1、BRITISH STANDARD Ventilation for buildings - Air terminal devices - Aerodynamic testing and rating for mixed flow application The European Standard EN 12238:2001 has the status of a British Standard ICs 91.140.30 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW BS EN 12238:2001
2、 BS EN 12238:2001 Amd. No. National foreword Date Comments This British Standard. having been prepared under the direction of the Engineering Sector Policy and Strategy Committee, was published under the authority of the Standards Policy and Strategy Committee on 16 October 2001 This British Standar
3、d is the official English language version of EN 12238:2001. The UK participation in its preparation was entrusted to Technical Committee RHE/2, Air distribution and air diffusion, which has the responsibility to: - - aid enquirers to understand the text; present to the responsible European committe
4、e any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; monitor related international and European developments and promulgate them in the UK. - A list of organizations represented on this committee can be obtained on request to its secretary. Cross-refere
5、nces The British Standards which implement international or European publications referred to in this document may be found in the BSI Standards Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Find” facility of the BSI Standards Electronic Catalo
6、gue. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itselfconfer immunity from legal obligations. Summary of pages This document compri
7、ses a front cover, an inside front cover, the EN title page, pages 2 to 33 and a back cover. The BSI copyright date displayed in this document indicates when the document was last issued. Amendments issued since publication 0 BSI 16 October 2001 ISBN O 580 38234 6 EUROPEAN STANDARD NORME EUROPENNE E
8、UROPISCHE NORM EN 12238 August 2001 ICs 91.140.30 English version Ventilation for buildings - Air terminal devices - Aerodynamic testing and rating for mixed flow application Ventilation des btiments - Bouches dair - Essais arodynamiques et caractrisation pour applications en diffusion mlange LLiftu
9、ng von Gebauden - Luftdurchlasse - Aerodynamische PrOfung und Bewertung for Anwendung bei MischstrOmung Thls European Standard was approved by CEN on 29 June 2001. CEN members are bound to comply with the CENICENELEC Internal Regulations which stipulate the conditions for giving this European Standa
10、rd the status of a national standard without any alteration. Up-to-date lists and biblicgraphical references concerning such national standards may be obtained on application to the Management Centre or to any CEN member. This European Standard exists in three official versions (English, French, Ger
11、man). A version in any other language made by translation under the responsibility of a CEN member into its own language and notiied to the Management Centre has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium. Czech Republic. Denmark, Finl
12、and, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION EUROPISCHES KOMITEE FUR NORMUNG COMIT EUROPEN DE NORMALISATION Management Centre: rue de Stassart, 36 8-1050 Brussel
13、s O 2001 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 12238:2001 E EN 12238:2001 (E) Contents Page Foreword . 3 I 2 3 3.1 3.2 4 4.1 4.2 4.3 4.4 5 5.1 5.1.1 5.1.2 5.1.3 5.1.4 5.1.5 5.2 5.2.1 5.2.2 5.2.3 5.2.4 5.2.5 5.3 5.3.1 5.3.
14、2 5.3.3 5.3.4 5.3.5 6 6.1 6.2 6.3 6.4 6.4.1 6.4.2 6.4.3 6.5 6.6 6.6.1 6.6.2 6.6.3 6.6.4 6.6.5 6.6.6 Scope . 4 Normative references . 4 Terms, definitions and symbols 4 Functional characteristics of air terminal devices . 4 Symbols 8 Instrumentation . 10 Aifflow rate measurement . 10 Pressure measure
15、ment . 10 Temperature measurements . 11 Velocity measurements . 11 Testing of pressure and air velocity vk (first test installation) 11 Measurement of pressure requirement for a supply air terminal device . 11 General . 11 Measurement of static gauge pressure ps with the first test installation A 12
16、 Direct measurement of total pressure p, with the first test installation A . 12 Measurement of static pressure pr with the first test installation B . 13 Presentation of total pressure p , 13 Measurement of pressure requirement for an exhaust air terminal device 14 Procedure 14 Measurement of stati
17、c pressure with the first test installation C for exhaust air terminal device (excluding air transfer devices) . 15 Direct measurement of total pressure with the first test installation C, for exhaust air terminal device . 15 Measurement of static pressure with the first test installation D for exha
18、ust air terminal device . 16 Presentation of total pressure p, 16 Determination of air velocity vk and the corresponding area At for the air terminal device (not mandatory) . 17 Principle 17 Test installation . 17 Test procedure 17 Correction of flow rates to standard air conditions 18 Calculation o
19、f Ak 18 Test to measure the isothermal air discharge characteristics of a supply air terminal device (second test installation) 18 Test measurements 18 Test room 18 Test room equipment and instrumentation . 19 Installation of the air terminal device . 19 Classification of air terminal devices . 19 M
20、ounting of air terminal devices . 19 Test duct and flow rate 19 Test procedure 20 Determination of isothermal performance . 20 Test measurements 20 Determination of the main air stream direction . 20 Measurement of air stream velocities . 21 Determination of throw 21 Determination of spread 22 Deter
21、mination of rise and drop 22 Annex A (normative) Alternative exploratory technique for determination of throw. spread and drop . 28 A.l Scope 28 A.2 Determination of the point of maximum velocity . 28 A.3 Determination of points at envelope velocity 29 A.4 Determination of spread 29 A.5 Determinatio
22、n of the rise and drop 29 A.6 Number of determinations . 29 2 Foreword This European Standard has been prepared by Technical Committee CENTTC 156, Ventilation for buildings, the Secretariat of which is held by BSI. This European Standard shall be given the status of a national standard, either by pu
23、blication of an identical text or by endorsement, at the latest by February 2002, and conflicting national standards shall be withdrawn at the latest by February 2002. According to the CENICENELEC Internal Regulations, the national standards organizations of the following countries are bound to impl
24、ement this European Standard: Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom. 3 EN 12238:2001 (E) 1 Scope This European Standard specifies methods for t
25、he 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 condi
26、tions. The testing of low velocity air terminal devices is specified in EN 12239. 2 Normative references This European Standard incorporates by dated or undated reference, provisions from other publications. These nonnative references are cited at the appropriate places in the text and the publicati
27、ons are listed hereafter. For dated references the subsequent amendments to or revisions of any of these publications apply to this European Standard only when incorporated in it by amendment or revision. For undated references the latest edition of the publication referred to applies (including ame
28、ndments). CR 12792, Ventilation for buildings - Symbols and terminology. EN 12239, Ventilation for buildings - Air terminal devices - Aerodynamic testing and rating for displacement flow applications. prEN 131 82: 1998, Ventilation for buildings - Instrumentation requirements for air veIoc measureme
29、nts in ventilated spaces. IS0 3966, Measurement of fluid flow in closed conduits - Velocity area method using Pitot static tubes. EN IS0 5167-1, Measurement of fluid flow by means of pressure differential devices - Part I: Orifice plates, nozzles and Venturi tubes inserfed in circular cross-section
30、conduits running full (IS0 5167-1:1991). 3 Terms, definitions and symbols For the purposes of this standard, the terms and definitions given in CR 12792, together with the following, apply. 3.1 Functional characteristics of air terminal devices NOTE The acroynym ATD is used to signify an air termina
31、l device. 3.1.1 nominal size of an air terminal device nominal value of dimensions of the duct into which the air terminal device is to be fitted NOTE For an air diffuser, the nominal size is generally known as neck size. 3.1.2 core and specific areas 3.1.2.1 core of an air terminal device that part
32、 of an air terminal device located within a convex closed surface of minimum area, inside which are all the openings of the air terminal device through which the air can pass 4 EN 12238:2001 (E) 3.1.2.2 free area (of an air terminal device) sum of the smallest areas of the cross-section of all openi
33、ngs of the air teminal device 3.1.2.3 core of a grille that part of a grille located inside a convex closed plane curve of minimum length of contour, inside which are all the openings of the grille 3.1.2.4 core area (of a grille) area limited by the plane curve defined in 3.1.2.3 3.1.2.5 free area (
34、of a grille) sum of the minimum measured areas of each opening through which the air can pass 3.1.2.6 free area ratio (of a grille) ratio of the free area to the core area 3.1.2.7 effective area of an air terminal device Ak quotient resultant from measured airflow rate and measured air velocity as d
35、etermined in a specified manner with a specified instrument 3.1.3 aspect and vane ratios 3.1.3.1 aspect ratio (of a rectangular air terminal device) ratio of the larger side to the smaller side of the rectangular core 3.1.3.2 vane ratio (of a grille) ratio of the chord length to the vane pitch 3.1.4
36、 special terms relating to air 3.1.4.1 standard air atmospheric air having a density of 1,2 kg.m-3 at 20 OC, 101 325 Pa (1 013,25 mbar) and 65 % Relative Humidity 3.1.4.2 supply air air entering a supply air terminal device from an upstream duct 3.1.4.3 induced air airflow induced by the supply air
37、from a supply air terminal device 3.1.4.4 exhaust air air leaving an exhaust air terminal device into a downstream duct 3.1.5 specific terms relating to air diffusion rating 3.1.5.1 mean measured air temperature of the occupied zone arithmetical average of the measured values of air temperature with
38、in the occupied zone 5 EN 12238:2001 (E) 3.1 5.2 supply temperature differential algebraic difference between the supply air temperature and the mean measured air temperature of the occupied zone 3.1.5.3 exhaust temperature differential algebraic difference of the exhaust air temperature and the mea
39、n measured air temperature of the occupied zone 3.1.5.4 temperature differential within the occupied zone largest value of the difference between measured air temperatures within the occupied zone 3.1.5.5 primary airflow rate volume of air entering a supply air terminal device in unit time from an u
40、pstream duct 3.1.5.6 exhaust airflow rate volume of air leaving an exhaust air terminal device in unit time 3.1.5.7 local air velocity magnitude of the time-averaged vector of velocity at a point of an air stream The velocity vector (and therefore its three mutually perpendicular components u, v, w)
41、 in any point of a turbulent stream is submitted to fluctuations with respect to time. The time-averaged vector of velocity is a vector for which each component is averaged with respect to time. The components being: the local air velocity is therefore: 4; +i2 +w2 3.1.5.8 local measured air velocity
42、 measured value of local air velocity 3.1.5.9 treated space enclosure served by an air distribution system NOTE In this standard the treated space is the test room described in 6.2. 3.1.5.10 envelope geometrical surface in a treated space where the local measured air velocity has the same value and
43、is the reference velocity associated with this envelope 3.1.5.1 1 room air velocity value of velocity conventionally derived from the various local measured air velocities within the occupied zone 3.1.5.12 free area velocity primary airflow rate divided by the free area of a supply air terminal devi
44、ce or exhaust airflow divided by the free area of an exhaust air terminal device 6 EN 12238:2001 (E) 3.1.5.13 throw (for a supply air terminal device) maximum distance between the centre of the core and a plane which is tangent to a specified envelope, such as 0.25 ms-, 0,5 rns-, etc., and the centr
45、e of the core 3.1.5.14 drop (for a supply air terminal device) vertical distance between the lowest horizontal plane tangent to a specified envelope, such as 0,25 mS, 0,5 ms-, etc., and the centre of the core 3.1.5.15 rise (for a supply air terminal device) vertical distance between the highest hori
46、zontal plane tangent to a specified envelope, such as 0,25 m.s-, 0,5 ms-, etc., and the centre of the core 3.1.5.16 spread (for a supply air terminal device) maximum distance between two vertical planes tangent to a specified envelope, such as 0,25 m.s-, 0,5 m.s-, etc., and perpendicular to a plane
47、through the centre of the core There can be two different spreads, which are not always equal: one for the left side, the other for the right side (considered when looking at the treated space from the supply air teminal device). 3.1.5.17 occupied zone (for laboratory purposes) portion of the treate
48、d space geometrically limited to be no closer than 0,15 m to all walls and within a height of 1,8 m above the floor 3.1.5.18 slot air terminal device device with single or multiple components with aspect ratio (the ratio of length to width of the enclosed rectangular opening) of 1O:l or greater for
49、each slot 7 EN 12238:2001 (E) 3.2 Symbols The symbols used in this standard are given in Table 1. Table 1 - Symbols Symbol A Ad Af Ak hR D, Dh d hD hR IR Psa Pa PI; Pia Pi Ptl.2 Pi0 Quantitv Area Area corresponding to the cross section of the nominal size of the duct to which the device is fitted (neck area) Free area (?I Effective area (k-factor area) Width of test room or installation I?) Equivalent diameter ( perimeter 4xAd 1 Hydraulic diameter Diameter Face height of linear grille of diffuser Height of test room or installation Length of test room or installation Abs
