EN 12238:2001
(Main)Ventilation for buildings - Air terminal devices - Aerodynamic testing and rating for mixed flow application
Ventilation for buildings - Air terminal devices - Aerodynamic testing and rating for mixed flow application
This European Standard specifies methods for the laboratory aerodynamic testing and rating of air terminal devices for mixed flow applications, including the specification of suitable test facilities and measurement techniques.
The standard gives only tests for the assessment of characteristics of the air terminal devices under isothermal conditions.
The testing of low velocity air terminal devices is specified in EN 12239.
Lüftung von Gebäuden - Luftdurchlässe - Aerodynamische Prüfung und Bewertung für Anwendung bei Mischströmung
Diese Europäische Norm legt Verfahren für die aerodynamische Laborprüfung und Bewertung von Luftdurchlässen für Anwendung bei Mischströmung sowie geeignete Prüfeinrichtungen und Meßverfahren fest. Die Europäische Norm enthält nur Prüfungen zur Feststellung der Kenngrößen der Luftdurchlässe unter isothermischen Bedingungen. Die Prüfung von Luftdurchlässen niedriger Geschwindigkeiten ist in EN 12239 festgelegt.
Ventilation des bâtiments - Bouches d'air - Essais aérodynamiques et caractérisation pour applications en diffusion à mélange
La présente Norme européenne spécifie les méthodes pour les essais aérodynamiques en laboratoire et la caractérisation, des bouches d'air utilisées dans des applications en diffusion à mélange, y compris la spécification de dispositifs d'essai et de techniques de mesure appropriées.
La présente norme ne traite que des essais permettant d'évaluer les caractéristiques des bouches d'air dans des conditions isothermes.
L'essai des bouches d'air à basse vitesse est spécifiée dans l'EN 12239.
Prezračevanje stavb - Naprave za razvod zraka - Aerodinamično preskušanje in ocenitev aplikacij strujanja zraka
General Information
Relations
Standards Content (Sample)
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Lüftung von Gebäuden - Luftdurchlässe - Aerodynamische Prüfung und Bewertung für Anwendung bei MischströmungVentilation des bâtiments - Bouches d'air - Essais aérodynamiques et caractérisation pour applications en diffusion a mélangeVentilation for buildings - Air terminal devices - Aerodynamic testing and rating for mixed flow application91.140.30VLVWHPLVentilation and air-conditioningICS:Ta slovenski standard je istoveten z:EN 12238:2001SIST EN 12238:2001en01-december-2001SIST EN 12238:2001SLOVENSKI
STANDARD
EUROPEAN STANDARDNORME EUROPÉENNEEUROPÄISCHE NORMEN 12238August 2001ICS 91.140.30English versionVentilation for buildings - Air terminal devices - Aerodynamictesting and rating for mixed flow applicationVentilation des bâtiments - Bouches d'air - Essaisaérodynamiques et caractérisation pour applications endiffusion à mélangeLüftung von Gebäuden - Luftdurchlässe - AerodynamischePrüfung und Bewertung für Anwendung bei MischströmungThis European Standard was approved by CEN on 29 June 2001.CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this EuropeanStandard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such nationalstandards may be obtained on application to the Management Centre or to any CEN member.This European Standard exists in three official versions (English, French, German). A version in any other language made by translationunder the responsibility of a CEN member into its own language and notified to the Management Centre has the same status as the officialversions.CEN members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece,Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMITÉ EUROPÉEN DE NORMALISATIONEUROPÄISCHES KOMITEE FÜR NORMUNGManagement Centre: rue de Stassart, 36
B-1050 Brussels© 2001 CENAll rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN 12238:2001 ESIST EN 12238:2001
Alternative exploratory technique for determination of throw, spreadand drop.30A.1Scope.30A.2Determination of the point of maximum velocity.30A.3Determination of points at envelope velocity.31A.4Determination of spread.31A.5Determination of the rise and drop.31A.6Number of determinations.31SIST EN 12238:2001
— Part 1: Orificeplates, nozzles and Venturi tubes inserted in circular cross-section conduits running full[ISO 5167-1: 1991]3 Terms, definitions and symbolsFor the purposes of this standard, the terms and definitions given in CR 12792, together with thefollowing, apply.3.1 functional characteristics of air terminal devicesNOTEThe acroynym ATD is used to signify an air terminal device.3.1.1nominal size of an air terminal devicenominal value of dimensions of the duct into which the air terminal device is to be fittedNOTEFor an air diffuser, the nominal size is generally known as neck size.SIST EN 12238:2001
core and specific areas3.1.2.1core of an air terminal devicethat part of an air terminal device located within a convex closed surface of minimum area, inside whichare all the openings of the air terminal device through which the air can pass3.1.2.2free area (of an air terminal device)sum of the smallest areas of the cross-section of all openings of the air terminal device3.1.2.3core of a grillethat part of a grille located inside a convex closed plane curve of minimum length of contour, inside whichare all the openings of the grille3.1.2.4core area (of a grille)area limited by the plane curve defined in 3.1.2.33.1.2.5free area (of a grille)sum of the minimum measured areas of each opening through which the air can pass3.1.2.6free area ratio (of a grille)ratio of the free area to the core area3.1.2.7effective area of an air terminal device Akquotient resultant from measured air flow rate and measured air velocity as determined in a specifiedmanner with a specified instrument3.1.3 aspect and vane ratios3.1.3.1aspect ratio (of a rectangular air terminal device)ratio of the larger side to the smaller side of the rectangular core3.1.3.2vane ratio (of a grille)ratio of the chord length to the vane pitch3.1.4Special terms relating to air3.1.4.1standard airatmospheric air having a density of 1,2 kgm-3 at 20 C, 101 325 Pa (1 013,25 mbar) and 65 % RelativeHumidity3.1.4.2supply airair entering a supply air terminal device from an upstream duct3.1.4.3induced airairflow induced by the supply air from a supply air terminal deviceSIST EN 12238:2001
in this standard are given in Table 1.Table 1 — SymbolsSymbolQuantitySI unitAAream2AdArea corresponding to the cross section of the nominal sizeof the duct to which the device is fitted (neck area)m2AfFree aream2AkEffective area (k-factor area)
kvvqm2bRWidth of test room or installationmDeEquivalent diameter
dA4mDhHydraulic diameter
perimeterA4dmdDiametermhDFace height of linear grille of diffusermhRHeight of test room or installationmlRLength of test room or installationmpsaAbsolute static pressurePapaAtmospheric pressurePapsStatic pressure or static gauge pressure (psa - pa)PaptaStagnation (or absolute total) pressurePaptTotal pressure (pta - pa)Papt1,2Total pressure corresponding to a density of 1,2 kgm-3PaptDTotal pressure requirement of the devicePaSIST EN 12238:2001
Symbols [concluded]SymbolQuantitySI unitps1,2Static gauge pressure corresponding to a density of1,2 kgm-3PapsDStatic pressure requirement of the devicePapd1,2Dynamic pressure (Velocity pressure)
2v2PapPressure difference (for a pressure difference device)PaqvVolume rate of flowm3s-1vVelocityms-1Velocity referred to the effective area (k-factor velocity)vk
Aqkvms-1vxMaximum velocity at distance x from centre of supply airterminal devicems-1xDistance from supply air terminal device along the centrelineof the jetmXThrowmYSpreadmZDropmLoss coefficient-Thermodynamic temperatureKDensity of airkgm-3RArea parameter that relates to the effective size of the airterminal devicem2SLinear parameter that relates to the effective size of the airterminal devicemXCCoordinate (see annex A)mYCCoordinate (see annex A)mZCCoordinate (see annex A)mSIST EN 12238:2001
7±
2,5> 0,007
0,07± 5,0NOTEFlow meters can be calibrated in situ by means of the Pitot static tube traverse techniques described inISO 3966.4.1.3Flow meters shall be checked at intervals as appropriate but not exceeding 12 months. Thischeck may take the form of one of the following:a) a dimensional check for all flow meters not requiring calibration;b) a check calibration over their full range using the original method employed for the initialcalibration of meters calibrated in situ;c) a check against a flow meter which meets EN ISO 5167-1.4.2 Pressure measurement4.2.1Pressure in the duct shall be measured with a calibrated manometer.4.2.2The maximum scale interval shall not be greater than the characteristics listed for theaccompanying range of manometer, shown in Table 3.Table 3 — Maximum scale intervals for the ranges of manometersRangeMaximum scale intervalPaPa
251,0> 25
2502,5> 250
5005,0> 50025SIST EN 12238:2001
may bycalculated from the following appropriate relationships, based upon the pressures measured under5.1.2, 5.1.3 and 5.1.4.5.1.4) and 5.1.3 (see
pp = dt5.1.2)(see
1 + pp = dsWhere pt and ps are the measured quantities and pd is calculated as follows:dvdAqp2and where both
and qv are at the same test conditions.5.2 Measurement of pressure requirement for an exhaust air terminal device5.2.1 Procedure5.2.1.1 The pressure requirement of an exhaust air terminal device is for a given value of flow ratedependent on the type and size of the device and on the velocity profile upstream and downstream ofthe device. A standard test duct immediately downstream of the air terminal device shall be employed.If a connecting duct arra
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.
Loading comments...