AS 4254 1995 ductwork for air handling systems in buildings

Title AS 4254-1995 Ductwork for air-handling systems in buildings Licensee Licensed to LUU MINH LUAN on 26 Feb 2002 Conditions of use This is a licensed electronic copy of a document where copyright is owned or managed by Standards Australia International Your licence is a single user licence and the document may not be stored, transferred or otherwise distributed on a network You may also make one paper copy of this document if required Web Check-up Licensed to LUU MINH LUAN on 26 Feb 2002 Single user licence only Storage, distribution or use on network prohibited AS 4254—1995 Australian Standard  Ductwork for air-handling systems in buildings This Australian Standard was prepared by Committee ME/62, Mechanical Ventilation and Air Conditioning It was approved on behalf of the Council of Standards Australia on 21 September 1994 and published on January 1995 The following interests are represented on Committee ME/62: Association of Consulting Engineers Australia Australian Assembly of Fire Authorities Australian Construction Services Australian Institute of Refrigeration Air Conditioning and Heating Australian Uniform Building Regulations Coordinating Council Building Owners and Managers Association of Australia Licensed to LUU MINH LUAN on 26 Feb 2002 Single user licence only Storage, distribution or use on network prohibited Council of Air Conditioning and Mechanical Contractors Associations of Australia Department of Health, New South Wales Fire Protection Industry Associations of Australia Insurance Council of Australia Metal Trades Industry Association of Australia State Projects, New South Wales Additional interests participating in preparation of Standard: Council of the City of Sydney Review of Australian Standards To keep abreast of progress in industry, Australian Standards are subject to periodic review and are kept up to date by the issue of amendments or new editions as necessary It is important therefore that Standards users ensure that they are in possession of the latest ed ition, and any amendments thereto Full details of all Australian Standards and related publications will be found in the Standards Australia Catalogue of Publications; this information is supplemented each month by the magazine ‘The Australian Standard’, which subscribing members receive, and which gives details of new publications, new editions and amendments, and of withdrawn Standards Suggestions for improvements to Australian Standards, addressed to the head office of Standards Australia, are welcomed Notification of any inaccuracy or ambiguity found in an Australian Standard should be made without delay in order that the matter may be investigated and appropriate action taken This Standard was issued in draft form for comment as DR 93109 AS 4254—1995 Licensed to LUU MINH LUAN on 26 Feb 2002 Single user licence only Storage, distribution or use on network prohibited Australian Standard ® Ductwork for air-handling systems in buildings First published as AS 4254 — 1995 Incorporating: Amdt 1—1996 Amdt 2—1999 PUBLISHED BY STANDARDS AUSTRALIA (STANDARDS ASSOCIATION OF AUSTRALIA) THE CRESCENT, HOMEBUSH, NSW 2140 ISBN 7262 9341 AS 4254 — 1995 PREFACE This Standard was prepared by the Joint Standards Australia/Standards New Zealand Committee ME/62 on Mechanical Ventilation and Air Conditioning In the preparation of this Standard, consideration was given to a number of publications and relevant Standards This Standard follows a number of requirements set out in the Sheet Metal and Air Conditioning Contractors National Association’s (SMACNA) HVAC Duct Construction Standards for metal and flexible ducts, but with the requirements adapted to the products of local Australian industries The objective of this Standard is to provide guidance to designers, manufacturers and installers of air-handling systems for buildings The approach to using SMACNA as the basis for an Australian Standard was strongly influenced by — (a) the extensive long-term background of SMACNA, which led this document to be regarded as well developed; and (b) the use of SMACNA in Australia over a considerable period as the basis for duct construction Licensed to LUU MINH LUAN on 26 Feb 2002 Single user licence only Storage, distribution or use on network prohibited Assistance gained from SMACNA is hereby acknowledged The terms ‘normative’ and ‘informative’ have been used in this Standard to define the application of the appendix to which they apply A ‘normative’ appendix is an integral part of a Standard, whereas an ‘informative’ appendix is only for information and guidance Statements expressed in mandatory terms in notes to tables and figures are deemed to be requirements of this Standard  Copyright STANDARDS AUSTRALIA Users of Standards are reminded that copyright subsists in all Standards Australia publications and software Except where the Copyright Act allows and except where provided for below no publications or software produced by Standards Australia may be reproduced, stored in a retrieval system in any form or transmitted by any means without prior permission in writing from Standards Australia Permission may be conditional on an appropriate royalty payment Requests for permission and information on commercial software royalties should be directed to the head office of Standards Australia Standards Australia will permit up to 10 percent of the technical content pages of a Standard to be copied for use exclusively in-house by purchasers of the Standard without payment of a royalty or advice to Standards Australia Standards Australia will also permit the inclusion of its copyright material in computer software programs for no royalty payment provided such programs are used exclusively in-house by the creators of the programs Care should be taken to ensure that material used is from the current edition of the Standard and that it is updated whenever the Standard is amended or revised The number and date of the Standard should therefore be clearly identified The use of material in print form or in computer software programs to be used commercially, with or without payment, or in commercial contracts is subject to the payment of a royalty This policy may be varied by Standards Australia at any time AS 4254 — 1995 CONTENTS Licensed to LUU MINH LUAN on 26 Feb 2002 Single user licence only Storage, distribution or use on network prohibited Page SECTION SCOPE AND GENERAL 1.1 SCOPE 1.2 NEW DESIGNS AND INNOVATIONS 1.3 APPLICATION 1.4 REFERENCED DOCUMENTS 1.5 DEFINITIONS 1.6 GENERAL REQUIREMENTS 1.7 STATIC PRESSURE CLASSIFICATION 1.8 GALVANIZED STEEL THICKNESS 1.9 TESTING SECTION DUCT CONSTRUCTION AND INSTALLATION 2.1 DUCT WORK 2.2 DUCT SEALING 2.3 RECTANGULAR DUCT REINFORCEMENT 2.4 ROUND DUCT CONSTRUCTION 2.5 OVAL DUCT CONSTRUCTION 2.6 HANGERS AND SUPPORT SYSTEMS 2.7 DUCT LINERS AND INSULATION 2.8 FLEXIBLE DUCTWORK SECTION EXTERNAL EQUIPMENT INSTALLATION 3.1 GENERAL 3.2 ROOF PENETRATIONS 3.3 CONNECTION TO EQUIPMENT 3.4 SEALING OF EXTERNAL DUCTWORK 4 4 7 8 9 12 46 54 56 64 66 71 71 71 71 SECTION FUNCTIONAL CRITERIA 4.1 DEFLECTION 76 4.2 MODELS FOR FUNCTIONAL STANDARDS 76 APPENDICES A PROCEDURE FOR RATING DUCT CONSTRUCTION METHODS RELATIVE TO THE CONSTRUCTION TABLES B ‘J’ AND ‘I’ REINFORCEMENT RELATED TO ‘EI’ VALUES C ALLOWABLE LOADS FOR TRAPEZE ANGLES D CIRCULAR EQUIVALENT OF RECTANGULAR DUCTS E WEIGHTS AND AREAS OF RECTANGULAR GALVANIZED STEEL DUCTS F WEIGHTS AND AREAS OF CIRCULAR GALVANIZED STEEL DUCTS 78 80 81 83 84 85 AS 4254 — 1995 STANDARDS AUSTRALIA Australian Standard Ductwork for air-handling systems in buildings S E C T I O N S C O P E A N D G E N E R A L 1.1 SCOPE This Standard specifies the performance, materials, construction and installation of ductwork for air-handling systems in buildings 1.2 NEW DESIGNS AND INNOVATIONS Any alternative materials, designs, methods of assembly, and procedures that not comply with specific requirements of this Standard, or are not mentioned in it, but give equivalent results to those specified, are not necessarily prohibited (See Appendix A) Licensed to LUU MINH LUAN on 26 Feb 2002 Single user licence only Storage, distribution or use on network prohibited 1.3 APPLICATION This Standard applies to ductwork for air-handling systems designed in accordance with the requirements of AS 1668.1 and AS 1668.2 1.4 REFERENCED DOCUMENTS Standard: The following documents are referred to in this AS 1397 Steel sheet and strip — Hot-dipped zinc-coated or aluminium/zinc coated 1449 Wrought alloy steels—Stainless and heat-resisting steel plate, sheet and strip 1530 1530.1 1530.2 1530.3 1530.4 Methods for fire tests on building materials, components and structures Part 1: Combustibility test for materials Part 2: Test for flammability of materials Part 3: Simultaneous determination of ignitability, flame propagation, heat release and smoke release Fire-resistance tests of elements of building construction 1599 Pressure sensitive adhesive packaging tapes 1668 1668.1 1668.2 The use of mechanical ventilation and air conditioning in buildings Part 1: Fire and smoke control Part 2: Mechanical ventilation for acceptable indoor-air quality 1682 1682.2 Fire dampers Part 2: Installation 1734 Aluminium and aluminium alloys—Flat sheet, coiled sheet and plate 1866 Aluminium and aluminium alloys—Extruded rod, bar, solid and hollow shapes 1903 Reflective foil laminate 2338 Preferred dimensions of wrought metal products 3666 Air handling and water systems of buildings — Microbial control 3679 3679.1 Structural steel Part 1: Hot-rolled bars and sections UL 181 Factory made air ducts and air connectors COPYRIGHT 1.5 DEFINITIONS AS 4254 — 1995 For the purpose of this Standard, the definitions below apply 1.5.1 Airflow rate (herein referred to as ‘flow rate’) — the volumetric flow rate derived from the mass flow rate by dividing it by the density, assumed to be 1.2 kg/m (1.2 g/L) 1.5.2 Air-handling plant— a component part of an air-handling system that includes equipment providing air movement, as well as equipment for the purpose of controlling the direction, rate of airflow, division of airflow and condition of air, i.e concentration level of contaminants, temperature and humidity 1.5.3 Air-handling system — a system for the purpose of directing air in a controlled manner to or from specific enclosures by means of air-handling plant, ducts, plenums, airdistribution devices and automatic controls 1.5.4 Air-pressurization system — an air-handling system which establishes a pressure differential to provide a flow of air from a fire-isolated escape route into normally occupied spaces 1.5.5 Air outlet — any opening through which air is delivered to an enclosure by an airhandling system of a building Licensed to LUU MINH LUAN on 26 Feb 2002 Single user licence only Storage, distribution or use on network prohibited 1.5.6 Approved and approval— approved by, or the approval of, the regulatory authority concerned 1.5.7 Combustible— deemed combustible when tested in accordance with AS 1530.1 1.5.8 Compartment — a fire compartment as defined in the Building Code of Australia 1.5.9 Downstream — in the direction of airflow 1.5.10 Duct — a component part of an air-handling system, intended for the passage of air from one part of an air-handling system to another (See also definition of ‘plenum’) 1.5.11 Duct liner — internal lining of duct usually provided for thermal or acoustic insulation, or both, including the facing material thereon 1.5.12 Exhaust air — air, other than return air, removed from an enclosure by mechanical means and discharged to atmosphere 1.5.13 Exhaust air intake — any opening through which air is extracted from an enclosure by an air-handling system of a building 1.5.14 Exhaust outlet — an outlet from an air-handling system, discharging to atmosphere 1.5.15 Facing material — thin flexible material (e.g reflective foil laminate) used for the facing of duct liner or insulation or for the manufacture of flexible duct 1.5.16 Fail-safe— the position the device reverts to upon loss of operating power as applicable 1.5.17 Fire alarm — a device which may be operated manually or automatically and which is intended to provide warning of the existence of a fire 1.5.18 Fire damper — a complete assembly complying with AS 1682.2 1.5.19 Fire-isolated — separated by fire-resistant construction 1.5.20 Fire resistance level (FRL) — the grading periods in minutes determined in accordance with AS 1530.4 for— (a) structural adequacy; (b) integrity; and (c) insulation, expressed in that order COPYRIGHT AS 4254 — 1995 1.5.21 Fire-resisting — describes an element of construction, component or structure which, by requirement of the regulatory authority, has a specified FRL 1.5.22 Flexible connection — a section of flexible material used at junctions between ductwork and items of plant that are subject to vibration 1.5.23 Flexible duct — a factory-made, preformed duct that can be bent or compressed by hand 1.5.24 Hood— a component part of a local exhaust system intended for collecting effluents 1.5.25 Infiltration air — air, other than supply air and make-up air, that enters an enclosure or an air-handling system in an uncontrolled manner 1.5.26 Insulated flexible duct — flexible duct wrapped in a blanket of thermal insulating material 1.5.27 Insulation— external lining of rigid or flexible duct usually provided for thermal or acoustic insulation, or both, including any facing material thereon 1.5.28 Jacket/sleeve — an air and vapour tight enclosure around the insulating blanket applied to insulated flexible duct Licensed to LUU MINH LUAN on 26 Feb 2002 Single user licence only Storage, distribution or use on network prohibited 1.5.29 seam Joint — any surface connection made on the perimeter of a duct, other than a 1.5.30 Leakage air — air, other than exhaust air, return air and relief air, that escapes from an air-handling system in an uncontrolled manner 1.5.31 May — indicates the existence of an option 1.5.32 Objectionable effluent —a ny unwanted airborne constituents that may reduce the acceptability of air 1.5.33 Outdoor air — air outside the building 1.5.34 Outdoor air intake — any opening through which outdoor air is admitted to an air-handling system of a building 1.5.35 Plant room — a room which contains items of plant or machinery 1.5.36 Plenum — an air compartment or chamber, intended for the passage of air, to which one or more ducts may be connected and which forms part of an air-handling system 1.5.37 Recycled air — that portion of indoor air removed from enclosures as return air and returned as part of the supply air, by mechanical means 1.5.38 Regulatory authority — an authority having statutory powers to control design, construction, installation, operation or testing of air-handling systems in buildings 1.5.39 Relief air — air that flows from an enclosure in a controlled manner by other than mechanical means 1.5.40 Required — required by any government act, regulation, by-law or statutory rule, or by any regulatory authority NOTE: Fire insurance underwriters and other bodies may have requirements in excess of those required by regulatory authorities 1.5.41 Return air — air removed from an enclosure by mechanical means All of the return air may be expelled as spill air, or all or part of it may be recycled 1.5.42 Seam — any surface connection joining two longitudinally-oriented edges of duct surface material occurring between two joints 1.5.43 Shall— indicates that a statement is mandatory COPYRIGHT 1.5.44 Should— indicates a recommendation 1.5.45 Spill air — that portion of return air that is not recycled 1.5.46 Supply air — air introduced into an enclosure by mechanical means 1.5.47 Upstream — against the direction of airflow AS 4254 — 1995 1.6 GENERAL REQUIREMENTS A duct system is a structural assembly, the primary function of which is to convey air between specific points To fulfil this function, the duct assembly must perform satisfactorily with regard to certain fundamental performance characteristics Licensed to LUU MINH LUAN on 26 Feb 2002 Single user licence only Storage, distribution or use on network prohibited Elements of the assembly are sheets (duct envelope), reinforcement, seams and joints With regard to the duct assembly and its elements, theoretical or practical limits must be established for: (a) Dimensional stability (deformation and deflection) under positive or negative pressure applications or static loads (b) Leakage under positive or negative pressure (c) Vibration (d) Support (including any supplemental loads) The following Items (e) to (i) are not covered in detail in this Standard, but are included for information: (e) Noise generation and transmission (f) Exposure to damage from— (g) (i) transportation and handling; (ii) weather and temperature extremes; (iii) flexure cycle; (iv) chemical corrosion; and (v) other in-service conditions specific to the installation Impact loading such as — (i) fire; (ii) earthquake; or (iii) sudden stoppage of airflow (h) Cleanability (i) Resistance to airflow In establishing limitations for these factors, consideration must be given to the effects of pressure differential across the ductwork, airflow friction losses, air velocity, infiltration or exfiltration, as well as the inherent strength characteristics of the duct components Construction methods that will permit an economic attainment of the predicted and desired performance must be determined 1.7 STATIC PRESSURE CLASSIFICATION The pressure classification number denotes construction suitable for a maximum level not less than the maximum operating pressure in the portion of the system receiving classification from the designer The pressure classifications are as follows: COPYRIGHT 71 S E C T I O N AS 4254—1995 E X T E R N A L E Q U I P M E N T I N S T A L L A T I O N 3.1 GENERAL Each installation of external ductwork systems involves customized design requirements, therefore the construction details and recommendations herein are advisory and are dependent on design documents for clarification of obligations Openings in roofs require coordination of architectural, structural, mechanical and electrical elements The elevation of equipment and ducts may be influenced by wind loading as well as aesthetic considerations Designers shall specify construction appropriate for the specific locality and circumstances Licensed to LUU MINH LUAN on 26 Feb 2002 Single user licence only Storage, distribution or use on network prohibited 3.2 ROOF PENETRATIONS Roof penetrations by ducts shall have curbs Ducts that are interrupted at the curb shall overhang the top of the curb or be flashed to divert water over the curb Ducts that are continuous through the curb shall have flashing that slopes over the curb and is sealed to the duct with caulking or a suitable tape Adequate clearances between ducts and roof penetration openings shall be provided See Figure 3.1 Curbs may be supplied with the proprietary units or provided independently The equipment manufacturer may outline flashing methods, structural opening requirements, sealing techniques, etc., which shall be coordinated with project construction With considerable pitch in the roof level a sub-base may be required to adapt to a preengineered curb Furthermore, curb mountings may incorporate vibration isolation features Supports for ducts shall be as indicated in Figure 3.2 If the support does not rest on a cap flashed curb, the penetration of the roof membrane shall be under-flashing and overflashing 3.3 CONNECTION TO EQUIPMENT Unless otherwise prescribed by the equipment manufacturer, ducts shall be flanged for attachment to equipment with mechanical fastening supplemented with exterior duct sealant Typical connections are shown in Figure 3.3 The attachment method shall accommodate disconnection if this is required for routine maintenance of the equipment Where vibration isolation material is required at the connection of ducts to equipment, such material should be impervious to water Ducts shall be supported to avoid transfer of duct weight across flexible connections 3.4 SEALING OF EXTERNAL DUCTWORK All ducts that are not inherently watertight through the use of welded constructions or protective shields and are exposed directly to weather and solar radiation shall have secure watertight mechanical connections and receive exterior duct sealant treatment as defined in ‘duct sealing requirements’ Exterior duct sealant treatment shall consist of the supplemental application of a product or products marketed specifically as forming a positive airtight and watertight seal, bonding well to the metal involved, remaining watertight with metal movement and having a suitable service temperature range (−10°C to 78°C) If exposed to direct sunlight it shall also be ultraviolet ray and ozone resistant or shall, after curing, be painted with a compatible coating which provides that resistance, plus weather resistance The term sealant herein is not limited to materials of adhesive or mastic nature but is inclusive of tapes and combinations of woven fabric strips and mastics Asphalt-based compounds shall not be used for sealing ducts COPYRIGHT AS 4254—1995 72 Licensed to LUU MINH LUAN on 26 Feb 2002 Single user licence only Storage, distribution or use on network prohibited Duct systems should not be pressurized without sufficient time being allowed for curing sealant systems The sealant manufacturer’s recommendations on curing should be followed COPYRIGHT Licensed to LUU MINH LUAN on 26 Feb 2002 Single user licence only Storage, distribution or use on network prohibited 73 AS 4254—1995 NOTES: Duct may be bolted to, or from, roof structure as appropriate, giving consideration to roof and duct movement Metal flashing should extend 75 mm below top of curb Penetration support frame can be situated below or above roof DIMENSIONS IN MILLIMETRES FIGURE 3.1 RECTANGULAR GOOSENECK INTAKE AND PENETRATION COPYRIGHT Licensed to LUU MINH LUAN on 26 Feb 2002 Single user licence only Storage, distribution or use on network prohibited AS 4254—1995 74 Width of equipment Height, H * Up to 600 350 601 to 900 450 901 to 200 600 201 to 500 750 501 and wider 200 * H = clearance for roof maintenance recommended for equipment and ducts NOTE: Flashing requirements are as follows: Height: 200 mm above roof Flange: 75 mm to 100 mm width Clearance to pipe: 6.0 mm Clearance to over flashing: 6.0 mm All are set in mastic and stripped in Flange is fastened to wood nailer on insulated decks Bottom of over flashing to be 100 mm below top of flashing DIMENSIONS IN MILLIMETRES FIGURE 3.2 TYPICAL DUCT SUPPORT FLASHING COPYRIGHT Licensed to LUU MINH LUAN on 26 Feb 2002 Single user licence only Storage, distribution or use on network prohibited 75 NOTES: Rectangular duct is shown but the recommendations apply to any shape and orientation Flange, waterproof and mechanically fasten duct to HVAC unit FIGURE 3.3 DUCT INSTALLATION COPYRIGHT AS 4254—1995 AS 4254—1995 76 S E C T I O N 4.1 F U N C T I O N A L C R I T E R I A DEFLECTION 4.1.1 Sheet below Licensed to LUU MINH LUAN on 26 Feb 2002 Single user licence only Storage, distribution or use on network prohibited The deflection of sheet sections of ducting shall not exceed that shown 4.1.2 Reinforcing pressure Duct dimension Deflection (maximum) mm mm Up to 300 301 to 450 451 to 600 over 600 10.0 12.0 15.0 20.0 Maximum deflection shall be 6.0 mm at maximum operating 4.1.3 Seams Longitudinal seams shall not deform or fail at 150% of maximum operating pressure 4.1.4 Joints Transverse joints shall not fail at 150% of maximum operating pressure Where transverse joints act as reinforcing members, deflection shall be 6.0 mm at maximum operating pressure 4.1.5 Beam strength of duct section A duct section between adjacent hangers shall be capable of carrying its own weight and resist external loads for which it is constructed NOTE: The joints, sheets and support systems included in the construction tables make no allowance for extraneous loads 4.2 MODELS FOR FUNCTIONAL STANDARDS COPYRIGHT See Figure 4.2 Licensed to LUU MINH LUAN on 26 Feb 2002 Single user licence only Storage, distribution or use on network prohibited 77 DIMENSIONS IN MILLIMETRES FIGURE 4.2 MODELS FOR FUNCTIONAL STANDARDS COPYRIGHT AS 4254—1995 AS 4254—1995 78 APPENDIX A PROCEDURE FOR RATING DUCT CONSTRUCTION METHODS RELATIVE TO THE CONSTRUCTION TABLES (Normative) A1 PROCEDURES Any of the following methods may be used to show that alternative material and construction methods comply with the requirements imposed by the functional criteria: Licensed to LUU MINH LUAN on 26 Feb 2002 Single user licence only Storage, distribution or use on network prohibited (a) Written analysis and commentary Show by written analysis and commentary that the features that are different will not result in — (i) a system that satisfies the general requirements to a lesser extent than the system it is proposed to be used in lieu of; or (ii) non-compliance with the functional standards shown (b) Evidence of historical acceptability Show by authenticated records that the alternative system has been in use under the same subjective pressures, velocity levels and other conditions for which acceptance is required (c) Alternative component testing Fabricate and test the alternative component and any contingently related components in a manner that will simulate actual loading and will correlate with performance on the duct, and show that this approach will not impair or reduce the performance of the entire assemblage (d) Alternative system testing Fabricate a specimen using the alternative materials or construction Conduct positive and negative pressure tests as required to conform with requirements Record test proceedings and results obtained using test procedures and instruments that will ensure laboratory standard accuracy Write conclusions showing equivalency with the construction tables Include a diagram of the specimen tested NOTES: Deflection limits are to be measured at the rated pressure class The freedom from structural failure limit is at 150% of rated pressure Results from testing of one specimen only are insufficient to provide adequate data for acceptance COPYRIGHT 79 A2 A2.1 AS 4254—1995 DEPENDENT VARIABLES Relationships The relationships among dependent variables are as follows: (a) For each pressure level and a constant duct size, the thicker the sheet the more distant the reinforcement spacing; the thinner the sheet the closer the reinforcement spacing (b) For a given sheet thickness and constant duct size, reinforcement size and reinforcement spacing reduce with pressure reduction and increase with pressure increase (c) The larger the duct at a given pressure, the larger the reinforcement and the closer the reinforcement spacing on a selected gauge (d) For each combination of sheet thickness, pressure and duct width, a maximum reinforcement spacing occurs beyond which sheet deflection is not controlled by reinforcement size or reinforcement position Licensed to LUU MINH LUAN on 26 Feb 2002 Single user licence only Storage, distribution or use on network prohibited The interdependency of variables can be shown as follows: A2.2 Deflection limits for rectangular duct Maximum deflection for rectangular duct is shown below Joint: Reinfor.: mm mm Duct dimension mm Deflection limit mm Up to 300 301 to 450 451 to 600 over 600 10.0 12.0 15.0 20.0 NOTE: Maximum deflection for joints and reinforcement shall not exceed mm The maximum test pressure for rectangular ducts is as follows: (a) Laboratory class rating + 50% (b) Field class rating + 25% COPYRIGHT AS 4254—1995 80 APPENDIX B ‘J’ AND ‘I’ REINFORCEMENT RELATED TO ‘EI’ VALUES (Informative) Licensed to LUU MINH LUAN on 26 Feb 2002 Single user licence only Storage, distribution or use on network prohibited Reinforcement EI value ‘J’ ‘I’ × 10 J1 I1 0.5 J2 I2 1.0 J3 I3 2.5 J4 I4 J5 I5 10 J6 I6 15 J7 I7 25 J8 I8 50 J9 I9 75 J10 I10 100 J11 I11 150 J12 I12 200 NOTE: For steel the rigidity index (EI value) is given above in the imperial unit form and is calculated using a factor of 697 × Ix metric moment of inertia (10 mm 4) This enables a direct comparison of SMACNA EI values for any metric shape or section used COPYRIGHT 81 APPENDIX AS 4254—1995 C ALLOWABLE LOADS FOR TRAPEZE ANGLES (Normative) Licensed to LUU MINH LUAN on 26 Feb 2002 Single user licence only Storage, distribution or use on network prohibited For allowable loads for trapeze angles, see Table C1 NOTES: Bending stress is calculated as follows: Deflection is calculated as follows: Shear stress is calculated as follows: FIGURE C1 TRAPEZE LOAD COPYRIGHT Licensed to LUU MINH LUAN on 26 Feb 2002 Single user licence only Storage, distribution or use on network prohibited AS 4254—1995 82 TABLE C1 LOADS FOR TRAPEZE ANGLES Angle Length mm 25 × 25 × 1.6 25 × 25 × 3.0 40 × 40 × 1.6 40 × 40 × 3.0 40 × 40 × 5.0 40 × 40 × 6.0 or 50 × 50 × 3.0 50 × 50 × 5.0 50 × 50 × 6.0 65 × 65 × 5.0 65 × 65 × 6.0 Load, kg 450 36 68 82 159 231 295 426 558 680 889 600 34 68 82 159 231 295 426 558 680 889 750 32 68 82 159 231 295 426 558 680 889 900 27 59 73 154 227 281 417 544 671 880 1050 18 50 64 145 218 277 408 540 667 876 1200 — 36 50 132 204 263 395 526 653 862 1350 — 18 32 113 181 245 381 508 635 844 1500 — — — 86 159 222 354 481 608 817 1650 — — — 45 123 181 318 455 572 780 1800 — — — — 86 145 281 408 535 744 1950 — — — — 36 95 227 358 485 694 2100 — — — — — 36 172 299 426 635 2400 — — — — — — — 145 272 481 2700 — — — — — — — — 68 277 NOTES: It is assumed that steel with a yield strength of 173 MPa or greater is used Loads above assume that a hanger rod is a maximum of 150 mm from duct side If rod is 50 mm away from the duct, allowable load increases All dimensions of angles in accordance with AS 3679 COPYRIGHT 83 AS 4254—1995 APPENDIX D CIRCULAR EQUIVALENT OF RECTANGULAR DUCTS Licensed to LUU MINH LUAN on 26 Feb 2002 Single user licence only Storage, distribution or use on network prohibited (Informative) Sides of rectangular duct 100 125 150 175 200 225 250 275 300 350 millimetres 400 450 500 550 600 650 700 750 800 — — — — — — — — — — — 492 518 543 567 589 610 630 649 686 719 751 780 808 835 860 885 908 930 952 973 993 1013 1031 1050 1068 1085 1102 1119 1135 — — — — — — — — — — — — — — — — — — — — — — — — — — — — — 547 573 598 622 644 666 687 726 762 795 827 857 886 913 939 964 988 1012 1034 1055 1076 1097 1116 1136 1154 1173 1190 1208 — — — — — — — — — — — — 601 628 653 677 700 722 763 802 838 872 904 934 963 991 1018 1043 1068 1092 1115 1137 1159 1180 1200 1220 1240 1259 1277 — — — — — — — — — — — — — 656 683 708 732 755 799 840 878 914 948 980 1011 1041 1069 1096 1122 1147 1172 1195 1218 1241 1262 1283 1304 1324 1344 — — — — — — — — — — — — — — 711 737 763 787 833 876 916 954 990 1024 1057 1088 1118 1146 1174 1200 1226 1251 1275 1299 1322 1344 1366 1387 1408 — — — — — — — — — — — — — — — 765 792 818 866 911 953 993 1031 1066 1100 1133 1164 1195 1224 1252 1279 1305 1330 1355 1379 1402 1425 1447 1469 — — — — — — — — — — — — — — — — 820 847 897 944 988 1030 1069 1107 1143 1177 1209 1241 1271 1301 1329 1356 1383 1409 1434 1459 1483 1506 1529 — — — — — — — — — — — — — — — — — 875 927 976 1022 1066 1107 1146 1183 1219 1253 1286 1318 1348 1378 1406 1434 1461 1488 1513 1538 1562 1586 — — — — — — — — — — — — — — — — — — 984 1037 1086 1133 1177 1220 1260 1298 1335 1371 1405 1438 1470 1501 1532 1561 1589 1617 1644 1670 1696 — — — — — — — — — — — — — — — — — — — 1093 1146 1196 1244 1289 1332 1373 1413 1451 1488 1523 1558 1591 1623 1655 1685 1715 1744 1772 1800 — — — — — — — — — — — — — — — — — — — — 1202 1256 1306 1354 1400 1444 1486 1527 1566 1604 1640 1676 1710 1744 1776 1808 1839 1869 1898 — — — — — — — — — — — — — — — — — — — — — 1312 1365 1416 1464 1511 1555 1598 1640 1680 1719 1756 1793 1828 1862 1896 1929 1961 1992 — — — — — — — — — — — — — — — — — — — — — — 1421 1475 1526 1574 1621 1667 1710 1753 1793 1833 1871 1909 1945 1980 2015 2048 2081 — — — — — — — — — — — — — — — — — — — — — — — 1530 1584 1635 1684 1732 1778 1822 1865 1906 1947 1986 2024 2061 2097 2133 2167 — — — — — — — — — — — — — — — — — — — — — — — — 1640 1693 1745 1794 1842 1889 1933 1977 2019 2060 2100 2139 2177 2214 2250 — — — — — — — — — — — — — — — — — — — — — — — — — 1749 1803 1854 1904 1952 1999 2044 2088 2131 2173 2213 2253 2292 2329 — — — — — — — — — — — — — — — — — — — — — — — — — — 1858 1912 1964 2014 1063 2110 2155 2200 2243 2285 2327 2367 2406 — — — — — — — — — — — — — — — — — — — — — — — — — — — 1968 2021 2073 2124 2173 2220 2266 2311 2355 2398 2439 2480 — — — — — — — — — — — — — — — — — — — — — — — — — — — — 2077 2131 2183 2233 2283 2330 2377 2422 2466 2510 2552 100 109 — — — — — — — — — — 125 150 175 200 225 250 275 300 350 400 450 500 550 600 650 700 750 800 900 1000 1100 1200 1300 1400 1500 1600 1700 1800 1900 2000 2100 2200 2300 2400 2500 2600 2700 2800 2900 122 133 143 152 161 169 176 183 195 207 217 227 236 245 253 261 268 275 289 301 313 324 334 344 353 362 371 379 387 395 402 410 417 424 430 437 443 450 456 137 150 161 172 181 190 199 207 222 235 247 258 269 279 289 298 306 314 330 344 358 370 382 394 404 415 425 434 444 453 461 470 478 486 494 501 509 516 523 — 164 177 189 200 210 220 229 245 260 274 287 299 310 321 331 341 350 367 384 399 413 426 439 452 463 475 485 496 506 516 525 534 543 552 560 569 577 585 — — 191 204 216 228 238 248 267 283 299 313 326 339 351 362 373 383 402 420 437 453 468 482 495 508 521 533 544 555 566 577 587 597 606 616 625 634 643 — — — 219 232 244 256 266 286 305 321 337 352 365 378 391 402 414 435 454 473 490 506 522 536 551 564 577 590 602 614 625 636 647 658 668 678 688 697 — — — — 246 259 272 283 305 325 343 360 375 390 404 418 430 442 465 486 506 525 543 559 575 591 605 619 633 646 659 671 683 695 706 717 728 738 749 — — — — — 273 287 299 322 343 363 381 398 414 429 443 457 470 494 517 538 558 577 595 612 629 644 660 674 688 702 715 728 740 753 764 776 787 798 — — — — — — 301 314 339 361 382 401 419 436 452 467 482 496 522 546 569 590 610 629 648 665 682 698 713 728 743 757 771 784 797 810 822 834 845 — — — — — — — 328 354 378 400 420 439 457 474 490 506 520 548 574 598 620 642 662 681 700 718 735 751 767 782 797 812 826 840 853 866 879 891 — — — — — — — — 383 409 433 455 477 496 515 533 550 567 597 626 652 677 701 724 745 766 785 804 823 840 857 874 890 905 920 935 950 964 977 — — — — — — — — — 437 464 488 511 533 553 573 592 609 643 674 703 731 757 781 805 827 849 869 889 908 927 945 963 980 996 1012 1028 1043 1058 COPYRIGHT 900 1000 1100 1200 1300 1400 1500 1600 1700 1800 1900 AS 4254 — 1995 84 APPENDIX E WEIGHTS AND AREAS OF RECTANGULAR GALVANIZED STEEL DUCTS (Informative) Width plus height Metal thickness, mm 2.0 0.5 0.6 0.8 1.0 1.2 1.6 250 275 300 2.28 2.53 2.76 2.90 3.19 3.48 3.66 4.03 4.39 4.59 5.05 5.51 5.80 6.38 6.96 7.32 9.20 8.06 10.11 8.79 11.03 50 55 60 325 350 375 2.99 3.22 3.45 3.77 4.06 4.35 4.76 5.13 5.49 5.97 6.43 6.89 7.54 9.52 11.96 8.12 10.25 12.88 8.70 10.99 13.80 65 70 75 400 425 450 3.68 3.91 4.14 4.64 4.93 5.22 5.86 6.23 6.59 7.35 9.28 11.72 14.71 7.81 9.89 12.45 15.63 8.27 10.44 13.18 16.56 80 85 90 475 500 525 4.37 4.60 4.83 5.51 5.80 6.09 6.96 7.32 7.69 8.79 11.02 13.91 17.48 9.19 11.60 14.65 18.40 9.65 12.18 15.38 19.31 95 1.00 1.05 550 575 600 5.06 5.29 5.51 6.38 6.67 6.96 8.06 10.11 12.76 16.11 20.23 8.42 10.56 13.34 16.84 21.16 8.79 11.02 13.92 17.58 22.08 1.10 1.15 1.20 650 700 750 5.97 6.43 6.89 7.54 9.52 11.94 15.08 19.04 23.92 8.12 10.25 12.86 16.24 20.51 25.76 8.70 10.99 13.78 17.40 21.27 27.60 1.30 1.40 1.50 800 850 900 7.35 9.28 11.72 14.70 18.56 23.43 29.44 7.81 9.86 12.45 15.62 19.72 24.90 31.27 8.27 10.44 13.18 16.54 20.88 26.37 33.11 1.60 1.70 1.80 950 1000 1050 8.73 11.03 13.91 17.45 22.04 27.83 34.95 9.19 11.61 14.65 18.37 23.20 29.29 36.79 9.95 12.19 15.38 19.29 24.36 30.76 38.63 1.90 2.00 2.10 1100 1150 1200 10.11 12.77 16.11 20.21 25.52 32.22 40.47 10.57 13.35 16.84 21.18 26.68 33.69 42.31 11.03 13.93 17.58 22.05 27.84 35.15 44.15 2.20 2.30 2.40 1250 1300 1350 11.49 14.51 18.31 22.97 29.00 36.62 45.99 11.95 15.09 19.04 23.89 30.16 38.08 47.83 12.41 15.67 19.77 24.80 31.32 39.55 49.67 2.50 2.60 2.70 1400 1450 1500 12.87 16.25 20.51 25.72 32.48 41.01 51.51 13.33 16.83 21.24 26.64 33.64 42.48 53.35 13.79 17.41 21.97 27.56 34.80 43.94 55.19 2.80 2.90 3.00 1550 1600 1650 14.25 17.99 22.70 28.48 35.96 45.51 57.03 14.71 18.57 23.44 29.40 37.12 46.87 58.87 15.17 19.15 24.17 30.32 38.28 48.34 60.71 3.10 3.20 3.30 1700 1750 1800 15.68 19.73 24.90 31.24 39.44 49.80 62.55 16.09 20.31 25.63 32.15 40.60 51.27 64.39 16.54 20.89 26.37 33.07 41.76 52.73 66.23 3.40 3.50 3.60 1850 1900 1950 17.00 21.47 27.10 33.99 42.92 54.20 68.07 17.46 22.05 27.83 34.91 44.08 55.66 69.91 17.92 22.63 28.56 35.83 45.24 57.12 71.75 3.70 3.80 3.90 2000 18.38 23.21 29.29 36.75 46.40 58.59 73.59 4.00 mm Licensed to LUU MINH LUAN on 26 Feb 2002 Single user licence only Storage, distribution or use on network prohibited Area square metres per linear metre NOTE: Weights include 20% allowance for bracing, hangers, waste and seams COPYRIGHT 85 AS 4254 — 1995 APPENDIX F WEIGHTS AND AREAS OF CIRCULAR GALVANIZED STEEL DUCTS (Informative) Metal thickness, mm Diameter 0.5 0.6 0.8 1.0 1.2 1.6 2.0 100 125 150 1.44 1.80 2.17 1.82 2.28 2.73 2.30 2.88 3.45 2.89 3.61 4.38 3.64 4.56 5.47 4.60 5.75 6.90 5.78 7.22 8.67 31 39 47 175 200 225 2.53 2.89 3.25 3.19 3.65 4.10 4.03 4.60 5.18 5.05 5.77 6.49 6.38 8.05 10.11 7.29 9.20 11.56 8.20 10.35 13.00 55 63 71 250 275 300 3.61 3.97 4.33 4.56 5.01 5.47 5.75 6.33 6.90 7.22 9.11 11.50 14.45 7.94 10.02 12.65 15.89 8.66 10.93 13.80 17.34 79 86 94 325 350 375 4.69 5.05 5.41 5.92 6.38 6.84 7.48 9.38 11.84 14.95 18.78 8.05 10.10 12.76 16.11 20.23 8.63 10.82 13.67 17.26 21.67 1.02 1.10 1.18 400 425 450 5.78 6.14 6.50 7.29 9.20 11.54 14.58 18.41 23.12 7.75 9.78 12.27 15.49 19.56 24.56 8.20 10.35 12.99 16.40 20.71 26.01 1.26 1.33 1.40 475 500 525 6.86 7.22 7.58 8.66 10.92 13.71 17.31 21.86 27.45 9.11 11.50 14.43 18.22 23.01 28.90 9.57 12.08 15.15 19.13 24.16 30.34 1.49 1.57 1.65 550 575 600 7.94 10.08 12.65 15.87 20.04 25.31 31.79 8.30 10.48 13.28 16.59 20.96 26.46 33.23 8.66 10.94 13.80 17.32 21.87 27.61 34.68 1.73 1.80 1.88 625 650 675 9.02 11.39 14.38 18.04 22.78 28.76 36.12 9.38 11.85 14.96 18.76 23.69 29.91 37.57 9.75 12.30 15.53 19.48 24.60 31.06 39.01 1.96 2.04 2.12 700 725 750 10.11 12.76 16.11 20.20 25.51 32.31 40.46 10.47 13.22 16.68 20.92 26.42 33.36 41.90 10.83 13.67 17.26 21.65 27.33 34.51 43.35 2.20 2.28 2.36 775 800 825 11.19 14.13 17.83 22.37 28.24 35.66 44.79 11.55 14.58 18.41 23.09 29.15 36.81 46.24 11.91 15.04 18.98 23.81 30.07 37.96 47.68 2.43 2.51 2.59 850 875 900 12.27 15.49 19.56 24.53 30.98 39.11 49.13 12.63 15.95 20.13 25.25 31.89 40.26 50.57 12.99 16.41 20.71 25.97 32.80 41.41 52.01 2.67 2.75 2.83 925 950 975 13.35 16.86 21.28 26.70 33.71 42.56 53.46 13.72 17.32 21.86 27.42 34.62 43.71 54.90 14.08 17.77 22.43 28.14 35.53 44.85 56.36 2.91 2.98 3.06 1000 14.44 18.23 23.01 28.86 36.44 46.01 57.79 3.14 mm Licensed to LUU MINH LUAN on 26 Feb 2002 Single user licence only Storage, distribution or use on network prohibited Area square metres per linear metre NOTE: Weights include 20% allowance for bracing, hangers, waste and seams COPYRIGHT ... Single user licence only Storage, distribution or use on network prohibited Australian Standard ® Ductwork for air- handling systems in buildings First published as AS 4254 — 1995 Incorporating:... part of an air- handling system, intended for the passage of air from one part of an air- handling system to another (See also definition of ‘plenum’) 1.5.11 Duct liner — internal lining of duct... for rectangular duct construction NOTES: Joint reinforcements are classified as ‘J’ for joint with ratings of to 12 (see Appendix B for EI values) Intermediate reinforcements are classified as