� BIM-MEPAUS PRACTICES

Ductwork Lining and Insulation Wrap Specification

Issued By: BIM-MEPAUS

30 Cromwell Street, Burwood 3205 VIC Australia

Revision: Initial Release

Date January 2016

BIM-MEPAUS

Ductwork Lining and Insulation Wrap Specification

BIM-MEPAUS Page 2

January 2016

Acknowledgements BIM-MEPAUS 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-MEPAUS 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-MEPAUS 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 www.bimmepaus.com.au 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-MEPAUS

KEEPING BIM-MEPAUS UP-TO-DATE BIM-MEPAUS 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-MEPAUS website are welcome.

Updates to software and content are managed and delivered through the BIM-MEPAUS website to registered BIM-

MEPAUS users.

LIABILITY DISCLAIMER

BIM-MEPAUS 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-MEPAUS 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-MEPAUS All rights reserved.

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Table of Contents

1 INTRODUCTION .............................................................................................................. 4

1.1 Scope ........................................................................................................................................................ 4

1.2 References ................................................................................................................................................ 4

1.3 Objectives .................................................................................................................................................. 4

2 MODEL WORKFLOW ...................................................................................................... 5

2.1 Model workflow .......................................................................................................................................... 5

2.2 Ductwork Systems, Services and Specifications ....................................................................................... 6

2.3 Ductwork System Schematics ................................................................................................................... 6

2.4 Design Model ............................................................................................................................................ 6

2.5 Construction Model .................................................................................................................................... 7

2.6 Commissioned As-Built Model ................................................................................................................... 7

3 RELEVANT STANDARDS ............................................................................................... 8

4 DUCTWORK INSULATION .............................................................................................. 9

5 DUCTWORK LININGS ....................................................................................................10

6 LINING AND INSULATION CODES ................................................................................12

6.1 General .................................................................................................................................................... 12

6.2 Codes ...................................................................................................................................................... 12

6.3 Insulation Wrap /Lining Schedules .......................................................................................................... 14

7 DRAFTING STANDARDS ...............................................................................................15

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1 INTRODUCTION

1.1 Scope

This document sets out the BIM-MEPAUS 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-MEPAUS

Fire Rated Ductwork Systems Specification.

1.2 References

This specification should be read in conjunction with the following specifications and documents:

• BIM-MEPAUS Rigid Ductwork Specification – this specification specifies the requirements for

rigid rectangular and round ductwork for air handling systems;

• BIM-MEPAUS Fire Rated Ductwork Systems Specification – this specification specifies the

requirements for fire resistant ductwork;

• BIM-MEPAUS 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-MEPAUS Master Shared Parameter Schedule – this document provides the reference for

all shared parameter names used within the BIM-MEPAUS IFM and MCM models – the Excel

formatted schedule provides the Revit classification and GUID for each parameter; and

• BIM-MEPAUS Template Add-in – this template provides the templated services for the insulation

wraps and internal linings.

These documents can be accessed through the BIM-MEPAUS 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.

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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-MEPAUS 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-MEPAUS design models nominate systems and services and whilst not providing shop drawing level

detailing, are fully specified and constructible.

BIM-MEPAUS 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-MEPAUS 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.

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2.2 Ductwork Systems, Services and Specifications

A key feature of the BIM-MEPAUS 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-MEPAUS 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-MEPAUS template is not intended to generate the schematic from the design model.

2.4 Design Model

The BIM-MEPAUS Revit® Template allows engineers and modellers to design and specify systems using

constructible ducting services.

Design ducting service specifications are based on AS 4254-2012 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-MEPAUS 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.

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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.

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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 4254.2 - 2012 : Ductwork for air-handling systems in buildings - Part 2: Rigid duct.

AS 1668.1 -1998 : The use of ventilation and air conditioning in buildings – Part 1: Fire and

Smoke Control in multi-compartment buildings

AS 1668.2 -2012 : The use of ventilation and air conditioning in buildings – Part 2:

Mechanical Ventilation in buildings

Insulation

AS 4426 – 1997 : Thermal Insulation of pipework, ductwork and equipment – Selection,

installation and finish

AS 4508 -1999 : Thermal resistance of insulation for ductwork used in building air

conditioning.

AS/NZS 4859.1-2002 : Materials for the thermal insulation of buildings - General criteria and

technical provisions.

Testing

AS 1530.3-1999 : Methods of fire tests on building materials, components and structures

- Simultaneous determination of ignitability, flame propagation, heat

release and smoke release

AS 1530.4-2005 : Methods for fire tests on building materials, components and structures

- Fire-resistance test of elements of construction

AS/NZS 4859.1-2002 : Materials for the thermal insulation of buildings - General criteria and

technical provisions

UL 181-2005 : Factory-Made Air Ducts and Air Connectors

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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 4.1.1.

Table 4.1.1 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

18-24 kg/m3 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.

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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 1668.1.

The preferred basis of design for ductwork internal linings is 32kg/m3 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 – preferred for general acoustic applications

• Continuous Acoustic Membrane – 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 AS1668.1 smoke

exhaust and kitchen exhaust systems.

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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.

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6 LINING AND INSULATION CODES

6.1 General

BIM-MEPAUS ductwork linings and insulation specification codes are intended to meet the majority of

project requirements.

The BIM-MEPAUS 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/m3

• Standard internal lining thicknesses: 50mm, 75mm and 100mm for R1.2, R2.0 and

R3.0 respectively.

Ductwork External Insulation Wraps

• Standard glass wool density for external linings: 22kg.

• 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-MEPAUS codes are as follows

Table 6.2.1 Lining / Insulation Type

Lining/Insulation Wrap Type Code

External Insulation Wrap IW

Duct Acoustic Liner AL

Table 6.2.2 Material Codes - Insulation

Material Code

Glass wool GW

Polyester PE

Stone Wool SW

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Table 6.2.3 Material Codes - Density

Density kg/m3 Code

18 18KG

22 22KG

24 24KG

32 32KG

48 48KG

Note 1 : Default Values: For external insulation – 22Kg/m3 / For acoustic linings – 32Kg/m3.

Table 6.2.4 Facing Codes

Facing Facing Code

Heavy Duty Perforated Foil HDP

Continuous Acoustic Membrane CAM

Perforated Metal / CAM PMM

Premium Acoustic Fabric PAF

Bonded Matt Face BMF

Table 6.2.5 Lining and Insulation Thermal Resistance Codes and thicknesses

Lining Thermal Resistance K·m2/W Code Nominal Thickness

mm

1.2 R1.2 50mm

2.0 R2.0 75mm

3.0 R3.0 100mm

Insulation Wrap Thermal

Resistance K·m2/W

Code Nominal Thickness

mm

1.2 R1.2 50mm

2.0 R2.0 75mm

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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 External insulation comprising 50mm thick 22kg/m3 polyester wool

faced with heavy duty foil to provide a material R value of 1.2 K·m2/W

AL-GWR1.2CAM Acoustic internal lining comprising 50mm thick 32kg/m3 glass wool

faced with continuous acoustic membrane to provide a material R

value of 1.2 K·m2/W

AL-GWR2.0PMM Acoustic internal lining comprising 75mm thick 32kg/m3 glass wool

faced with heavy duty perforated metal with continuous acoustic

membrane to provide a material R value of 2.0 K·m2/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/m3

glass wool faced with continuous acoustic membrane to provide an

overall R value of 1.2 K·m2/W

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7 DRAFTING STANDARDS

The BIM-MEPAUS 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.