BIM-MEP AUS PRACTICES

Transcription

1 BIM-MEP AUS PRACTICES Issued By: BIM-MEP AUS 30 Cromwell Street, Burwood 3205 VIC Australia Revision: Initial Release Date

2 Acknowledgements BIM-MEP AUS acknowledges the contributions of those organisations involved in the development and review of this document including principal contributors: A.G. Coombs Pty Ltd CSR Building Products Ltd D&E Air conditioning Pty Ltd Ductmakers Pty Ltd Fletcher Insulation Pty Ltd Insulation Council of Australia and New Zealand Kavanagh Industries Pty Ltd Knauf Insulation Pty Ltd Marshall Day Acoustics Pty Ltd Norman Disney & Young Pty Ltd Resonate Acoustics Australian Chamber of Commerce and Industry Formatting conventions In addition to standard text formatting for Section and Clause Headings, Table Headings, etc the table below shows other text formats that are used in BIM-MEP AUS Standards and reference documents and their application: Text Type Example Indicates Normal italicized text BIM Execution Plan The generic title for a type of document Bold italicised text BIM-MEP AUS Specification The name of a specific referenced document or standard or term Dark red text LOD First reference to a term or abbreviation that is defined in the website glossary under Practices Blue text Hyperlink/weblink Blue italicised text Explanatory notes Specification explanatory notes or reference information Green text Future Develop This indicates sections or requirements which are still under development but planned to be included within BIM-MEP AUS KEEPING BIM-MEP AUS UP-TO-DATE BIM-MEP AUS software and model content is regularly updated to reflect changes in legislation, technology and industry practice. Feedback and suggestions in relation to the standards via the BIM-MEP AUS website are welcome. Updates to software and content are managed and delivered through the BIM-MEP AUS website to registered BIM- MEP AUS users. LIABILITY DISCLAIMER BIM-MEP AUS makes no warranty, expressed or implied, including but not limited to any implied warranties of merchantability and fitness for a particular purpose, nor assume any legal liability or responsibility for the accuracy, completeness, or usefulness of the information in this document. In no event shall BIM-MEP AUS or its agents be liable for damages or losses resulting from your use of, or reliance on the information provided in this document. COPYRIGHT BIM-MEP AUS All rights reserved. BIM-MEP AUS Page 2

3 Table of Contents 1 INTRODUCTION Scope References Objectives MODEL WORKFLOW Model workflow Ductwork Systems, Services and Specifications Ductwork System Schematics Design Model Construction Model Commissioned As-Built Model RELEVANT STANDARDS DUCTWORK INSULATION DUCTWORK LININGS LINING AND INSULATION CODES General Codes Insulation Wrap /Lining Schedules DRAFTING STANDARDS...15 BIM-MEP AUS Page 3

4 1 INTRODUCTION 1.1 Scope This document sets out the BIM-MEP AUS specification for rigid ductwork linings and insulation wraps. The specification addresses: Ductwork internal acoustic and thermal insulation linings Ductwork external insulation wraps. Fire resistance systems including fire resistance wraps and sprays are nominated in the BIM-MEP AUS Fire Rated Ductwork Systems Specification. 1.2 References This specification should be read in conjunction with the following specifications and documents: BIM-MEP AUS Rigid Ductwork Specification this specification specifies the requirements for rigid rectangular and round ductwork for air handling systems; BIM-MEP AUS Fire Rated Ductwork Systems Specification this specification specifies the requirements for fire resistant ductwork; BIM-MEP AUS Airside Systems, Plant and Equipment Schedule this Excel based schedule provides the complete listing of ductwork systems, plant and equipment names as well as designation of ductwork system colours; BIM-MEP AUS Master Shared Parameter Schedule this document provides the reference for all shared parameter names used within the BIM-MEP AUS IFM and MCM models the Excel formatted schedule provides the Revit classification and GUID for each parameter; and BIM-MEP AUS Template Add-in this template provides the templated services for the insulation wraps and internal linings. These documents can be accessed through the BIM-MEP AUS website. 1.3 Objectives Benefits sought through the development and implementation of this specification include: A structured approach to the specification and modelling of ductwork lining and insulation requirements; Reliable and accurate Design-to-Fabrication workflows; and Industry standardization delivering improved supply chain efficiency, reduced project costs and risks. BIM-MEP AUS Page 4

5 2 MODEL WORKFLOW 2.1 Model workflow This standard supports the implementation of the Design to As-Built workflow that sees the progressive development of the MEP model through to an as-built status. The BIM-MEP AUS constructible Revit template add-in is intended to support a range of design and construction activities including system and engineering checks, construction planning, scheduling and BIM to Field workflows. BIM-MEP AUS design models nominate systems and services and whilst not providing shop drawing level detailing, are fully specified and constructible. BIM-MEP AUS Revit construction models provide construction level detailing and manufacturer s certified content suitable for approval submissions. The ductwork component of the model includes insulation and lining types and should be read in conjunction with the duct fabricators manufacturing specifications to determine code and design compliance. BIM-MEP AUS Commissioned As-Built Models incorporating any field installation changes provide the basis for future design and documentation of modifications to the installation and the ongoing management of accurate as-built records through the building s life cycle. Export of the constructible Autodesk Revit MEP ductwork model to the Autodesk Fabrication Suite allows the ductwork to be detailed for fabrication and site installation set-out. This process adds further detail to the model including: Piece marking Ductwork reinforcement and fabrication data Hanger and penetration site set outs. BIM-MEP AUS Page 5

6 2.2 Ductwork Systems, Services and Specifications A key feature of the BIM-MEP AUS approach to ductwork modelling is the use of defined ductwork systems, services and specifications. This approach draws from the Autodesk Fabrication approach to modelling and is important if the full potential of constructible Revit MEP modelling workflows are to be leveraged by designers and constructors. Systems define the type of reticulation system: Supply Air System, Smoke Spill System, Clean Air System, etc. Services set the system type, applicable specification and routing preferences. Specifications detail the quality standards for each ductwork, insulation and lining type. In BIM-MEP AUS the system and service must be selected to both model the system and nominate the required ducting, insulation and lining specifications. The use of this modelling approach provides significant benefits for downstream engineering validation, coordination and scheduling take-offs. 2.3 Ductwork System Schematics Ducting system design should begin with the system schematics and functional control strategies. These are key to conveying the design intent and are also the starting point for the modelling of the ductwork layouts. Best practice air side schematics convey the system architecture and include: Building compartmentation Smoke and fire rated walls Duct sizes and design flows Monitoring and control strategies. The BIM-MEP AUS template is not intended to generate the schematic from the design model. 2.4 Design Model The BIM-MEP AUS Revit Template allows engineers and modellers to design and specify systems using constructible ducting services. Design ducting service specifications are based on AS and connect plant, equipment and fittings to form complete systems. It is important that the ductwork and insulation be modelled by both system and service specification if it is to be fully leveraged within the Design to Commissioned As-built workflow. The use of BIM-MEP AUS constructible services allows a range of engineering checks and calculations to be completed with greater accuracy. The aim is to support the following engineering tasks: Design flow calculations; Estimation of design flow system pressure losses; and Review of ducting system specification compliance. BIM-MEP AUS Page 6

7 2.5 Construction Model The virtual build of the design model into the LOD 400 construction model generates a model that is suitable for approval submissions and includes all ductwork systems fully designated in terms of system type, service and specification. The development of the design model to the LOD 400 construction model typically involves a number of tasks: Breaking the ductwork into segment lengths; Value engineering to determine the most cost effective service and layout within specification; Changing-out of the design content with manufacturer s certified content for end of line plant and equipment such as fan coil units and fans; Checking option costs against original estimates and/or budget; Final services coordination and routing; and System engineering checks and finalisation of pressure loss calculations and fan selections. Once the construction model is finalized and required approvals received it is possible to convert the model to a Fabrication Model for: Procurement scheduling Final hanger layout and site layout Generation of CAM files for manufacture. 2.6 Commissioned As-Built Model The generation of the LOD 500 model from the approved LOD400 typically involves up-dating the model with BIM-to Field information returned from the field. BIM-MEP AUS Page 7

8 3 RELEVANT STANDARDS There are a number of requirements in the National Construction Code as well as Australian standards that relate to ductwork lining and insulation. Codes and standards referenced in this specification include: General Requirements NCC/ BCA : National Construction Code / Building Code of Australia Ductwork AS : Ductwork for air-handling systems in buildings - Part 2: Rigid duct. AS : The use of ventilation and air conditioning in buildings Part 1: Fire and Smoke Control in multi-compartment buildings AS : The use of ventilation and air conditioning in buildings Part 2: Mechanical Ventilation in buildings Insulation AS AS : Thermal Insulation of pipework, ductwork and equipment Selection, installation and finish : Thermal resistance of insulation for ductwork used in building air conditioning. AS/NZS : Materials for the thermal insulation of buildings - General criteria and technical provisions. Testing AS AS : Methods of fire tests on building materials, components and structures - Simultaneous determination of ignitability, flame propagation, heat release and smoke release : Methods for fire tests on building materials, components and structures - Fire-resistance test of elements of construction AS/NZS : Materials for the thermal insulation of buildings - General criteria and technical provisions UL : Factory-Made Air Ducts and Air Connectors BIM-MEP AUS Page 8

9 4 DUCTWORK INSULATION Insulation applied to the external surface of the ductwork serves the principal purposes of: reducing thermal energy gains or losses assuring system efficiency and uniform supply air temperature across a system, and minimization of condensation risk. Minimum ductwork thermal insulation performance is nominated by the BCA with the required R values determined by a combination of system type, climatic zone and ductwork location. For all zones, except Alpine Zone 8, the insulation requirements within the BCA have been aligned as set out in Table Table BCA Required Thermal R Ratings for insulation ratings (except Zone 8 Alpine) Ductwork Location R-Value Within a conditioned space 1.2 All other locations within the building envelope 2.0 Where exposed to direct sunlight 3.0 The BCA also requires that ductwork insulation: comply with the fire hazard properties set out in AS 4254 and AS1668.1, and for cold air ductwork systems, incorporate a vapour barrier on the outside surface of the insulation. To meet these requirements, the majority of ductwork insulation wrap products are manufactured from kg/m 3 glass wool with a foil facing providing the required vapour barrier. The glass wool insulation thickness required to achieve R1.2. is typically of the order of 38 to 40mm whilst for R2.0 the required thickness is generally 75mm. It is noted these insulation wrap products are not suitable for ductwork exposed to weather or sunlight and hence R3.0 insulation wrap is not typically available. Polyester wool provides an alternative product choice to glass wool with respect to the bulk insulation material, however it is noted that this product has a lower thermal resistance value and hence is typically thicker to achieve the required R value. Stone wool (Rockwool ) is a fully imported product and hence should not be specified except where the higher temperature rating of stone wool is required. BIM-MEP AUS Page 9

10 5 DUCTWORK LININGS Ductwork linings are applied to the internal surface of the ductwork and are typically used where: In-duct noise attenuation is required; and/or Ductwork is exposed to view and/or the weather. The use of internal lining impacts the ductwork fabrication to a significant extent and hence there is a need to integrate the lining specification with the ductwork manufacturing fabrication specifications. Ductwork lining thermal insulation values are nominated by the BCA with the required minimum R values determined by the system type, climatic zone and ductwork location. Table 5.1 BCA Required Thermal R Ratings for Internal Linings (except for Zone 8 Alpine) Location R-Value Within a conditioned space 1.2 All other locations within the building envelope 2.0 Where exposed to direct sunlight 3.0 The BCA also requires that ductwork insulation: comply with the fire hazard properties set out in AS 4254 and AS1668.1, and for cold air ductwork systems, incorporate a vapour barrier on the outside surface of the insulation. Ductwork linings for smoke spill and kitchen exhaust systems and sub-ducts are also required to be faced with perforated metal in order to comply with AS The preferred basis of design for ductwork internal linings is 32kg/m 3 glass wool. This product density provides tested acoustic performance that meets the majority of project requirements. The standard range of industry lining facings are: Heavy Duty Perforated Foil Continuous Acoustic Membrane preferred for general acoustic applications preferred where the surface is required to be cleaned and/or high levels of fibre containment are required. Representative Products include: Acoustituff (CSR - Bradford) VapaStop (Fletcher Insulation) Perforated Metal with Continuous Acoustic Membrane preferred for trafficable ductwork and/or where required for compliance with AS smoke exhaust and kitchen exhaust systems. BIM-MEP AUS Page 10

11 There are a number of proprietary facings that may also be suitable for specific applications, including Premium Acoustic Fabric ( such as CSR-Bradford Ultraphon ) Bonded Matt Face. It is noted that Mylar facings have been specified for clean room and kitchen exhaust systems in the past, however Continuous Acoustic Membranes products are now generally considered to provide a superior facing for these applications. Further details in relation to the specifications for these facings can be accessed through ICANZ member companies. BIM-MEP AUS Page 11

12 6 LINING AND INSULATION CODES 6.1 General BIM-MEP AUS ductwork linings and insulation specification codes are intended to meet the majority of project requirements. The BIM-MEP AUS coding system incorporates a number of default values that support product standardization and compliance, whilst not limiting opportunities for innovation. The following default values are noted within the coding system: Ductwork Acoustic Linings Standard glass wool density for internal linings: 32kg/m 3 Standard internal lining thicknesses: Ductwork External Insulation Wraps Standard glass wool density for external linings: 22kg. 50mm, 75mm and 100mm for R1.2, R2.0 and R3.0 respectively. Standard external insulation wrap thicknesses: 50mm or 75mm for R1.2 and R2.0 respectively Standard facing: Heavy Duty Foil Where a non-default insulation density or thickness are required - these appear as suffix codes. 6.2 Codes The BIM-MEP AUS codes are as follows Table Lining / Insulation Type Lining/Insulation Wrap Type Code External Insulation Wrap IW Duct Acoustic Liner AL Table Material Codes - Insulation Material Code Glass wool GW Polyester PE Stone Wool SW BIM-MEP AUS Page 12

13 Table Material Codes - Density Density kg/m 3 Code 18 18KG 22 22KG 24 24KG 32 32KG 48 48KG Note 1 : Default Values: For external insulation 22Kg/m 3 / For acoustic linings 32Kg/m 3. Table Facing Codes Facing Heavy Duty Perforated Foil Continuous Acoustic Membrane Perforated Metal / CAM Premium Acoustic Fabric Bonded Matt Face Facing Code HDP CAM PMM PAF BMF Table Lining and Insulation Thermal Resistance Codes and thicknesses Lining Thermal Resistance K m 2 /W Code Nominal Thickness mm 1.2 R1.2 50mm 2.0 R2.0 75mm 3.0 R mm Insulation Wrap Thermal Resistance K m 2 /W Code Nominal Thickness mm 1.2 R1.2 50mm 2.0 R2.0 75mm BIM-MEP AUS Page 13

14 6.3 Insulation Wrap /Lining Schedules The insulation wrap /lining scheduling syntax is as follows: INSULATION WRAP / LINING TYPE INSULATION MATERIAL TYPE, THERMAL RESISTANCE VALUE, FACING TYPE, DENSITY The following provides representative examples of scheduling syntax and codes for a number of industry standard insulation and lining services. IW-PER1.2 AL-GWR1.2CAM AL-GWR2.0PMM External insulation comprising 50mm thick 22kg/m 3 polyester wool faced with heavy duty foil to provide a material R value of 1.2 K m 2 /W Acoustic internal lining comprising 50mm thick 32kg/m 3 glass wool faced with continuous acoustic membrane to provide a material R value of 1.2 K m 2 /W Acoustic internal lining comprising 75mm thick 32kg/m 3 glass wool faced with heavy duty perforated metal with continuous acoustic membrane to provide a material R value of 2.0 K m 2 /W A representative example of scheduling code for a non-standard insulation and lining service is as follows. AL-GWR1.2CAM48KG Acoustic internal lining using 50mm thick special order 48kg/m 3 glass wool faced with continuous acoustic membrane to provide an overall R value of 1.2 K m 2 /W BIM-MEP AUS Page 14

15 7 DRAFTING STANDARDS The BIM-MEP AUS Template Add-In provides standard representations for internal linings and insulation wraps that combine established design and shop drawing practices to enable clear indication of the requirements at all points through the design to as-built workflow. The hatching type indicates the type of insulation wrap or lining as follows: External Insulation Wrap single hatch Internal Lining with non-perforated metal facing Internal Lining with perforated metal facing The requirements with respect to the insulation specification are coded noting that the IW or AL code is not required due to the use of the hatching indicating the type. Differentiation of the perforated metal lining requirement has been provided due to the significant impacts that this requirement has with respect to ductwork manufacture and cost. BIM-MEP AUS Page 15