ASTM E779-2010(2018) 8125 Standard Test Method for Determining Air Leakage Rate by Fan Pressurization.pdf

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1、Designation: E779 10 (Reapproved 2018)Standard Test Method forDetermining Air Leakage Rate by Fan Pressurization1This standard is issued under the fixed designation E779; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of

2、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 test method measures air-leakage rates through abuilding envelope under controlled pressurization and de-pressuri

3、zation.1.2 This test method is applicable to small temperaturedifferentials and low-wind pressure differential, thereforestrong winds and large indoor-outdoor temperature differen-tials shall be avoided.1.3 This test method is intended to quantify the air tightnessof a building envelope. This test m

4、ethod does not measure airchange rate or air leakage rate under normal weather conditionsand building operation.NOTE 1See Test Method E741 to directly measure air-change ratesusing the tracer gas dilution method.1.4 This test method is intended to be used for measuringthe air tightness of building e

5、nvelopes of single-zone buildings.For the purpose of this test method, many multi-zone buildingscan be treated as single-zone buildings by opening interiordoors or by inducing equal pressures in adjacent zones.1.5 Only metric SI units of measurement are used in thisstandard. If a value for measureme

6、nt is followed by a value inother units in parentheses, the second value may be approxi-mate. The first stated value is the requirement.1.6 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 es

7、tablish appro-priate safety, health, and environmental practices and deter-mine the applicability of regulatory limitations prior to use.For specific hazard statements see Section 7.1.7 This international standard was developed in accor-dance with internationally recognized principles on standard-iz

8、ation established in the Decision on Principles for theDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2E631 Terminology of Building ConstructionsE741 Test

9、Method for Determining Air Change in a SingleZone by Means of a Tracer Gas DilutionE1258 Test Method for Airflow Calibration of Fan Pressur-ization Devices3. Terminology3.1 For definitions of terms used in this test method, refer toTerminology E631.3.2 Definitions of Terms Specific to This Standard:

10、3.2.1 air-change rate, nair-leakage rate in volume units/hdivided by the building space volume with identical volumeunits, normally expressed as air changes/h, ACH.3.2.2 air-leakage, nthe movement/flow of air through thebuilding envelope, which is driven by either or both positive(infiltration) and

11、negative (exfiltration) pressure differencesacross the envelope.3.2.3 air-leakage graph, nthe graph that shows the rela-tionship of measured airflow rates to the corresponding mea-sured pressure differences, plotted on a log-log scale.3.2.4 air-leakage rate, nthe volume of air movement/unittime acro

12、ss the building envelope including airflow throughjoints, cracks, and porous surfaces, or a combination thereofdriven by mechanical pressurization and de-pressurization,natural wind pressures, or air temperature differentials betweenthe building interior and the outdoors, or a combinationthereof.3.2

13、.5 building envelope, nthe boundary or barrier separat-ing different environmental conditions within a building andfrom the outside environment.3.2.6 effective leakage area, nthe area of a hole, with adischarge coefficient of 1.0, which, witha4Papressuredifference, leaks the same as the building, al

14、so known as thesum of the unintentional openings in the structure.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 July 15, 2018. Pub

15、lished July 2018. Originallyapproved in 1981. Last previous edition approved in 2010 as E779 10. DOI:10.1520/E0779-10R18.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refe

16、r to the standards Document Summary page onthe ASTM website.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with internationally recognized principles on standardization establish

17、ed in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.13.2.7 height, building, nthe vertical distance from gradeplane to the average height of the highest ceiling s

18、urface.3.2.8 interior volume, ndeliberately conditioned spacewithin a building, generally not including attics and attachedstructures, for example, garages, unless such spaces are con-nected to the heating and air conditioning system, such as acrawl space plenum.3.2.9 single zone, na space in which

19、the pressure differ-ences between any two places, differ by no more than 5 % ofthe inside to outside pressure difference including multi-roomspace that is interconnected within itself with door-sizedopenings through any partitions or floors where the fan airflowrate is less than 3 m3/s (6 103ft3/min

20、).3.2.10 test pressure difference, nthe measured pressuredifference across the building envelope, expressed in Pascals(in. of water or pounds-force/ft2or in. of mercury).3.3 Symbols and UnitsSee Table 1.4. Summary of Test Method4.1 This test method consists of mechanical pressurizationor de-pressuri

21、zation of a building and measurements of theresulting airflow rates at given indoor-outdoor static pressuredifferences. From the relationship between the airflow ratesand pressure differences, the air leakage characteristics of abuilding envelope are determined.5. Significance and Use5.1 Air leakage

22、 accounts for a significant portion of thethermal space conditioning load. In addition, it affects occupantcomfort and indoor air quality.5.2 In most commercial or industrial buildings, outdoor airis often introduced by design; however, air leakage is asignificant addition to the designed outdoor ai

23、rflow. In mostresidential buildings, indoor-outdoor air exchange is attribut-able primarily to air leakage through cracks and constructionjoints and is induced by pressure differences due to temperaturedifferences, wind, operation of auxiliary fans (for example,kitchen and bathroom exhausts), and th

24、e operation of combus-tion equipment in the building.5.3 The fan-pressurization method is simpler than tracer gasmeasurements and is intended to characterize the air tightnessof the building envelope. It is used to compare the relative airtightness of several similar buildings to identify the leakag

25、esources and rates of leakage from different components of thesame building envelope, and to determine the air leakagereduction for individual retrofit measures applied incrementallyto an existing building, and to determine ventilation rates whencombined with weather and leak location information.6.

26、 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 tolerances shall be permitted.6.2 Major Components:6.2.1 Air-Moving EquipmentFan, blower, HVAC airmove

27、ment component or blower door assembly that is capableof moving air into and out of the conditioned space at requiredflow rates under a range of test pressure differences. Thesystem shall provide constant airflow at each incrementalpressure difference at fixed pressure for the period required toobta

28、in readings of airflow rate.6.2.2 Pressure-Measuring DeviceManometer or pressureindicator to measure pressure difference with an accuracy of65 % of the measured pressure or 0.25 Pa (0.001 in. H2O),whichever is greater.6.2.3 Airflow Measuring SystemDevice to measure air-flow with an accuracy of 65 %

29、of the measured flow. Theairflow measuring system shall be calibrated in accordancewith Test Method E1258.6.2.4 Temperature-Measuring DeviceInstrument to mea-sure temperature with an accuracy of 61 C (2 F).7. Hazards7.1 Eye ProtectionGlass breakage at the building pressuredifferences normally applie

30、d to the test structure is uncommon:however, for added safety, adequate precautions, such as theuse of eye protection shall be taken to protect the personnel.7.2 Safety ClothingUse safety equipment required forgeneral field work, including safety shoes, and hard hats.7.3 Equipment GuardsThe air-movi

31、ng equipment shallhave a proper guard or cage to house the fan or blower and toprevent accidental access to any moving parts of the equip-ment.7.4 Noise ProtectionExposure to the noise level generatedby fans can be hazardous to the hearing of involved personneland hearing protection is required.7.5

32、Debris and FumesThe blower or fan forces a largevolume of air into or out of a building while in operation. Careshall be exercised to not to damage plants, pets, occupants, orinternal furnishings due to influx of cold or warm air. Cautionshall be exercised against sucking debris or exhaust gases fro

33、mfireplaces and flues into the interior of the building. Activecombustion devices shall be shut off or the safety determinedof conducting the test by a properly trained technician beforeconducting the test.8. Procedure8.1 To create a single zone for this test procedure, allinterconnecting doors in t

34、he conditioned space shall be openTABLE 1 Symbols and UnitsSymbol Quantity UnitE Elevation above sea level m ftQ Measured airflow rate m3/s cfmQoAir leakage rate m3/s cfmC Air leakage coefficient m3/(s Pan) cfm/Pan Air density kg/m3lb/ft3T Temperature C Fn Pressure exponent . . .P Pressure Pa lb/ft2

35、dP Induced pressure difference Pa lb/ft2dPrReference pressure difference Pa lb/ft2 Dynamic air viscosity kg/(ms) lb/(fth)A Area m2ft2E779 10 (2018)2such that a uniform pressure shall be maintained within theconditioned space to within 610 % of the measured inside/outside pressure difference. This co

36、ndition shall be verified bydifferential pressure measurements at the highest pressure usedin the test. These measurements shall be taken at the highestceiling elevation and lowest floor elevation of the building andon the windward and leeward sides.8.2 HVAC balancing dampers and registers shall not

37、 beadjusted. Fireplace and other operable dampers shall be closedunless they are used to pass air to pressurize or de-pressurizethe building.8.3 General observations of the condition of the buildingshall be recorded, including appropriate observations of thewindows, doors, opaque walls, roof, and fl

38、oor.8.4 Measure and record the indoor and outdoor tempera-tures at the beginning and the end of the test and average thevalues. If the product of the absolute value of the indoor/outdoor air temperature difference multiplied by the buildingheight, gives a result greater than 200 m C (1180 ft F), the

39、test shall not be performed, because the pressure differenceinduced by the stack effect is too large to allow accurateinterpretation of the results.8.5 Connect the air duct or blower door assembly to thebuilding envelope, using a window, door, or vent opening. Sealor tape openings to avoid air leaka

40、ge at these points.8.6 If a damper is used to control airflow, it shall be in afully closed position for the zero flow pressure measurements.8.7 Installing the Envelope Pressure Sensor(s)Install thepressure measuring device across the building envelope.Where possible, locate the pressure tap at the

41、bottom of theleeward wall. When wind causes adverse pressure fluctuationsit may be advantageous to average the pressures measured atmultiple locations, for example, one across each facade. Fig. 1illustrates preferred locations that avoid extremes of exteriorpressures. A good location avoids exterior

42、 corners and shouldbe close to the middle (horizontally) of the exterior wall.Beware of direct sunlight hitting pressure tubing, especiallyvertical sections.8.8 Measure zero flow pressures with the fan openingblocked. These zero flow envelope pressures shall be measuredbefore and after the flow meas

43、urements. The average over atleast a 10-s interval shall be used. These zero flow pressuresshall be subtracted from the envelope pressures measuredduring pressurization and depressurization.NOTE 2Some equipment may perform this step, or an equivalent step,automatically. Follow the manufacturers inst

44、ructions accordingly.8.9 The range of the induced pressure difference shall befrom 10 to 60 Pa (0.04 to 0.24 in. H2O), depending on thecapacity of the air-moving equipment. Because the capacity ofthe air-moving equipment, the lack of tightness in the building,and the weather conditions affect leakag

45、e measurements, thefull range of the higher values may not be achievable. In suchcases, substitute a partial range encompassing at least five datapoints.NOTE 3It is advisable to check that the condition of the buildingenvelope has not changed after each pressure reading, for example, thatsealed open

46、ings have not become unsealed or that doors, windows, ordampers have not been forced open by the induced pressure.8.10 Use increments of 5 to 10 Pa (0.02 to 0.04 in. H2O) forthe full range of induced pressure differences.8.11 At each pressure difference, measure the airflow rateand the pressure diff

47、erences across the envelope. After the fanand instrumentation have stabilized, the average over at least a10-s interval shall be used.8.12 For each test, collect data for both pressurization andde-pressurization.8.13 Determine the elevation of the measurement site, E (mor ft), above mean sea level w

48、ithin 100 m (330 ft).FIG. 1 Recommended Locations for Exterior Pressures (Plan Views of Buildings“X” Within Circles Mark Pressure Tap Locations)E779 10 (2018)39. Data Analysis and Calculations9.1 Unless the airflow measuring system gives volumetricflows at the barometric pressure and the temperature

49、s of the airflowing through the flowmeter during the test, these readingsshall be converted using information obtained from the manu-facturer for the change in calibration with these parameters.The barometric pressure or air density, if used in theconversions, may be calculated using equations from AppendixX1.9.2 Convert the readings of the airflow measuring system(corrected as in 9.1, if necessary) to volumetric air flows at thetemperature and barometric pressure of the outside air fordepressurization tests or of the i