ASTM E1258-1988(2018) Standard Test Method for Airflow Calibration of Fan Pressurization Devices.pdf

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1、Designation: E1258 88 (Reapproved 2018)Standard Test Method forAirflow Calibration of Fan Pressurization Devices1This standard is issued under the fixed designation E1258; 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 covers the airflow measurement cali-bration techniques for fan pressurization systems used formeasur

3、ing air leakage rates through building envelopes.1.2 This test method is applicable to systems used for airleakage measurement as described in Test Method E779.1.3 This test method involves the installation of the fanpressurization system in a calibration chamber. Use of the fanpressurization system

4、 in an actual building may introduceadditional errors in the airflow measurement due to operatorinfluence, interference of internal partitions and furnishings,weather effects, and other factors.1.4 The proper use of this test method requires a knowledgeof the principles of airflow and pressure measu

5、rement.1.5 This standard includes two basic procedures, a preferredprocedure, based onASHRAE 51AMCA 210, and an optionalprocedure based on a nonstandard airflow measurementtechnique, commonly used by manufacturers of fan pressur-ization devices, but which has not been compared withstandard airflow m

6、easurement techniques.1.6 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.7 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 stan

7、dard to establish appro-priate safety, health, and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.8 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision o

8、n 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 ConstructionsE779 Test Method for DeterminingAir Leakage R

9、ate by FanPressurization2.2 American Society of Heating, Refrigerating, and Air-Conditioning Engineers Standard:3ASHRAE 51AMCA 210 Laboratory Methods for TestingFans for Rating2.3 American Society of Mechanical Engineers Standard:4ASME MFC-3M Standard Measurement of Fluid Flow inPipes Using Orifice,

10、 Nozzle, and Venturi3. Terminology3.1 DefinitionsFor definitions used in this test method,see Terminology E631.3.2 Definitions of Terms Specific to This Standard:3.2.1 ambient conditions, nconditions in the space fromwhich air is drawn into the calibration chamber and into whichthe chamber air is ex

11、pelled.3.2.2 chamber, nan enclosure of rectangular or circularcross section to simulate the entrance and exit conditions thatthe fan is expected to encounter in service.3.2.3 fan air density, ndensity of air at the fan inletexpressed in kilograms per cubic metre.3.2.4 fan airflow rate, nvolumetric a

12、irflow rate at the fanair density expressed in cubic metres per second.3.2.5 fan outlet area, ngross inside area measured in theplane of the fan outlet opening expressed in square metres.3.2.6 fan pressure difference, nthe static pressure differ-ence between two stations expressed in pascals, measur

13、edusing the static pressure taps described in Fig. 1. One station is1This 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 1, 2018. Pu

14、blished July 2018. Originally approvedin 1988. Last previous edition approved in 2012 as E1258 88 (2012). DOI:10.1520/E1258-88R18.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume informat

15、ion, refer to the standards Document Summary page onthe ASTM website.3Available from American Society of Heating, Refrigerating, and Air-Conditioning Engineers, Inc. (ASHRAE), 1791 Tullie Circle, NE, Atlanta, GA30329, http:/www.ashrae.org.4Available from American Society of Mechanical Engineers (ASM

16、E), ASMEInternational Headquarters, Two Park Ave., New York, NY 10016-5990, http:/www.asme.org.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 prin

17、ciples 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) Committee.1located within the chamber between the fan and the nearestflow conditioner

18、s. The other station is outside the chamber.3.2.7 fan pressurization system, na device for measuringthe air leakage rate of a building envelope under controlledpressurization or depressurization of the building interior. Thesystem includes controllable air-moving equipment, an airflowrate measuring

19、system, and a device for measuring the pressuredifference across the building envelope. Such a system is oftenreferred to as a blower door.3.2.8 fan signal, nan output from a fan pressurizationsystem (other than fan speed) that is related to fan airflow rateby the system calibration, such as the sta

20、tic pressure differenceacross a constriction that is integral to the system.3.2.9 fan speed, nspeed of rotation of the fan impellerexpressed in inverse seconds.3.2.10 flow conditioners, na combination of screens orperforated plates located within the calibration chamber toreduce pressure disturbance

21、s within the chamber.3.2.11 nozzle, na gradually tapered constriction, of veryprecise elliptical shape, used in airflow rate measurement (seeFig. 2).3.2.12 nozzle chamber pressure difference, nstatic pres-sure difference measured across a nozzle or bank of nozzleswhen nozzles are installed in a cham

22、ber expressed in pascals.3.2.13 nozzle throat diameter, ndiameter of nozzle dis-charge end expressed in square metres.3.2.14 nozzle throat pressure difference, nstatic pressuredifference across the nozzle in a duct measured with throat tapsexpressed in pascals (see Fig. 2).3.2.15 orifice, na sharp-e

23、dged circular constriction used inairflow measurement (see Fig. 3).3.2.16 orifice pressure difference, nstatic pressure differ-ence measured across an orifice when the orifice is installed ina chamber expressed in pascals.FIG. 1 Static Pressure Tap SpecificationsNozzle with throat taps Nozzle withou

24、t throat tapsNOTE 1Nozzle throat dimension L shall be either 0.6 Dn6 0.005 Dn(recommended) or 0.5 Dn6 0.005 Dn.NOTE 2Nozzle shall have elliptical section as shown. Two and three radii approximations to the elliptical form that do not differ at any point in thenormal direction more than 1.5 % Dnfrom

25、the elliptical form may be used. The outlet edge of the nozzle shall be square, sharp, and free from burrs, nicks,or roundings.NOTE 3The nozzle throat shall be measured (to an accuracy of 0.001 Dn) at the minor axis of the ellipse and the nozzle exit. At each place, fourdiameters, approximately 45 a

26、part must be within 60.002 Dnof the mean. At the entrance to the throat the mean may be 0.002 Dngreater, but no lessthan the mean at the nozzle exit.NOTE 4The nozzle surface shall fair smoothly so that a straightedge may be rocked over the surface without clicking and the surface waves shallnot be g

27、reater than 0.001 Dnpeak to peak.NOTE 5When nozzles are used in a chamber, either of the types shown above may be used. Where a nozzle discharges directly to a duct, nozzleswith throat taps shall be used, and the nozzle outlet should be flanged.NOTE 6Throat tap nozzles shall have four static pressur

28、e taps 90 apart connected to a piezometer ring.FIG. 2 Nozzle SpecificationsE1258 88 (2018)23.2.17 revolution-per-minute (r/min) door, na fan pressur-ization system with a calibration that relates the fan airflow rateto the fan speed.3.2.18 signal door, na fan pressurization system with acalibration

29、that relates the fan airflow rate to an output signalother than fan speed.3.2.19 transformation piece, nan element to connect aduct with a measuring station to a fan when the fan connectionis a different size than the duct (see Fig. 4).4. Summary of Test Method4.1 This test method contains two proce

30、dures for calibratingfan pressurization devices, a preferred procedure based onASHRAE 51AMCA 210, and an optional procedure employ-ing an orifice in a chamber.4.2 Both procedures involve the installation of the fanpressurization system in a chamber.4.3 The calibration consists of a comparison of the

31、 airflowrate through the fan pressurization system measured by thesystem itself, and the airflow rate measured in the calibrationfacility. In the preferred procedure, three modes of airflowmeasurement are acceptable: (1) a nozzle or bank of nozzles inthe chamber, (2) a traverse in a duct using a pit

32、ot tube (see Fig.5), and (3) a nozzle in a duct. Other airflow rate measurementtechniques in a duct can be used such as orifice plates (ASMEMFC-3M) or constant injection tracer gas methods.5In orderfor an alternative airflow rate measurement technique to beincluded as a preferred procedure, the erro

33、rs introduced by theprocedure must be demonstrated not to exceed those intro-duced by a nozzle or pitot traverse. In the optional procedure,the airflow is measured with a series of sharp-edged orificesinstalled in the wall of the chamber.4.4 The calibration must include measurement points thatcover

34、a specific range in both fan pressure difference and fanairflow rate.5Persily, A. K., “Air Flow Calibration of Building Pressurization Devices,”NBSIR 84-2849, National Bureau of Standards, 1984.Recommended Plate Thickness, b1.5mmford up to 150 mm2.5mmford up to 300 mm3.2mmford up to 600 mm4.5mmford

35、up to 1200 mmRecommended Edge Thickness, aLess than 0.02 dNOTE 1For thin plates (b 0.02 d), there is no need for beveling theedge of the orifice.FIG. 3 Sharp-Edged Orifice DesignFIG. 4 Transformation PieceNOTE 1Surface finish shall be 1 m or better. The static orifices maynot exceed 1 mm in diameter

36、. The minimum pitot tube stem diameterrecognized under this standard shall be 2.5 mm. In no case shall the stemdiameter exceed130 of the test duct diameter.FIG. 5 Pitot Tube SpecificationsE1258 88 (2018)35. Significance and Use5.1 The fan pressurization procedure provides a relativelyfast evaluation

37、 of the airtightness of building envelopes. Inorder for the accuracy of the test results to be known, theairflow rate measurement technique of the fan pressurizationsystem must be calibrated.5.2 This test method is applicable to fan pressurizationsystems that are installed in an opening in the build

38、ingenvelope, as opposed to pressurization techniques involvingthe mechanical ventilation system of the building.5.3 The technique of pressurization testing of buildings putsspecific requirements on the calibration of fan pressurizationsystems. The calibration must cover the range of fan pressurediff

39、erences (approximately 12.5 to 75 Pa) that is inducedduring pressurization tests. The calibration must also cover arange in fan airflow rates corresponding to the range inbuilding size and airtightness that the fan pressurization systemwill encounter in the field.5.4 The fan pressurization system mu

40、st be calibrated in bothdirections of airflow used to pressurize and depressurize abuilding if the system airflow direction is reversible. These twocalibrations can be conducted using the various setups de-scribed in this test method; however some of the setups can becombined such that a single cali

41、bration facility can be used tocalibrate the fan in both directions. Such a single setup mayinvolve moving the fan pressurization system from one end ofthe chamber to the other, reversing the orientation of thesystem at the same end of the chamber, or it may not requiremoving the system at all.5.5 T

42、he calibration technique is applicable to the two basictypes of fan pressurization systems in use, r/min doors andsignal doors.5.6 For fan pressurization systems that operate in multipleranges of airflow rate, the system must be calibrated in eachrange.5.7 The calibration technique is intended to pr

43、ovide acomplete calibration of a fan pressurization system. Aftercalibrating several systems of an identical or similar design, thefan airflow rate may be found to be independent of certainparameters such as fan pressure difference. Other simplifyingrelations between fan airflow rate and fan speed o

44、r fan signalmay be observed. If these relations are observed, a manufac-turer or other calibrator may choose to simplify the calibrationprocedure by reducing the number of calibration points.5.8 The use of fan pressurization systems in actual buildingsintroduces additional factors that may cause err

45、ors in theairflow rate measurement that are not accounted for by thecalibration. These factors include operator and weather effectsand interference from internal partitions and other obstructions.6. Hazards6.1 Provide secure guards and cages for fans and motors toprevent accidental contact with any

46、moving parts of theequipment.6.2 When the calibration is being conducted, a large volumeof air is being drawn into and forced out of the apparatus.Exercise care to prevent any objects from being knocked downor blown around the test area.6.3 Noise may be generated by the moving air. Makehearing prote

47、ction equipment available for personnel involvedin the testing.6.4 Design the ducts, chamber, and other equipment utilizedto withstand the pressure and other forces to be encountered.7. Apparatus7.1 The calibration facility must include the followingcomponents:7.1.1 Preferred Procedure:7.1.1.1 Chamb

48、erAn enclosure of rectangular or circularcross section with characteristic dimension, M. In the case of arectangular cross section, the height H shall be at least 2.1 m,the width W shall be at least 2.4 m, and M is given by =4HW/.In the case of a circular cross section, the chamber diametershall be

49、at least 2.5 m and M is equal to the chamber diameter.When multiple nozzles are used in a chamber, the chambermust be large enough to accommodate all the nozzles asdescribed in 7.1.2.1 and 7.1.2.2.7.1.1.2 Flow ConditionersA combination of screens orperforated plates located in the chamber to reduce pressuredisturbances within the enclosure. These air to be locatedwithin the chamber in accordance with 7.1.2. Where a mea-suring plane is located downstream of the flow conditioners,the flow conditioners are provided to ensure a substantiallyunif