressure differential (Pa).4. Significance and Use4.1 The purpose of this test is to measure the air permeanceof flexible sheet or rigid panel-type materials. The results ofthis test may be useful in determining suitability of thatmaterial as a component of an air retar

8、der system.4.2 This method does not address the installed air leakageperformance of building materials. The installed performanceof air retarder materials and air retarder systems in low-riseframed wall construction is addressed in Specification E1677.5. Sampling5.1 The number of specimens to be tes

9、ted shall be suitableto establish an air leakage rate which is representative of theproduct. In no case shall less than five specimens be tested.NOTE 1Because of the variability in the manufacture of a product, thenumber of specimens to be tested may vary from product to product.Certain materials ma

10、y have standard methods for sampling that shall beused to sample these materials.6. Test Apparatus6.1 A schematic of the air leakage test apparatus is pre-sented in Fig. 1.6.1.1 Airtight Test ChamberThe airtight test chambershall be at least 320 mm deep and capable of receivinga1mby 1 m test specime

11、n, anchored to the test chamber by meansof a compression frame and clamping devices. The testchamber and compression frame shall be stiff enough to limitdeflection within the operating flexibility of the gaskets used toseal the test specimen to the chamber. Two parallel ribbons ofself-adhesive gaske

12、t material shall be applied at all sealingpoints of the apparatus/test specimen assembly. The gasketribbons shall be made of medium-density gasket material thatcan be fused or glued at joints. The test apparatus shall containan over-pressure control device and windows to verify thespecimen installat

13、ion.6.1.2 Flow Measuring DevicesThe flow measuring de-vices used to gage the air flow through the test specimen shallbe capable of measuring air flow rate from 1 3 10-6m3/s (.001L/s) up to 1.88 3 10-2m3/s (18.8 L/s), with an accuracy of 63 % of the reading.6.1.3 Pressure Measuring DevicesThe static

14、pressure dif-ferential across the test specimen shall be measured by pressuremeasuring devices with an accuracy of 6 0.5 % of the pressure1This test method is under the jurisdiction of ASTM Committee E06 onPerformance of Buildings and is the direct responsibility of Subcommittee E06.41on Air Leakage

15、 and Ventilation Performance.Current edition approved Nov. 1, 2011. Published December 2011. Originallyapproved in 2001. Last previous edition approved in 2003 as E2178 03. DOI:10.1520/E2178-11.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at s

16、erviceastm.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.reading. The laboratory barometric pressure shall be

17、 measuredwith a device capable of measuring barometric pressure within6 3 % of the reading.6.1.4 PipingThe piping connecting the flow measuringdevices and the vacuum blower shall be airtight and containflow control devices to regulate the static pressure across thetest specimen within 60.5 % of the

18、pressure reading. The pipeconnection to the test chamber shall contain an air filter toprevent dust or particulate matter from affecting the flowmeasuring device reading. The piping downstream and up-stream of the flow measuring device shall be designed so theflow regime does not affect the devices

19、accuracy. The pipingshall contain a temperature measuring device capable ofmeasuring air temperature within 60.5C to convert all flowrate measurement to STP.6.1.5 Vacuum BlowerThe blower used to create a vacuumin the test chamber shall be able to produce static pressuredifferential across the test s

20、pecimen within 60.5 % of thepressure reading.7. Specimen Preparation7.1 Conditioning for TestsUnless otherwise stated, allspecimens to be tested shall be conditioned for a minimumperiod of seven days at 21 6 1C and 40 6 5 % RH.7.2 Flexible Sheet MaterialsDue to lack of rigidity, flex-ible materials

21、shall be tested over a rigid support having an airpermeance much greater than the test specimen. An open grillor wire mesh/screen, fabricated with welded wire having aminimum of 25 mm 3 25-mm-square grid (or an alternativemeans that provides an equivalent degree of support and airpermeance) shall be

22、 used for this purpose. The wire meshportion of the support shall be welded or otherwise mechani-cally secured to a solid metal frame which shall be gasketedand compressed within the test frame. A detailed description ofthe support grill, including the gage wire used, shall beincluded in the test re

23、port. Fig. 2 shows the preparation for atypical flexible sheet material. The following procedure shallbe used to seal the perimeter of the specimen:FIG. 1 General Configuration of Test ApparatusE2178 1127.2.1 Apply a self-adhesive gasket ribbon over the frame ofthe wire mesh/screen around the entire

24、 perimeter of the testarea under investigation (1 m 3 1 m);7.2.2 Apply a second self-adhesive gasket ribbon along theperimeter of the first ribbon in 7.2.1;7.2.3 All joints in the gasket ribbons shall be fused or glued;7.2.4 Cut the flexible sheet material specimen to 1100 mm3 1100 mm;7.2.5 Upon rem

25、oval of the protective paper over the self-adhesive gasket, install the specimen over the wire mesh/screen;7.2.6 Apply the self-adhesive gasket over the specimen so itlines up with the first ribbon in 7.2.1, and then apply a secondself-adhesive gasket along its perimeter;7.2.7 All joints in the gask

26、et ribbons shall be fused or glued;FIG. 2 Flexible Sheet Test SpecimenFIG. 3 Top View of Polyethylene Placement Over Specimen with Double Perimeter GasketsE2178 1137.2.8 Cut polyethylene film (0.15 mm (6 mils) to 1400 mm3 1400 mm;7.2.9 Upon removal of the protective paper over the ribbon,cover the s

27、pecimen with the polyethylene film;7.2.10 Cut the polyethylene film at each corner as per Fig. 3;7.2.11 Apply two self-adhesive gaskets to the underside ofthe wire mesh/screen support (the gaskets shall line up belowthe first ribbon installed in 7.2.1);7.2.12 Upon removal of the protective paper ove

28、r thegasket, fold and tape each corner of the film with constructiontape to ensure complete airtightness as per Fig. 4;7.2.13 From the interior line of the adhesive gasket, cut andremove all the excess polyethylene film.7.3 Rigid Panel-Type MaterialsFig. 5 shows the prepara-tion for a typical rigid

29、panel-type material. The followingprocedure shall be used to seal the perimeter of the specimen:7.3.1 Apply a self-adhesive gasket ribbon over the rigidpanel-type test specimen around the entire perimeter of the areaunder investigation (1 m 3 1 m);7.3.2 All joints in the gasket ribbons shall be fuse

30、d or glued;7.3.3 Cut polyethylene film (0.15 mm (6 mils) to 1400 mm3 1400 mm;7.3.4 Upon removal of the protective paper over the self-adhesive gasket ribbon, cover the specimen with the polyeth-ylene film;7.3.5 Cut the polyethylene film at each corner as per Fig. 3;7.3.6 Apply a second self-adhesive

31、 gasket ribbon to theunderside of the specimen (the ribbon shall be applied directlybelow the first ribbon installed in 7.3.1), and seal cornerjunctions by fusing or gluing;7.3.7 Upon removal of the protective paper over the self-adhesive gasket ribbon, fold and tape each corner of the filmwith cons

32、truction tape to ensure complete airtightness as perFig. 4;7.3.8 From the interior line of the self-adhesive gasketribbon, cut and remove all the excess polyethylene film.8. Test Procedure8.1 Control TestsThe laboratory shall confirm the integ-rity and accuracy of the apparatus by verifying the foll

33、owing:8.1.1 The impact of the open mesh/screen on the air leakagerate measurements shall be assessed. If not negligible, it shallbe taken into account when calculating the air permeance.8.1.2 The air leakage rate across one specimen of a 12.5-mm-thick regular gypsum board shall be determined in acco

34、r-dance with procedures outlined in 7.3, for a rigid panel-typematerial. The air leakage rate of the regular gypsum board shallnot exceed 0.02 L/(s m2) at a pressure differential of 75 Pa.8.2 Specimen TestingThe testing on each specimen shallbe conducted as follows:8.2.1 Install the sealed test spec

35、imen on the test chamber;8.2.2 Install the compression frame over the specimen;8.2.3 Check through the window if the specimen is properlyplaced;8.2.4 Anchor the specimen to the test chamber and com-press the gaskets, as required;8.2.5 Measure the extraneous air leakage (Qei) of the testapparatus/spe

36、cimen at various static pressure differentials (DP)as follows: 25, 50, 75, 100, 150 and 300 Pa.8.2.6 Cut the top section of the polyethylene film;8.2.7 Measure the total air leakage (Qti) at various staticpressure differentials (DP), and correct the air flow rate valuesto STP. The air permeance of e

37、ach specimen shall be deter-mined with a minimum of six measurements when conductedin accordance with Test Method E283. The six measurementsshall be taken as follows: 25, 50, 75, 100, 150 and 300 Pa.NOTE 2Acalculation to correct air flow rate values to STP is providedin Section 12.1 of Test Method E

38、283.8.2.8 After measuring the air leakage at the maximum staticpressure differential (DP), 300 Pa, remeasure the air leakage at100, 75, and 50 Pa to determine if the measurement process haseffected the air leakage of the material. If the differenceFIG. 4 Bottom View of Polyethylene Seal at Double-Pe

39、rimeter Gaskets on Underside of Rigid Panel-Type Specimen or Open Mesh/Screen for Flexible Sheet Specimen Set-upE2178 114between the two air leakage measurements is greater than10 %, the cause of the air leakage rate change shall beidentified.9. Calculation of Air Permeance9.1 At each pressure stati

40、on, the flow rate through thespecimen (Q) shall be determined by subtracting the extrane-ous air flow rate (Qei) from the total air leakage (Qti).9.2 The flow rate equation of the form Q 5 CADP!nshallbe established by fitting the data, and errors estimated. Arecommended procedure is provided in Anne

41、x A1.9.3 Calculate the material permeance at the pressure differ-ences measured. The air permeance (P) of a specimen at agiven pressure differential (DP) is calculated by the followingequation.P 5QA!DP!(1)where:Q = flow rate from the flow rate equation (see 9.2),A = specimen cross-sectional area (1

42、m2), andDP = pressure difference.9.4 An error analysis shall be performed that includes anexamination of the sources of error, an evaluation of systematicerrors and propagation of error, and the resulting value of erroron air flow values through the material tested.10. Report10.1 The report shall in

43、clude the following:10.1.1 Identification of the material tested, including thick-ness and basis weight.10.1.2 The material sampling procedure used.10.1.3 The measured air flow versus pressure differencedata in graphic form (log/log graph) for the specimens. The airleakage rate at the reference pres

44、sure difference, DP,of75Pashall be identified on the graph.10.1.3.1 The flow rate equation shall be established throughlinear fitting of data by method of least squares for the pressurereadings. The coefficient of determination (r2) must be calcu-lated and presented. A regression line based on air l

45、eakage datahave a r2 0.99 will not be accepted unless proper explana-tions are given for the deviation. All air leakage rates must beexpressed in L/s/m2.10.1.4 The calculated air permeance versus the pressuredifference in tabular form.10.1.5 The error analysis as described in 9.4.11. Precision and B

46、ias11.1 The precision and bias of the test method have not beendetermined.12. Keywords12.1 air permeance; air retarder; building materials;buildingsFIG. 5 Rigid Panel-Type Specimen Test Set-upE2178 115ANNEX(Mandatory Information)A1. RECOMMENDED PROCEDURE FOR ESTIMATING ERRORS IN DERIVED QUANTITIESA1

47、.1 This test method contains several derived quantitieswhich are often used to summarize the air tightness of thebuilding or component tested. It is important to report anestimate of the error in such quantities. The following methodis recommended: all derived quantities depend on the estima-tion of

48、 the air leakage coefficient C and air pressure exponentn of Eq A1.1. To determine C and n, make a log transformationof the variables Q and dP for each reading.xi5 lndPi! (A1.1)yi5 lnQi!for i 5 1Nwhere:N = total number of test readings.Eq A1.1 then transforms into:y 5 lnC! 1 n x (A1.2)Compute the fo

49、llowing quantities:x51N(i 5 1Nxi(A1.3)y51N(i 5 1Nyi(A1.4)Sx251N 1(i 5 1Nxi x!2(A1.5)Sy251N 1(i 5 1Nyi y!2(A1.6)Sxy51N 1(i 5 1Nxi x! yi y! (A1.7)Then the best estimate of n and ln(C) is given by:n 5SxySx2(A1.8)lnC! 5 y n x(A1.9)C 5 expy n x!(A1.10)The 95 % confidence limits for C and n can be determined asfollows. The variance of n is given by the estimate:Sn51SxSSy2 n SxyN 2D12(A1.11)and the estimate of the variance of ln(C) is given bySlnC!5 SnS(i 5 1Nxi2ND12(A1.12)The confidence limits for ln(C) and n are respecti