A Guidebook on Insulation

How to save energy and money

Guide Book 6 INSULATION

STRATEGY

ENERGY EFFICIENCY EARNINGS

STRATEGY

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MI E

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3E

Netherlands Ministery of Economic Affairs

EUROPEAN COMMISSION

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TSI

Technical Services International

HOW TO SAVE ENERGY AND MONEY IN INSULATION This booklet is part of the 3E strategy series. It provides advice on practical ways of improving energy efficiency in industrial insulation applications. Prepared for the European Commission DGXVII by: The Energy Research Institute Department of Mechanical Engineering University of Cape Town Rondebosch 7700 Cape Town South Africa Neither the European Commission, nor any person acting on behalf of the commission, nor NOVEM, AEAT, ERI, nor any of the information sources is responsible for the use of the information contained in this publication The views and judgements given in this publication do not necessarily represent the views of the European Commission This project is funded by the European Commission and co-funded by the Dutch Ministry of Economics, the South African Department of Minerals and Energy and Technology Services International (ESKOM), with the Chief contractor being AEAT.

HOW TO SAVE ENERGY AND MONEY IN INSULATION

HOW TO SAVE ENERGY AND MONEY IN INSULATION Other titles in the 3E strategy series: HOW TO SAVE ENERGY AND MONEY: THE 3E STRATEGY HOW TO SAVE ENERGY AND MONEY IN ELECTRICITY USE HOW TO SAVE ENERGY AND MONEY IN BOILERS AND FURNACES HOW TO SAVE ENERGY AND MONEY IN COMPRESSED AIR SYSTEMS HOW TO SAVE ENERGY AND MONEY IN REFRIGERATION HOW TO SAVE ENERGY AND MONEY IN STEAM SYSTEMS Copies of these guides may be obtained from: The Energy Research Institute Department of Mechanical Engineering University of Cape Town Rondebosch 7700 Cape Town South Africa Tel No: (+27 21) 650 3892 Fax No: (+27 21) 686 4838 Email: [email protected] Website: http://www.3e.uct.ac.za

ACKNOWLEDGEMENTS The Energy Research Institute would like to acknowledge the following for their contribution in the production of this guide: . .

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Energy Technology Support Unit (ETSU), UK, for permission to use information from the ªEnergy Efficiency Best Practiceº series of handbooks. Energy Conservation Branch, Department of Energy, Mines and Resources, Canada, for permission to use information from the ªEnergy Managementº series of manuals. TLV co, Ltd, for permission to use figures from their set of handbooks on steam. Wilma Walden of Studio.com for graphic design work ([email protected]). Doug Geddes of South African Breweries for the cover colour photography.

Guide Book Essentials: QUICK `CHECK-LIST' FOR SAVING ENERGY AND MONEY IN INSULATION SYSTEMS This list is a selected summary of energy and cost savings opportunities outline in the text. Many more are detailed in the body of the booklet. These points are intended to be a quick `checklist'. ADDING NEW INSULATION (Chapter 4) 1. Insulate non-insulated pipe. 2. Insulate non-insulated vessels. ADDING EXTRA INSULATION (Chapters 2 and 4) 1. Repair insulation damage. 3. Add insulation to reach recommended thickness. 4. Upgrade existing insulation levels. 5. Review economic thickness requirement. 6. Limited budget upgrade.

Table of Contents 1. INTRODUCTION..................................................................................................................................................................................... 1 2. FUNDAMENTALS..................................................................................................................................................................................... 2 2.1 Terms and definitions...................................................................................................................................................................... 2 2.2 Selection of Insulation Material ................................................................................................................................................. 2 2.2.1 A Note on Asbestos ............................................................................................................................................................ 3 2.3 Heat Transfer ....................................................................................................................................................................................... 4 2.4 Heat Flow ............................................................................................................................................................................................... 4 FIGURE 1: TYPICAL INSULATED PIPE................................................................................................................................. 5 2.5 Protecting and Sealing the Insulation ..................................................................................................................................... 6 2.5.1 Protective Coverings and Finishes.................................................................................................................................. 6 2.5.2 Vapour Barriers ........................................................................................................................................................................ 6 2.6 Temperature Ranges........................................................................................................................................................................ 6 2.6.1 Low Temperature Thermal Insulation ......................................................................................................................... 6 2.6.2 Intermediate Temperature Thermal Insulation........................................................................................................ 7 2.6.3 High Temperature Thermal Insulation......................................................................................................................... 7 2.7 Insulation Thickness.......................................................................................................................................................................... 7 2.7.1 Selection Procedures............................................................................................................................................................. 7 2.7.2 Recommended Insulation Thickness............................................................................................................................. 7 2.7.3 Limited Budget Insulation Thickness ............................................................................................................................. 8 2.7.4 Economic Insulation Thickness......................................................................................................................................... 8 FIGURE 2: DETERMINATION OF ECONOMIC THICKNESS OF INSULATION...................................... 9 FIGURE 3: HEAT LOSS FROM FLAT SURFACE ............................................................................................................ 10 FIGURE 4: COST OF ENERGY LOSS AT VARIOUS INSULATION THICKNESSES................................ 11 FIGURE 5: INSULATION COST AT VARIOUS THICKNESSES ............................................................................ 11 2.8 Energy Management.......................................................................................................................................................................... 12 2.8.1 Energy Audits ............................................................................................................................................................................ 12 2.8.2 Energy Management Opportunities .............................................................................................................................. 12 3 MATERIALS SYSTEMS............................................................................................................................................................................. 13 3.1 Insulation Forms and Materials.................................................................................................................................................. 13 3.1.1 Types and Forms of Insulation ..................................................................................................................................... 13 3.1.2 Major Insulation Materials................................................................................................................................................ 13

3.2 Insulation Systems ............................................................................................................................................................................. 3.2.1 Protective Coverings and Finishes.............................................................................................................................. 3.2.2 Properties of Protective Coverings............................................................................................................................ 3.2.3 Accessories ............................................................................................................................................................................. 3.2.4 Securements .......................................................................................................................................................................... 3.2.5 Insulation Reinforcement for Cement and Mastics........................................................................................... 3.2.6 Water Flashing...................................................................................................................................................................... 3.2.7 Stiffening................................................................................................................................................................................... 3.2.8 Supports................................................................................................................................................................................... 3.2.9 Sealing and Caulking .......................................................................................................................................................... 3.2.10 Expansion and Contraction Compensation.......................................................................................................... 3.3 Common Applications.................................................................................................................................................................... 3.3.1 Multiple Layer Construction.......................................................................................................................................... 3.3.2 Pipe Insulation for Interior Applications.................................................................................................................. FIGURE 6: FIELD AND FACTORY-APPLIED NON-METAL JACKETING ...................................................... 3.3.3 Metal Jacketing ...................................................................................................................................................................... 3.3.4 Flexible Elastomeric Pipe Covering............................................................................................................................ 3.3.5 Fittings Insulation.................................................................................................................................................................. 3.3.6 PVC or Glass Fibre Fitting Insulation........................................................................................................................ FIGURE 7: FIELD APPLIED METAL JACKETING ............................................................................................................ FIGURE 8: FLEXIBLE ELASTOMERIC PIPE COVERING............................................................................................. FIGURE 9: MITRED INSULATION ELBOW OVERSIZED APPLICATION ..................................................... FIGURE 10: PVC/GLASS FIBRE ELBOW INSULATION SYSTEM ........................................................................ 3.3.7 Insulation of In-line Flanges or Couplings............................................................................................................... 3.3.8 Removable and Reusable Insulation.......................................................................................................................... 3.3.9 Duct Insulation ..................................................................................................................................................................... FIGURE 11: PVC/GLASS FIBRE COUPLING OR IN-LINE FLANGE INSULATION SYSTEM.............. FIGURE 12: REMOVABLE AND REUSABLE INSULATION.................................................................................... FIGURE 13: FLEXIBLE FIBROUS BLANKET DUCT INSULATION RECTANGULAR/INDOORS .... 3.3.10 Field Applied Lining............................................................................................................................................................ 3.3.11 Insulation of Tanks and Vessels ................................................................................................................................... FIGURE 14: FIELD APPLIED LINING DUCTS, PLENUMS AND HOUSINGS..............................................

14 15 16 16 16 17 17 17 17 17 17 17 18 18 18 19 19 19 19 19 19 20 20 21 21 21 21 21 22 22 22 22

FIGURE 15: CURVED SURFACES RIGID BOARD INSULATION........................................................................ 22 3.3.12 Vessel and Tank Head Insulation ................................................................................................................................ 23 FIGURE 16: METAL HEAD INSULATION, SECUREMENT AND COVER FABRICATION ................. 23 4 ENERGY MANAGEMENT OPPORTUNITIES ......................................................................................................................... 24 4.1 Housekeeping Opportunities...................................................................................................................................................... 24 4.1.1 Housekeeping Worked Examples.................................................................................................................................. 24 4.2 Low Cost Opportunities............................................................................................................................................................... 25 4.2.1 Low Cost Worked Examples........................................................................................................................................... 25 4.3 Retrofit Opportunities.................................................................................................................................................................... 27 4.3.1 Retrofit Worked Examples ................................................................................................................................................ 27 APPENDICES...................................................................................................................................................................................................... 30 Worksheets ......................................................................................................................................................................................................... 30 Glossary .......................................................................................................................................................................................................... 40 Heat loss tables ................................................................................................................................................................................................. 47 Basic types of insulation ± selected properties.............................................................................................................................. 64 Protective coverings and finishes............................................................................................................................................................ 65 Vapour retarders.............................................................................................................................................................................................. 66 Energy Content of Some Fuels................................................................................................................................................................ 67

1. INTRODUCTION

Thermal insulation is the use of special materials to retard the flow of heat energy. It prevents the loss of heat, so saving on fuel and money, and contributing to safety and comfort. Insulating unlagged hot surfaces is one of the simplest and most cost-effective ways of increasing energy efficiency. Depending on the pipe's surface temperature, the payback time for insulating a section of pipework is typically less than one year.

Refractory materials often need high resistance to abrasion as elevated temperatures. This guide is only about thermal insulation. Insulation materials may come in boards, blocks, bricks, sheets, pre-formed shapes, blankets or as castable cements. The choice of materials depends on cost, temperature, application, environment and safety. The thickness of insulation should be calculated so as to optimise the cost of the insulation against the savings in energy. This guide covers these topics and gives worked examples of costs saved by insulation.

By improving energy efficiency, it is possible to reduce the size of heating, cooling and ventilation equipment and so reduce capital costs. Process temperature control is made easier.

This guide uses metric units throughout but has included some Imperial units, which are still used in some South African plants.

Insulation may be divided roughly into three temperature ranges. Cryogenic temperatures are below 73oC. Thermal insulation is for temperatures from 730oC to 982oC. Refractory insulation is for temperatures above 982oC, as would be found in cement kilns, steelworks and incinerators.

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2. FUNDAMENTALS

2.1 TERMS AND DEFINITIONS

an insulating material. The higher the R values the better the insulation. It should be noted that k, C, U, R can be equated as follows. t l l ˆ ˆ R ˆ k C U

Certain key terms used in this booklet are defined below. A more extensive glossary of terms is included in the appendices. .

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Conduction is the process, by which heat flows from a hot body to a cooler body or fluid, which is in stationary contact with it. Convection is the process, by which heat flows from a hot body to a gas or liquid, which is in moving contact with it. Radiation is the flow of heat from a hot body without it being in contact with a fluid or solid. Thermal Conductivity (k) is a measure of heat energy transmitted through a homogeneous material per unit thickness. A material with a low thermal conductivity is a good insulator. Expressed as W/(m oC) or (Btu/h ft2 oF). Thermal Conductance (C) is a measure of the heat energy transmitted through a homogeneous material of other than unit thickness or through an assembly. Expressed as W/m2.oC) or [Btu/(ft2.hr.oF)]. Thermal Transmittance (U) is a measure of the heat energy transmitted by a material or assembly including the boundary air films. Expressed as W/(m2.K) or [Btu/(h.ft2 oF)]. Thermal Resistance (RSI or R) indicates the relative insulating value or resistance to heat flow of material. Thermal Resistance is the primary consideration in the choice of

Where, t ˆ material thickness (metres or inches) .

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2.2

Mean Temperature is the arithmetic average of the hot and cold insulation surface temperatures through which heat is transmitted. Emissivity is the ratio of heat energy radiated from a surface compared to the heat energy radiated from an ideal black body at the same temperature. Black Body is defined either as a body, which absorbs all radiation falling upon it and reflects or transmits none, or as a radiator, which emits at any specific temperature, the maximum possible amount of thermal radiation.

SELECTION OF INSULATION MATERIAL

The following is a list of important properties, which must be considered in the selection of an insulating material. .

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Thermal Resistance. The higher the value of thermal resistance, the better the insulating capability of the material.

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Combustibility. This becomes significant as it provides an indication of the insulating material's contribution to a fire hazard. Toxicity. Certain insulating materials are combustible and release toxic fumes when they burn. These must be avoided where there is a danger of fire in a confined space. See also the note on asbestos. Shrinkage. Shrinkage or drying is significant in high temperature applications. Shrinkage can leave non-insulated gaps. Resistance to Ultra Violet Radiation. Where the insulating material is exposed to sunlight in outdoor applications, its ability to withstand ultraviolet radiation without degradation is important. This can be overcome by covering the insulating material so that sunlight does not contact the material. Resistance to Fungal or Bacterial Growth. This property is significant in food or cosmetic processing areas. Chemical Neutrality. The insulation should be chemically neutral (pH 7) to avoid any deterioration of metal contacting it. This is particularly important in applications where the insulation could be subject to intermittent wetting. Coefficient of Expansion and Contraction. This property becomes important in the design and location (spacing) of expansion and contraction joints and in multiple layer insulation applications. Compressive Strength. Compressive strength is significant where the insulating material must support a load or withstand mechanical abuse without crushing. When cushioning or filling in space is needed, such as in expansion/contraction joints, low compressive strength materials would normally be specified. Breaking Load. Breaking load is significant in installations where the insulation is

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applied over irregular or non-uniform surfaces where the insulation must ªbridgeº over a support discontinuity. Capillarity. Where insulation material is in contact with dangerous or flammable liquids, or in areas where wash down occurs, the resisting capability of the material to ªwick-upº (absorb) liquids by capillary action becomes significant. Appearance. Appearance is significant in exposed areas and for purposes of identification. Density. The density of an insulating material affects many of its other properties, especially its thermal properties.

Some of these factors may not apply in all insulation applications, however, each should be considered, and ruled out if not applicable. Worksheet 1-1 has been developed as a checklist to assist in establishing which properties are important in a specific application. Properly installed, mechanical insulation will have a life equal to the life of the equipment or piping on which it is installed. Mechanical insulation should always be installed according to the manufacturer's installation recommendations.

2.2.1 A NOTE ON ASBESTOS Asbestos was much used in the past for thermal insulation. However, because asbestos fibres when inhaled can cause lung cancer, it is no longer used for this purpose. Asbestos comes in many kinds, of which the one most commonly used today is chrysotile, one of the least dangerous types. It is believed that there is a threshold below which inhaled chrysotile fibres do no damage to human health. Chrysotile is now used in cement building materials, brake linings and certain other products but not in thermal insulation.

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Asbestos was used as an insulation material not so much because its thermal conductivity is low (in fact, at about 0.06 W/moC, it is higher than many other materials) but because of its non-flammability. Old plants may still have asbestos insulation. It is often safer to seal and leave it than to remove it because the removal can release fibres into the air. This is a matter that requires expert advice from health and safety authorities.

2.3

insulation material is to retard heat flow. The term thermal conductivity (k) is used to express the quantity of heat, which will flow across a unit area when a temperature difference of one degree exists. Thermal conductivity (k), is expressed as Watts per metre per degree Celsius [W/(moC)] or [(Btu)/ (h.ft2 oF)]. Thermal Resistance can now be defined as the opposition of the passage of heat through the insulation and is expressed by the following equation.

HEAT TRANSFER

Thermal Resistance ˆ

Heat is always transferred from a hot body to body at a lower temperature, never the other way round.

t R ˆ [(m. oC)/W] or [(h.ft oF)/Btu] k Where t ˆ insulation thickness [metres or inches].

Heat is lost from hot bodies in three ways: The higher the value of R, the better the insulation. .

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Conduction. Heat is transferred by contact with another solid body or fluid without movement. Convection. Heat is transferred by contact with a moving liquid or gas. Radiation. Heat is transferred without contact with another body or fluid. The heat may be transmitted through a vacuum or through air. The heat is transmitted as electromagnetic radiation (such as infrared radiation). Radiation becomes increasingly important as temperature increases.

The heat flow through the insulation for a flat surface may be calculated using the following equation : Heat flow in one hour ˆ

Where, DT ˆ Temperature difference across the insulating material (oC) A ˆ surface area (m2) As an example, consider a 10m2 flat surface at a temperature of 140oC. This surface has been insulated with a 51 mm thick insulating material having a thermal conductivity of 0.045 W/(m.oC). The outer surface temperature of the insulation is 10oC. The thermal resistance can be determined as follows.

For hot pipes and hot surfaces in factories, most heat is lost by convection. The air in contact with the hot surface heats up, moves off and is replaced by cold air, which is heated up in turn

2.4

DT  A Wh R

HEAT FLOW

R ˆ

t k

0:051 0:045 ˆ 1.133 m.oC/W

The term heat flow refers to the rate at which heat moves from an area of higher temperature to an area of lower temperature. The purpose of any

ˆ

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Now the heat flow in one hour through the insulation can be determined. Heat flow in one hour ˆ ˆ

For example, consider the heat loss from a 1 metre length of 0.219 metre diameter pipe operating at 95oC. The 51 mm thick insulation has a thermal conductivity of 0.037 W/(m.oC) and an outside surface temperature of 25oC. This example is shown in Figure 1. The heat flow through the insulation can be determined as follows.

DT  A R …140

10†  10 1:133

ˆ 1147.4 Wh

r2 ˆ

Heat flow through pipe insulation is somewhat different since the inner and outer surfaces of the insulation have different areas. This difference in area must be taken into account in heat flow calculations. As the heat from the pipe flows outward through the insulation, the area of the heat flow path becomes greater. This phenomenon has the effect of increasing the value of the thermal resistance.

ˆ 0.1605m r1 ˆ

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0:219 2

ˆ 0.1095m R ˆ

r2 ln

r2 r1

k 0:1605  In 0:1605 0:1095 ˆ 0:037

To compensate for this effect an ªequivalent thicknessº of insulation must be used. The expression for the thermal resistance for piping insulation can now be rewritten as follows. R ˆ

0:219 ‡ 0:051 0

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0:1605  …1:466† 0:037

ˆ 1.66 (m2 oC)/W Heat Flow in one hour

equivalent thickness [(m2.oC/W] conductivity r2 ln rr21

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k

DT  A R ˆ

Where, r2 ˆ outside radius of insulation (m)

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r1 ˆ inside radius of insulation (m)

…95

25†  1:008 Wh 1:66

70  1:008 1:66

ˆ 42.51 Wh/metre of length of the pipe

ln ˆ natural logarithm

It must be noted that A in the above equation is the outside surface area of a 1-metre length of the insulated pipe and is calculated as follows. Where, D ˆ 3.14159 D ˆ outside diameter of insulation (pipe outside diameter ‡ 2  insulation thickness) Figure 1: Typical Insulated Pipe (Source: Canadian Govn Pub)

l ˆ unit length (in this case 1 metre)

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Therefore A ˆ   …0:219 2  0:051†  1

Additional details on protective coverings and finishes may be found in the Material/Systems section of this module.

ˆ (  …0:321 :†  1 ˆ 3.14159  0.321 ˆ 1.008 m2

2.5.2

A vapour retarder or vapour barrier is a material, which retards the transmission of water vapour. This is required for piping and equipment operating at below ambient temperatures. Water vapour from the air tends to diffuse into the insulation where, because of the lower temperatures it condenses and significantly reduces the effectiveness of the insulation. Moisture penetration may also cause corrosion of metal surfaces.

2.5 PROTECTING AND SEALING THE INSULATION 2.5.1

VAPOUR BARRIERS

PROTECTIVE COVERINGS AND FINISHES

The efficiency and service life of insulation is directly dependent upon its protection from moisture entry and mechanical and/or chemical damage. Choices of jacketing and finish materials are based upon the mechanical, chemical, thermal and moisture conditions of the installation, as well as cost and appearance.

Vapour barriers are applied on site and may consist of semi-liquid mastic compositions and coating. They may be sprayed, brushed or trowelled. The manufacturer's specified thickness must be applied in one or more continuous coatings. Suitable reinforcement may be required as the vapour barrier system must be adequate to resist cracking.

Protective coverings are divided into six functional types. .

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Weather barriers, which protect the insulation from the effects of weather. Vapour retarders, which are designed to retard the passage of water vapour from the atmosphere to the insulation. Mechanical protection coverings, which protect against mechanical damage from personnel, equipment and machinery. Low flame spread and corrosion resistant coverings, which reduce the effect of flame spread and corrosion. Coverings and finishes are available to enhance the aesthetic appearance of insulated surfaces in highly visible areas. Hygienic covers, which present smooth surfaces to resist fungal and bacterial growth.

TEMPERATURE RANGES

The temperature range within which the term ªthermal insulationº applies, is from 73oC ( 100oF) to 982oC (1800oF). All applications below 73oC ( 100oF) are termed cryogenic and those above 982oC (1800oF) are termed refractory. Thermal insulation is further divided into three general application temperature ranges.

2.6.1

LOW TEMPERATURE THERMAL INSULATION

Insulation used for low temperature applications is subdivided into three general temperature ranges.

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2.6.3

16oC (6OoF) through 0oC (32oF) ± cold or chilled water. -1 o C (31 o F) through 39 o C ( 39 o F) refrigeration or glycol. 40oC ( 40oF) through 73oC ( 100oF) refrigeration or brine.

High temperature thermal insulation is used in the temperature range of 3l5oC (600oF) to 870oC (1600oF). As the refractory range of insulation is approached, fewer materials and application methods are available. High temperature materials are often a combination of other materials or of similar materials manufactured using special binders. Industrial power and process piping and equipment, commercial boilers, exhausts, furnaces and incinerators fall within this application range.

The major problems on low temperature installations are moisture penetration and cost effectiveness. Ideally, the insulation material or system should absorb no moisture and readily give up any that enters. It should also resist water deterioration. Vapour retarders are used extensively, but in practice it is almost impossible to achieve a perfect vapour retarder. The pressure of the vapour flow from the warm outside surface is such that, even with waterproof insulation, vapour may enter through unsealed joints or cracks, condense, then freeze, and cause damage. Vapour retarders must have a perm rating well below 1. The colder the equipment, the lower the desirable perm rating.

2.7

INSULATION THICKNESS

2.7.1

SELECTION PROCEDURES

Although insulating uninsulated areas means immediate returns in Rands saved, sometimes the long-term potential Rand savings are forgotten. Any facility that has not had its insulation upgraded in the past ten years is likely to be under-insulated.

Since the cost of refrigeration is higher than the cost of heating, more insulation is often justified in low temperature applications where 4T is the same. Extra thickness of insulation, even beyond what would be economically dictated for cold line application, are sometimes employed to keep the warm surface temperature above the dew point.

2.6.2

HIGH TEMPERATURE THERMAL INSULATION

Immediate savings can be realised from insulating where no insulation exists. This includes piping, tanks, vessels as well as valves and fittings. With respect to valves and fittings, the insulation would normally be specified to the standards and thickness of the surrounding piping insulation ducting or equipment.

INTERMEDIATE TEMPERATURE THERMAL INSULATION

This temperature range, from 16oC (61oF) to 315oC (600oF) includes conditions encountered in most industrial processes and in hot water and steam systems found in commercial installations. Selection of material in this range is based mainly on thermal values but other factors such as mechanical and chemical properties, availability of forms, installation time and cost are also significant.

2.7.2

RECOMMENDED INSULATION THICKNESS

Tables 1 and 2 have been included in the Appendices and provide data, which is used to perform energy savings, calculations. These tables indicate the heat loss from bare steel pipe and

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bare steel flat surfaces over the range of temperatures normally encountered in most facilities, and are based on an ambient air temperature of 21.1oC.

cost of the insulation. This is necessary to establish the economic thickness of the insulation. One way of improving cost savings through insulation is to upgrade to the insulation levels shown in the recommended thickness tables (Table 3). These should be used as guidelines.

For process applications, tables based on economics have been developed which provide a recommended insulation thickness for various insulating materials and temperatures. Table 3 is a typical table covering mineral fibre, calcium silicate, and cellular glass insulation for pipes varying from NPS 1/2 to NPS 36 in diameter and process temperatures between 65oC and 566oC. These tables also include flat surfaces. (NPS is Nominal Pipe Size measured in inches).

In some cases these tables will not apply as plant or building conditions may not be the same as those used to determine the thickness charts. In these cases, individual determinations of insulation thickness should be considered to insure a facility is making its optimum investment in insulation.

2.7.3

It must be noted for a round tank or vessel with diameter greater than 914 mm, the surface is considered flat for purposes of heat loss calculations.

LIMITED BUDGET INSULATION THICKNESS

Generally for hot mechanical systems, piping will be the source of greatest heat loss. On a limited budget, determine where the area of greatest heat loss is and insulate it first. The first 25mm of insulation will provide the greatest savings in energy on a system but may not be the optimum insulation level for maximising investment benefits. This can also be an excellent approach to cost reductions if insulation is to be paid out of an annual maintenance or operating budget. Bear in mind though, if only the minimum 25mm is applied, the labour component may be the same as if a greater thickness of insulation were used.

As an example of the use of these tables, consider an NPS 6 steel pipe without insulation operating at 121oC in ambient conditions of 21.loC. Table 1 indicates this pipe will lose 700 Wh/linear metre of heat every hour it is in operation. If the recommended thickness of 76 mm of mineral fibre insulation as indicated in Table 3 were installed on this pipe, the heat loss would be reduced to 37 Wh/lineal metre and the outer surface temperature of the insulation would be 23oC. Insulation manufacturers have prepared tables for other materials since the thermal resistance varies both with the material being used and the process temperature. In the event that tables cannot be obtained, heat loss from piping and flat surfaces may be calculated using the equation in the previous section of this module entitled Heat Flow, and R values as selected from Table 4 in the appendix.

2.7.4

ECONOMIC INSULATION THICKNESS

Insulation can be considered a long-term investment with associated financial benefit, following a relatively short initial payback. There are a number of computer programs available to aid in selecting the most economic insulation thickness. This is the thickness, which provides the highest insulation value for the lowest cost.

A series of calculations will have to be performed and the energy savings compared to the installed

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Economics is the primary concern in evaluating investment alternatives. When applied to an insulation system, economics can be used to establish the following items. Evaluation of two or more insulation materials for lowest cost for a given thermal performance. Selection of the optimum insulation thickness for a given insulation type.

not manufactured in single layers of sufficient thickness and/or to alleviate expansion and contraction movements. This results in higher total labour costs than to install one layer equal to the cumulative thickness. Figure 2 is a typical representation of installed costs for a multi-layer application. The average slope of the curves increases with the number of layers because labour and material costs increase at a more rapid rate as insulation thickness increases.

In either case economics is used to determine the most cost effective solution for insulating. Beyond the optimum economic thickness, additional insulation does not yield the maximum rate of return on investment.

The cost of lost energy is directly related to the rate of heat transfer through the insulation and the Rand value of the energy. As also shown in Figure 2, the cost of lost energy decreases as insulation thickness increases.

Material and often labour costs increase with insulation thickness. Insulation must often be applied in multiple layers because materials are

Consider a process application with a flat surface holding a process fluid at 150oC. The ambient temperature is 20oC.

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Figure 2: Determination of Economic Thickness of Insulation (Source: Canadian Govn Pub)

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Calculation of heat loss for 50, 75 and 100 mm of glass mineral fibre insulation with a density of 24 kg/m3 can be performed to establish the heat losses at the various insulation thicknesses. Process temperature: Ambient Temperature: DT:

The surface area will remain constant for the insulation since this is a flat surface. Heat loss can now be evaluated for a typical 1 m2 area for each insulation thickness.

150oC 20oC 150 20 ˆ 130oC

Heat loss in one hour

ˆ 137.86 Wh Heat loss (75 mm insulation)/m 130  1 in one hour ˆ 1:415 ˆ 91.873 Wh

The thermal resistance (R) can be calculated for the various insulation thicknesses using the equation R R50

0:050 ˆ 0.943 ˆ 0:053

R75 ˆ

0:075 ˆ 1.415 0:053

R100 ˆ

0:100 ˆ 1.887 0:053

DT  A R

Heat loss 130  1 (50 mm insulation) in one hour ˆ 0:943

From Table 5 thermal conductivity (k) at a mean temperature of 93.3oC (closest value not exceeding 1300C) is 0.053 W/(m oC).

t ˆ K

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Heat loss (100 mm insulation)/m in one hour

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130  1 Wh 68:89

Using Table 2 it is established that the heat loss from one square metre of the same surface with no insulation would be approximately 2100 Wh/m2. These figures can be plotted on a graph (Figure 3) showing insulation thickness versus heat loss to generate a heat loss curve.

Figure 3: Heat Loss from Flat Surface (Source: Canadian Govn Pub)

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Figure 4: Cost of Energy Loss at Various Insulation Thicknesses (Source: Canadian Govn Pub)

Knowing the value of the heat energy, the cost of lost heat at the various insulation thicknesses can be established by the following equation.

The installed cost of the insulation for the various thicknesses can now be established and a second curve (Figure 5) can be produced.

Rand loss per unit area ˆ Heat loss per unit area  R per unit of heat energy

Figures 4 and 5 may be superimposed and will produce a curve generally of the shape of Figure 2. If the dollar loss and insulation cost curves are combined, and a new curve plotted, the insulation thickness equivalent to the low point on the new curve will be the economical insulation thickness.

Total Rand loss (Figure 4) ˆ Total area  R Loss/unit area  hours/year

Figure 5: Insulation Cost at Various Thicknesses (Source: Canadian Govn Pub)

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installed cost of the added material. The reduction in energy consumption establishes the Rand savings.

2.8 ENERGY MANAGEMENT 2.8.1

ENERGY AUDITS

With this information, simple payback calculations can establish the financial viability of the opportunity.

An energy audit involves the identification of areas throughout a facility where energy may be wasted because of non-existent or inadequate insulation.

2.8.2

The audit may be applied to the facility as a whole, or may be concentrated on specific pieces of process equipment or piping systems.

2.8.1.1

Energy Management Opportunities can be divided into three categories.

WALK THROUGH AUDIT

.

The initial action is a Walk Through Audit, which is a tour through the facility looking for obvious signs of energy waste. The walk through audit is generally more meaningful if it is conducted by an individual who, though not associated with the facility operation, is familiar with both the subject of process insulation and the concept of energy management.

.

Typical items which could be noticed during a walk through audit would include missing or damaged insulation, hot or cold surfaces, wet insulation, deteriorating insulating coverings or protective finishes, missing or damaged vapour retarders, gaps in insulation at expansion/contraction joints, excessive heat radiating from insulated surfaces and other similar items.

2.8.1.2

ENERGY MANAGEMENT OPPORTUNITIES

.

Housekeeping, refers to an energy management action that is repeated on a regular basis and never less than once a year. Examples include repairing damaged insulation coverings, finishes and insulation. Low Cost, refers to an energy management action that is done once, and for which the cost is not considered great. Examples of low cost items could be the insulation of valves and fittings and the replacement of coverings and finishes. Retrofit, refer to an energy management action that is done once, and for which the cost is significant. Examples of retrofit items could be the insulation of piping, ductwork, vessels, tanks, and equipment, upgrading insulation to the recommended thickness, and upgrading protective coverings on outdoor tanks and vessels.

It must be noted that the Rand division between low cost and retrofit is normally a function of the size, type and financial policy of the organisation.

DIAGNOSTIC AUDIT

Once items have been identified in the walk through audit, a diagnostic audit is required to determine the existing energy loss, the reduction in energy loss which would result if new or additional insulation or covering were installed and the

Energy management is dealt with in more detail in Section 4.

12

3 MATERIALS SYSTEMS

3.1 INSULATION FORMS AND MATERIALS

material, or combined with a binder and fibres to make a rigid insulation. Insulation is produced in a variety of forms suitable for specific functions and applications. The combined form and type of insulation determines the proper method of insulation. The forms most widely used follow,

3.1.1 TYPES AND FORMS OF INSULATION Insulation materials are addressed in the following text according to their generic types and forms. Type indicates composition and internal structure, while form implies overall shape or application.

.

Types are normally subdivided into the following three groups. .

.

.

Fibrous Insulation ± is composed of small diameter fibres, which finely divide the air space. The fibres may be parallel or perpendicular to the surface being insulated and they may be separated or bonded together. Glass, rock wool, slag wool and alumina silica fibres are used. Glass fibre and mineral wool (rock and slag) are the most widely used insulation of this type. Cellular Insulation ± is composed of small individual cells separated from each other. The cellular material may be glass or foamed plastic such as polystyrene (closed cell), polyurethane and elastomeric. Granular Insulation ± is composed of small nodules, which contain voids or hollow spaces. It is not considered a true cellular material since gas can be transferred between the individual spaces. This type may be produced as a loose pourable

.

.

.

3.1.2

Rigid boards, blocks, sheets and preformed shapes (i.e. pipe covering, curved segments, lagging). Cellular and granular insulation are produced in these forms. Flexible sheets and pre-formed shapes. Cellular and fibrous insulation are produced in these forms. Flexible blankets. Fibrous insulation is produced in flexible blankets. Cements (insulating and finishing). Produced from fibrous and granular insulation and cement.

MAJOR INSULATION MATERIALS

The following is a general inventory of the characteristics and properties of major insulation materials used in Industrial, Commercial and Institutional installations. .

13

Calcium Silicate is a granular insulation made of lime and silica reinforced with organic arid inorganic fibres and moulded into rigid forms. The temperature range covered is from 38oC (100oF) to 982oC (1800oF). Flexural strength is good. Cal-

.

.

.

.

cium Silicate is water absorbent, however, it can be dried out without deterioration. The material is non-combustible and used primarily on hot piping and surfaces. Jacketing is generally field applied. Cellular Elastomeric insulation is composed principally of natural or synthetic elastomers, or both, processed to form a flexible, semi-rigid or rigid foam with a predominantly closed-cell structure. Upper temperature limit is 104oC (221oF). Cellular Glass is fabricated into boards, pipe covering and other shapes. Service temperatures range from -40oC (-40oF) to 482oC (900oF). This material has a low thermal conductivity at low temperatures, low abrasion resistance, good resistance to substrate corrosion, and good sound absorption characteristics in fibre and cellular form. Fibrous Glass products are manufactured in a variety of forms including flexible blankets, rigid and semi-rigid boards and pipe coverings. Service temperatures range from -73oC (~110oF) to 538oC (1000oF) depending on structure and binder. Glass fibres are bonded together with heat resisting binders. Conductivity of fibrous glass products is low. Cutting characteristics are good. The resilience of glass fibre is high while the impact resistance is low. Installation costs are low. There are good sound absorption characteristics with glass fibre insulation. Foamed Plastic insulation is predominantly closed cellular rigid materials. Thermal conductivity may deteriorate (i.e. increase) with time due to ageing because of air diffusing into the cells. Foamed plastics are lightweight with excellent cutting characteristics. The materials themselves are combustible, but can be produced selfextinguishing. They are available in pre-

.

.

.

formed shapes and boards. Foamed plastics are generally used in lower and intermediate temperature ranges. Insulating and Finishing Cements are a mixture of various insulating fibres and binders with water and cement, to form a soft plastic mass for application on irregular surfaces. Installation costs are high, and insulation values are only fair. Cements may be applied to high temperature surfaces. Finishing cements are one-coat cements used in the lower to intermediate temperature range. Mineral Fibre or Mineral Wool is produced by bonding rock and slag fibres together with a heat resistant binder. The upper service temperature limit can reach 982oC (1800oF). The material is noncombustible. Mineral fibre is available in both rigid pre-formed shapes for piping and vessels, and as a flexible blanket. It is used in high and intermediate temperature ranges. Refractory Fibre Insulation is mineral or ceramic fibres, including alumina and silica, bound with extremely high temperature binders. They are manufactured in blanket or rigid brick form. Thermal shock resistance and temperature limits are high. The material is non-combustible.

Common insulation materials are summarised in Table 6.

3.2

INSULATION SYSTEMS

As an owner contemplating the insulation of equipment or mechanical systems, it is helpful to think of an insulation system as having the following three components. . .

14

Insulating material. Protective covering or finish.

.

Accessories to secure, fasten. Stiffen, support, seal or caulk the insulation and its protective covering or finish.

characteristics of each type. Vapour retarders are available in three forms. .

These components must be compatible for the insulation system to function properly. .

3.2.1

PROTECTIVE COVERINGS AND FINISHES

As indicated in the section titled `Fundamentals', the efficiency and service of insulation is directly dependent upon its protection from moisture entry and mechanical or chemical damage. Choices of jacketing and finish materials are based upon the mechanical, chemical, thermal and moisture conditions of the installation, as well as cost and appearance.

.

3.2.1.3

Protective coverings are divided into six functional types.

3.2.1.1

WEATHER BARRIERS

3.2.1.4

LOW FLAME SPREAD AND CORROSION RESISTANT COVERINGS

When selecting material for potential fire hazard areas, the insulation material and the jacketing must be considered as a composite unit. Most of the available types of jacketing and mastic have low (less than 25) flame spread rating. This information can usually be obtained from manufacturer's data.

VAPOUR RETARDERS

Vapour retarders are designed to retard the passage of moisture vapour from the atmosphere to the surface of the insulation (Table 1). Joints and overlaps must be sealed with a vapour tight adhesive or sealer. Refer to Table 8 for detailed information on types of vapour retarders plus

MECHANICAL ABUSE COVERINGS

Metal jacketing provides the strongest protection against mechanical damage from personnel, equipment, and machinery. The compressive strength of the insulation material should also be considered when assessing mechanical protection.

The basic function of the weather barrier is to prevent the entry of water. If water is deposited within the insulation, its insulation properties will be significantly reduced. Applications consist of either a jacket of metal or plastic, or a coating of weather barrier mastic (Table 7). Jacketing must be overlapped sufficiently to repel water. The use of plastic jacketing materials with low resistance to ultraviolet rays should be avoided unless protective measures are taken.

3.2.1.2

Rigid jacketing ± reinforced plastic, aluminium or stainless steel fabricated to the exact dimensions and sealed vapour tight. Membrane jacketing ± metal foils, laminated foils and treated or coated papers, which are generally factory, applied to the insulation material. Additional sealing beyond the factory seal may be necessary depending on the installation temperature and humidity conditions. Mastic applications ± either emulsion or solvent types which provide a seamless coating but require time to dry.

Resistance to corrosion varies among the plastic and metal jacketing materials. Of the metal jackets, stainless steel is the most successful in resisting corrosive atmospheres, spills or leaks. Mastics are also generally resistant to corrosive atmospheres.

15

3.2.1.5

APPEARANCE COVERINGS AND FINISHES

insulation), or if a significant amount of vibration must be considered.

Various coatings, finishing cements, fitting covers and jackets are chosen primarily for their appearance value in exposed areas. Typically for piping, jacketed insulation is covered with a reinforcing canvas and coated with mastic to give a smooth even finish. When dry it can be painted or left as is to give a white colour.

3.2.1.6

3.2.2.3

The covering must be suitable for the operating temperature of the insulation surface.

3.2.2.4

3.2.3

PROPERTIES OF PROTECTIVE COVERINGS

Certain properties of jacketing and mastic materials that must he considered to meet the previously listed functions follow.

.

.

COMPATIBILITY .

Coverings must be compatible with the insulation material over which they are applied, as well as with elements in the environment such as industrial chemicals, salt air and ultraviolet or infrared light.

3.2.2.2

ACCESSORIES

The term accessories is applied to devices or materials serving one or more of the following functions. .

3.2.2.1

VAPOUR PERMEABILITY

Coverings should have low vapour permeability on low temperature installations to prevent, or at least retard the passage of moisture vapour into the insulation. For high temperature applications a vapour permeable covering should be used to allow moisture to pass outwards.

HYGIENIC COVERINGS

Coatings and jackets must present a smooth surface, which resists fungal or bacterial growth, especially in food processing areas. High temperature steam or high-pressure water wash down conditions require jackets with high mechanical strength and temperature ratings (plastics or metals are typically used).

3.2.2

TEMPERATURE RANGE

. . .

Securement of the insulation and/or jacketing. Insulation reinforcement for cement or mastic applications. Stiffening around structures which may not support the weight of high-density insulation. Supports (pipe, vessel and insulation). Sealing and caulking. Water flashing. Compensation for expansion/contraction of piping and vessels.

Improper application of any of these accessories could be a significant factor in the failure of insulation systems.

RESISTANCE TO INTERNAL AND EXTERNAL MOVEMENT

The ability of a covering to resist movement is an important element to consider if there will be thermal expansion and contraction of the insulation it covers (i.e. shrinkage of high temperature

3.2.4

16

SECUREMENTS

Insulation is not a structural material and must be supported, secured, fastened or banded in place.

3.2.8

Securements must be compatible with insulation and jacketing materials. Possible choices are listed below. . . . . . .

Insulation at points of support is necessary to minimise heat loss. Accessories, which may be used at points of support, are as follows. . High-density insulation inserts to protect insulation at points of support. Pipe support saddles and shoes. . Metal shields used to protect insulation. . Wood blocks or dowels for load bearing.

Welded studs and pins. Staples. Clips. Wire and metal straps. Self-adhering laps on outer jackets. Adhesives.

Ambient temperature and humidity conditions affect the effectiveness of tapes and adhesives on certain installations. Check the temperature range and vapour permeability properties before choosing adhesives.

3.2.5

3.2.9

. . . .

INSULATION REINFORCEMENT FOR CEMENT AND MASTICS

3.2.10

Canvas. Glass fibre fabric. Expanded metal lath. Metal mesh. Wire netting (chicken wire).

WATER FLASHING

3.3 COMMON APPLICATIONS

Flashing directs the flow of water away from the insulation and may be constructed of metal or plastic.

3.2.7

The following section deals with typical application methods experienced in the insulation industry. They should not be considered as the only methods of applying insulation and its installation. For example, different thickness and different insulation may require radically different attach-

STIFFENING

Metal lath and wire netting can be applied on high temperature surfaces before insulation is applied.

EXPANSION AND CONTRACTION COMPENSATION

Accessories used in the design of expansion and contraction joints, include the following: . Manufactured overlapping or slip joints. . Bedding compounds and flexible sealers.

Compatibility of materials must be considered to prevent corrosion.

3.2.6

SEALING AND CAULKING

A variety of sealers, caulking and tapes are available for sealing vapour and weather barrier jackets, joints and protrusions. These products are manufactured in a large range of temperature and vapour permeability properties. Some are designed specifically for use with one type of insulation or manufacturer's product.

Whether factory or field applied, mechanical strength can be added to insulation through the application of any of the following items. .

SUPPORTS

17

ment methods because of weight. Also, system temperature plays a big part in deciding which application method is most suitable. Insulation contractors or manufacturers are usually willing to recommend the most appropriate application method.

method of application may be used where available insulation thickness is less than that required, or for retrofitting applications. Care should be taken with pipe insulation to ensure that dimensional measures coincide with standard industry practice to provide a proper fit for multiple layer construction.

Pipe covering is generally the dominant part of a mechanical insulation system. This section describes a number of different pipe insulation installation methods. Typical duct, vessel and tank insulation systems are also shown.

3.3.1

3.3.2

PIPE INSULATION FOR INTERIOR APPLICATIONS

A jacketing material is generally applied to mineral fibre pipe insulation for the purpose of protection or to act as a vapour retarder. The application is suitable for hot or cold temperature conditions. The type of jacketing used depends on the end use conditions (Figure 6). Generally the jacket is a laminate of kraft and foil with glass fibre scrim reinforcement. Other materials may be used in cases where greater protection or a different finish is required.

MULTIPLE LAYER CONSTRUCTION

Multiple layer construction is the use of more than one layer of insulation rather than a single layer of equivalent thickness. This application method provides compensation for expansion and contraction where pipe or equipment temperatures are high. Staggering of joints in multiple layer construction reduces heat loss at the joints thus creating a more thermally efficient installation. This

The jacketed product may be left exposed or finished with a canvas and lagging material to provide a smooth, neat and long lasting finish.

1. Pipe. 2. Insulation. 3. Longitudinal lap on factory-applied jacket (selfadhesive or secured with adhesive). 4. Longitudinal lap on factory-applied jacket secured with staples (staples are coated with super-barrier mastic on cold applications). 5. Circumferential butt strip. Self adhering or field adhering. 6. Longitudinal lap on field-applied jacketing is adhered with appropriate adhesive or sealer. 7. Butt joint overlap sealed (tape at overlap joints is optional on cold applications). 8. Wire, tapes or hands securing insulation in place before the jacket is applied.

Figure 6: Field and Factory-Applied Non-Metal Jacketing

18

3.3.3

METAL JACKETING

Metal jacketing is generally used to protect insulation from physical damage (Figure 7). It is particularly useful for outdoor applications. The jacketing material may also be chosen to resist chemical attack. For example, a highly corrosive atmosphere may require the application of a stainless steel jacketing system instead of the standard aluminium material.

3.3.4

FLEXIBLE ELASTOMERIC PIPE COVERING

Flexible elastomeric pipe covering is used on cold temperature piping such as air-conditioning systems (Figure 8). It is generally manufactured as a continuous tube, which can be pushed over small diameter piping during installation. Slitting before installing is another option. Joints are sealed with contact adhesive.

3.3.5

1. 2. 3. 4.

Pipe Insulation. Wire, tape or bands securing insulation in place. Overlaps positioned to shed water (butt joint overlaps should be wide enough to provide weatherproofing). 5. Rivets or screw at longitudinal laps for securement. 6. Metal bands at butt joint overlaps, and spaced between butt joints for jacket securement.

Figure 7: Field Applied Metal Jacketing (Source: Canadian Govn Pub)

FITTINGS INSULATION

Insulation of fittings on a job is an extremely important part of the overall system (Figure 9). The insulation of elbows is usually accomplished by using mitred pipe insulation. Generally the same material and size of insulation is used to make the elbow insulation. Where a Victaulic type pipe fitting is used insulation is either built up to a greater thickness than the surrounding line pipe insulation, or standard pipe covering is grooved out to fit around the coupling. In some cases, pre-formed fitting insulation is available to simplify the installation. The insulated fitting is then covered with cloth or canvas and lagging material for protection and a neat finish.

3.3.6

1. Pipe or tubing. 2. Insulation (to facilitate sweating of joints, insulation can be pulled back temporarily on either side of the connection then released to extend over the joint before sealing.) 3. Contact adhesive is applied to both surfaces of longitudinal and butt joints.

PVC OR GLASS FIBRE FITTING INSULATION

PVC fitting covers are generally used for hot or cold commercial applications where a neat finish is

19

Figure 8: Flexible Elastomeric Pipe Covering (Source: Canadian Govn Pub)

1. Pipe. 2. Pipe insulation (shown in A) with factory applied non-metal jacketing (metal jacketing shown in B). Jacketing extends under the fitting insulation and finish. 3. Mitered segments of pipe covering, cut to form a tight fit (adhesive between miters on pre-fabricated applications or when required.) 4. Glass fiber fill insulation (optional ± used as a means of support when the mitered elbow has not been prefabricated into two self supporting halves.) 5. Wire or banding (unnecessary when prefabricated.) 6. Pre-formed metal elbow cover secured with sheet metal screws. 7. Finishing cement applied to smooth surface. 8. Fabric applied with adhesive on the surface of finishing or insulating cement.

Figure 9: Mitred Insulation Elbow Oversized Application

sufficient and a final finishing method (i.e. canvas) is not required (Figure 10). These fittings are easy to install and come in different colours (white being

(Source: Canadian Govn Pub)

the most common) with either a dull or shiny appearance. PVC jacketing may also be used to protect piping insulation.

1. 2. 3. 4. 5. 6. 7.

Pipe. Pipe insulation (shown with factory-applied jacket). Collar of oversized pipe insulation. Glass fiber insert wrapped around the elbow. PVC fitting cover. Reducing end cap. Vapor retarder adhesive on all joints and overlaps (cold applications only.) 8. Vapor retarder tape.

Figure 10: PVC/Glass Fibre Elbow Insulation System

20

(Source: Canadian Govn Pub)

3.3.7

INSULATION OF IN-LINE FLANGES OR COUPLINGS

In-line flanges or couplings, are difficult to insulate with standard sized products. In these cases blanket wrap insulation is used to surround the coupling and is finished with both canvas and lagging, or a PVC fitting cover (Figure 11).

3.3.8

REMOVABLE AND REUSABLE INSULATION 1. 2. 3. 4. 5.

Removable insulation may be used where valves require constant maintenance. These are made of a fabric cover with a contained insulation, and a fastening system such as the one shown (Figure 12).

3.3.9

Pipe. Pipe insulation (factory applied jacket). Vapor retarder tape along longitudinal seam and around ends. Glass fiber insert wrapped around the coupling. PVC cover extending over the pipe insulation.

Figure 11: PVC/Glass Fibre Coupling or In-Line Flange Insulation System

DUCT INSULATION

Ducts can be insulated with either a flexible blanket type product or with a rigid board system (Figure 13). The rigid board system offers superior abuse resistance, but may be more difficult to apply because of the necessity of cutting and fitting around connections and changes in direction. Where a vapour retarder system is required for cold or dual temperature ducting, care should be taken to seal all joints with adhesive to maintain the vapour retarder. Any punctures of the vapour retarder facing should be vapour-sealed. Rigid board insulation with factory applied jacketing should have joints and edges sealed with an adhesive backed vapour retarder tape. Blanket wrap insulation may be available with a lap joint, which can be sealed with a vapour retarder adhesive.

1. 2. 3. 4. 5. 6. 7.

21

Valve. Removable cover. machine stitching. Metal stitching at edges. Quilting washer. Lacing hooks and wire. Adjacent insulation.

Figure 12: Removable and Reusable Insulation

1. 2. 3. 4.

Rectangular duct. Blanket insulation (shown with factory-applied vapor retarder jacket). Factory lap (sealed with adhesive and/or staples or vapor retarder tape). Vapor retarder tape over tears and penetrations of the vapor retarder jacket (optional in hot applications.) 5. Mechanical fasteners supporting insulation n the underside of ducts ovedr 24" wide (spaced 3" from the butt joint.)

1. 2. 3. 4. 5.

Figure 13: Flexible Fibrous Blanket Duct Insulation Rectangular/Indoors (Source: Canadian Govn Pub)

3.3.10

Housing or shaft. Liner or fibrous board insulation. Adhesive. Mechanical fasteners. Joint sealer.

Figure 14: Field Applied Lining Ducts, Plenums and Housings

FIELD APPLIED LINING

When field applied (applied on site rather than in the factory where the components were made) to the inside surface of housings or shafts, insulation is attached by means of adhesives and mechanical fasteners, depending on the size of the housing and the velocity of the air moving through it (Figure 14). Transverse joints and exposed edges are taped or coated with sealer to hold the insulation firmly in place.

3.3.11

INSULATION OF TANKS AND VESSELS

1. Vessel wall. 2. Insulation board, scored or beveled to fit the curvature of the vessel surface. 3. Stainless steel bands and "S" clips as required (see inset). An alternate method of securement is impalement of insulation on mechanical fasteners. 4. Bottom tier of insulation is cellular glass in areas where water absorption and wicking may occur (optional). 5. Corrugated or smooth sheet metal sheathing. 6. Head flashing. 7. Caulking/flashing at fittings.

The choice of application method depends on the conditions of the system. If welding pins onto an existing tank or vessel (Figure 15) is dangerous then the insulation can be secured by banding in place. Either flexible batt or rigid board insulation may be used to insulate tanks or vessels. The insulation

22

Figure 15: Curved Surfaces Rigid Board Insulation (Source: Canadian Govn Pub)

1. 2. 3. 4. 5. 6.

Head insulation (rigid block is shown). Floating ring of cable. Head bands on 12" centers. Shell insulation. Head insulation supporting ring (not required for horizontal vessels). 1" joint between support ring and shell insulation packed with mineral or glass fibre insulation. 7. Segments of flat sheet metal cut in wedge shapes, to overlap and conform to the surface of the head insulation. 8. Band at base of head insulation cover. 9. Sheet metal screws on 3" centres along horizontal and vertical seams. 10. High density insulation for walkway. 11. Roofing materials or reinforced mastic. 12. Caulking and flashing as required. 13. Banding to secure rim angle. 14. Metal I-beams used to stiffen head structure.

Figure 16: Metal Head Insulation, Securement and Cover Fabrication (Source: Canadian Govn Pub)

3.3.12

manufacturer may recommend choice of type of product. Rigid insulation such as calcium silicate will have to be scored to conform to the curvature of the tank. Mineral fibre insulation may be bent to conform to the vessel shape.

VESSEL AND TANK HEAD INSULATION

Vessel tops are a major source of heat loss. Thus, the insulation of the tops of tanks and vessels (Figure 16) is important to maintain temperature within the process. Proper protection of the insulation on the top of the tank or vessel is critical to prevent heat loss in the system.

Where the tank or vessel comes in contact with the ground, an insulation material that does not wick or absorb moisture should be used around the base of the tank. Cellular glass is typically used.

In addition to the insulation method shown, roofing contractors normally insulate flat tank surfaces. The nature of the insulation system is critical and should be performed by qualified insulation contractors only.

Weather protection of insulated outdoor tanks and vessels is a key requirement. Sheet steel or aluminium panels are fastened together with vertical and horizontal laps sufficient to shed rain water to protect the insulation.

23

4 ENERGY MANAGEMENT OPPORTUNITIES

4.1.1

Energy Management Opportunities is a term that represents the ways that energy can be used wisely to save money. A number of typical Energy Management Opportunities subdivided into Housekeeping, Low Cost, and Retrofit categories are outlined in this section with worked examples to illustrate the potential energy savings. This is not a complete listing of the opportunities available for insulation. However, it is intended to provide ideas for management, operating and maintenance personnel to allow them to identify other opportunities that are applicable to a particular facility. Appropriate modules in this series should be considered for Energy Management Opportunities existing within other types of equipment and systems.

4.1.1.1

HOUSEKEEPING WORKED EXAMPLES REPAIR DAMAGED INSULATION

During a walk through audit of a process facility it was noted that the insulation on an NPS 4 pipeline had been damaged and removed for a ten-metre length. This pipeline was carrying high temperature process fluid at 121oC and the ambient temperature was 18oC. The original insulation was 76 mm thick mineral fibre. A diagnostic audit was performed to establish the heat loss from this section of pipe before and after the damaged insulation had been removed to establish the additional energy loss without insulation.

The following text briefly highlights several Energy Management Opportunities and is followed by worked examples or explanatory text for illustrative purposes.

From Table 1 the heat loss from NPS 4 pipe at 121oC is approximately 530 Wh/m. From Table 3 the heat loss for the same piping with 76 mm of mineral fibre insulation is 28 Wh/m.

4.1 HOUSEKEEPING OPPORTUNITIES

For a ten-metre length, the reduction in heat loss is now calculated.

Implemented housekeeping opportunities are energy management actions that are done on a regular basis and never less than once a year. The following are typical Energy Management Opportunities in this category include: 1. Repair damaged insulation. 2. Repair damaged coverings and finishes. 3. Maintain safety requirements.

Heat loss reduction per hour ˆ 10  (530 ± 28) ˆ 10  502 ˆ 5020 Wh/h If the pipe in question is in operation 8760 hours per year the annual heat loss reduction can be calculated.

24

Annual heat loss reduction ˆ Hourly heat loss reduction  operating hours per year

4.1.1.2

ˆ 5020  8760

Damage to the insulation cover and finish can expose the insulation and leave it susceptible to damage by water, sunlight and mechanical abuse. Damage will reduce the effectiveness of insulation and thus will increase the heat loss and its associated cost.

ˆ 43 975 200 Wh/yr or 43 975.2 kWh/yr. If the process fluid is heated by electricity which costs R0.20/kwh, the reduction in heat loss can be equated to a Rand savings as follows.

4.1.1.3

Annual Rand savings ˆ Annual reduction in heat loss  energy unit cost ˆ

REPAIR DAMAGED INSULATION COVERS AND FINISHES

MAINTAIN SAFETY REQUIREMENTS

Pipes that are exposed to human contact should be insulated such that the temperature of the exposed surface does not exceed 70oC. Major burn hazards exist at temperatures above this. A review of Table 3 shows that the insulation surface temperatures never approach this figure.

43 975 200 kWh=yr  RO:20=kWh 1000

ˆ R8795.04/yr The estimated cost to supply and install 10 metres of 76mm glass fibre insulation was R4000.

4.2

R4000:00 Simple payback ˆ R8795:04 ˆ 0.45 years (5 months)

LOW COST OPPORTUNITIES

Implemented low cost opportunities are energy management actions that are done once and for which the cost is not considered great. The following are typical Energy Management Opportunities in this category include:

A further benefit of the insulation is the removal of a potential employee burn hazard. Without insulation, the pipe surface temperature would be approximately 121oC. By adding the insulation the outer surface of the insulation would be 23oC.

1. Insulate non-insulated pipe. 2. Insulate non-insulated vessels. 3. Add insulation to reach recommended thickness.

This is a housekeeping item even though there is a cost involved for the replacement of the 10 metres of insulation because it is considered as a part of the normal housekeeping / maintenance program in any facility.

4.2.1

To assist in performing the calculation Worksheet 1-2 has been developed and is completed for this specific example.

4.2.1.1

25

LOW COST WORKED EXAMPLES INSULATE NON-INSULATED PIPING

During a walk through audit of a facility it was noted that an NPS 2 branch steam main 20 metres

long feeding a new unit heater had not been insulated during the original installation. The steam temperature was 121oC. It was decided to investigate the potential energy and dollar savings if this main was insulated with the recommended thickness of cellular glass insulation. The main was in operation 2880 hours per year.

insulated with the recommended insulation thickness of mineral fibre insulation.

From Table 3 it was established that the recommended thickness of cellular glass insulation for this application was 64 mm, and the heat loss if this amount of insulation were installed would be 35 Wh/m From Table 1 the heat loss from this same pipe with no insulation is 290 Wh/m.

ˆ 10m2

Vessel surface area ˆ ATop ‡ ASide ‡ ABottom ˆ (2  1) ‡ [(2  1) ‡ (2  1) ‡ (1  1) ‡ (1  1)] ‡ (2  1) ˆ 2‡6‡2

From Table 3 the recommended insulation thickness for a flat surface at 177oC is 102 mm, and its heat loss is 63 Wh/m2. Worksheet 1-3 is used to calculate the annual loss due to the addition of insulation as 551 880 kWh/yr.

Using Worksheet 1-2 the annual reduction in heat loss due to the addition of insulation would be 14 688 00 Wh/yr or 14 688/yr or 52 876.8 MJ/yr.

On the basis that the vessel is heated with electric immersion heaters, and the energy cost for electricity is R0.20/kWh, the annual potential Rand savings may be calculated.

Steam was produced in a boiler operating at 75 per cent efficiency using Sasol gas at R53.00/GJ. Rand savings ˆ

Annual savings ˆ 551 880  R0.20

52 876:8  53:00 1000  0:75

ˆ R110 376

ˆ R3736.62/yr

Estimated cost to supply and install 100 mm of mineral fibre insulation on the top, side and bottom of the tank is R30 000.

Estimated cost to supply and install the insulation is R3000. Simple payback ˆ

R3 000:00 R3 736:62

Simple payback ˆ

ˆ 0.80 years (10 months)

R30 000 R110 376

ˆ 0.27 years (3 months)

4.2.1.2

INSULATE NON-INSULATED VESSELS

4.2.1.3

During a walk through audit of a facility it was noted that a rectangular tank 2m long by 1 m wide by 1 m deep, with a hinged lid was not insulated even though the tank was maintained at 177oC for 8760 hours per year. A diagnostic audit was performed to establish the potential energy and cost savings if the vessel was

26

ADD INSULATION TO REACH RECOMMENDED THICKNESS

During a walk through audit of a facility, it was noted that a two-metre diameter vessel, with a surface area of 25 m2 containing a liquid being maintained at 65oC was insulated with 25 mm of mineral fibre insulation. The vessel was in operation 8400 hours per year and was heated with electricity at the cost of R0.20/kWh

Using Table 3 the recommended insulation thickness for this application was 51 mm with an associated heat loss of 32 Wh/m2. A diagnostic audit was performed to establish the energy and cost savings if the insulation was increased in thickness to the recommended 51 mm.

4.3 RETROFIT OPPORTUNITIES Implemented retrofit opportunities are energy management actions, which are done once and for which the cost is significant. Many of the opportunities in this category will require detailed analysis by specialists, and cannot be covered in this module. The following are typical Energy Management Opportunities in the retrofit category:

Manufacturer's data for 25 mm of mineral fibre insulation under these conditions indicated the heat loss was 105 Wh/m2 of surface area of the tank.

1. Upgrade existing insulation levels. 2. Review economic thickness requirement. 3. Limited budget upgrade.

Worksheet 1-3 is used twice. The first time to calculate the reduction in heat loss from a bare vessel to 25 mm of insulation and the second time to calculate the reduction in heat loss between the bare vessel and 51 mm of insulation.

4.3.1

The energy savings in adding 26 mm of insulation and increasing the overall thickness to 51 mm can be calculated.

4.3.1.1

Energy Savings

81 900 000 ± 61 950 000

ˆ

19 950 000 Wh/yr

or

19 950 kWh/yr

A review of Table 3 indicated that the heat loss for this main based on the cellular glass insulation was 145 Wh/m. It was further noted that if the insulation was changed to mineral fibre, the heat loss would be reduced to 99 Wh/m. It should be noted that the insulation thickness remained the same.

Rand savings ˆ 19 950  R0.20 ˆ R3 990 Estimated cost to supply and install the additional insulation is R30 000. Simple payback ˆ

UPGRADE EXISTING INSULATION LEVELS

During a walk through audit it was noted that an NPS 6, steam header operating at 288oC for 8760 hours per year was insulated with cellular glass insulation. The steam header was 100 metres long.

ˆ Savings with 51 mm ± Savings with 25 mm ˆ

RETROFIT WORKED EXAMPLES

Annual energy savings of mineral fibre insulation can be calculated.

R30 000 R3 990

ˆ 7.5 years

Annual energy savings ˆ (Cellular glass loss ± mineral fibre loss)  Length  operating hours per year

27

ˆ (147 ± 100)  100  8760 ˆ 41 172 000 Wh/yr or ˆ 41 172 000  3.6 ˆ 148 219 200 kJ/yr or ˆ 148 219.2 MJ/yr

numerous steam branch mains were not insulated. These steam mains varied in size from NPS 1 to NPS 6. It was estimated that the equivalent length would be equal to 350 m of NPS 4. The temperature of the steam was 121oC and the mains were in operation for an estimated 4400 hours per year. The steam was produced in a lowpressure boiler, which used synthetic gas as the fuel and operated at 77 per cent efficiency. The cost of gas at the facility was R58.00/GJ.

The steam was produced in a boiler operating at 76 per cent efficiency using synthetic at a cost of R58.00/GJ. Rand savings ˆ

148 219:2  R58:00 1000  0:76

A review of Table 3 indicated that the recommended mineral fibre insulation thickness for NPS 4 pipe at 121oC would be 76 mm. and that the heat loss would be 28 Wh/m. Table 1 indicates that the heat loss for bare steel pipe at 121oC is 530Wh/m.

ˆ R11 311.50/yr The estimated cost to replace the cellular glass insulation with glass fibre insulation was R100 000. Simple payback ˆ

R100 000 R11 311:50

ˆ 8.8 years

Using Worksheet 1-2 it was established that the reduction in heat loss if the bare pipe were insulated to the recommended thickness with glass fibre insulation would be or 2 783 088 MJ/yr.

In this case the replacement is not justified based on the payback. However, if the original insulation had been less than the recommended thickness, the heat loss and therefore the savings would have been much greater. This would have to be calculated using insulation manufacturers published data.

4.3.1.2

Dollar savings ˆ

2 783 088  R58:00 1000  0:77

ˆ R209 635/yr The cost to supply and install the 76mm insulation on the uninsulated piping was R80 000

REVIEW ECONOMIC INSULATION THICKNESS

Simple payback ˆ

R80 000 R209 635

ˆ 0.38 years (5 months) As indicated in the `Fundamentals' section of this module, in some instances, the economic insulation thickness should be considered and compared to recommended insulation thickness to establish potential savings.

4.3.1.3

However, due to certain financial constraints, management was not prepared to invest this amount of money at this time. Because of the budget limitations imposed by management, a new set of calculations was performed on the basis of using 25 mm of mineral fibre insulation. The insulation manufacturer indicated that under these conditions the heat loss would be 200 Wh/m for every hour of operation.

LIMITED BUDGET UPGRADE

During a walk through audit of a facility, which was being considered for purchase, it was noted that

28

Using Worksheet 1-2 again the reduction in heat loss if 25 mm of mineral fibre insulation is used is 1 829 520 MJ/yr Rand savings ˆ

Even though the simple payback was not as good as with the 25 mm as with the 76 mm of insulation, management was prepared to invest R70 000 for this limited budget upgrade.

1 829 520  R58:00 1 000  0:77

ˆ R137 808/yr Estimated cost to supply and install the insulation is R70 000 Simple payback ˆ

R70 000 R137 808

ˆ 0.51 year (6 months).

29

APPENDICES

WORKSHEETS WORKSHEET 1-1 Insulation Material Properties Selection Considerations

Company: _______________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________ Date: ________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________ Location: ________________________________________________________________________________________________________________________________________________ By: ___________________________________________________________________________________________________________________________________________________________________ Insulation for: ____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________ Important

Property APPEARANCE (is insulation exposed?) CHEMICAL NEUTRALITY (is insulation subject to intermittent wetting?) BREAKING LOAD (Must insulation bridge discontinuities in its support?) CAPILLARITY (is insulation in a wet area?) COEFFICIENT OF EXPANSION AND CONTRACTION (is insulation layered or are expansion joints required?) COMBUSTIBILITY (is there a fire hazard in the area?) COMPRESSIVE STRENGTH (must insulation support a load or be subject to mechanical abuse?) DENSITY SHRINKAGE (is this a high temperature application?) RESISTANCE TO ULTRAVIOLET RADIATION (is insulation exposed to sunlight?) RESISTANCE TO BACTERIAL OR FUNGAL GROWTH (is insulation used in a food or cosmetic preparation area?)

30

Not Important

WORKSHEET 1-2 Heat Loss From Piping Company: ______________________________________________________________________________________________________________________________

Date: ___________________________________________________________________________________________________________________________________________________

Location: __________________________________________________________________________________________________________________________________

By: _______________________________________________________________________________________________________________________________________________________

Pipe diameter (NPS) _________________________________________________________________________________________

Pipe Length ________________________________________________________________________________________________________________ m

Pipe temperature _________________________________________________________________________________________ oC

Operating Hours per year ______________________________________________________________________________________________________ h

Proposed insulation type _______________________________________________________________________________________________________________

Proposed Insulation thickness _________________________________________________________________________________ mm

Uninsulated

Insulated

Heat loss Per metre _________________________________________________________________Wh/m.h (Table 1)

______________________________________________________________________________________________________Wh/m.h (Table 3)

Heat loss/h ˆ Heat loss/m.h  length

Heat loss/m.h  length

___________________________________________________________________________  _____________________________________________________

_____________________________________________________________________________ _______________________________________________________

_________________________________________________________________________________________________________________________________________________Wh/h

_________________________________________________________________________________________________________________________________________________Wh/h

Annual heat loss ˆ Heat loss  h/yr

Heat loss/h  h/yr

___________________________________________________________________________  _____________________________________________________

_____________________________________________________________________________ __________________________________________________________________________

____________________________________________________________________________________________________________________________________Wh/h (1)

__________________________________________________________________________________________________________________________________Wh/yr (2)

Reduction in heat loss due to addition of insulation

ˆ

(1) ± (2)

ˆ ________________________________________________________________________________________________ ± ____________________________________________ ˆ _____________________________________________________________________________________________________________________________________Wh/yr or ______________________________________________________________________________________Wh/yr  3.6 kJ/Wh ˆ _____________________________________________________________________________________________________________________________________________kJ/yr Annual Rand savings may now be calculated using cost per unit of heating medium. Ensure that units are compatible.

31

WORKSHEET 1-2 Heat Loss From Piping Company: _____________________________________________ABC _________________Co. ________________________________________________________________

Date: ___________________________________________________________________________________________________________________________________________________

Location: ________________________________________ANYTOWN __________________________________________________________________________________________ Low cost worked example No. 1

By: ______________________________________________________________MBE _________________________________________________________________________________________

Pipe diameter (NPS) ________________________________________________2_________________________________________

Pipe Length _________________________________________________________20 _______________________________________________________ m

Pipe temperature _________________________________________121 ________________________________________________ oC

Operating Hours per year _________________________________________2_______880 ______________________________________________________ h

Proposed insulation type ___________________________________cellular __________________________glass __________________________________________________

Proposed Insulation thickness _________________________________34 ________________________________________________ mm

Uninsulated

Insulated

Heat loss Per metre ________________________________290 _________________________________Wh/m.h (Table 1)

_________________________________________________35 _____________________________________________________Wh/m.h (Table 3)

Heat loss/h ˆ Heat loss/m.h  length

Heat loss/m.h  length

___________________________________290 ________________________________________  __________________________20 ___________________________

___________________________________35 __________________________________________ _________________________20 ______________________________

______________________________________________________________________5_______800 ____________________________________________________________________Wh/h

___________________________________________________________________________700 ______________________________________________________________________Wh/h

Annual heat loss ˆ Heat loss  h/yr

Heat loss/h  h/yr

__________________________________5________800 _________________________________  ________________________2________880 _____________________

_______________________________700 ______________________________________________ ________________2_______880 ___________________________________________________

___________________________________________16 ____________704 ________________000 ___________________________________________________________Wh/yr (1)

_________________________________________________________2_______016 _________________000 _________________________________________________Wh/yr (2)

Reduction in heat loss due to addition of insulation

ˆ

(1) ± (2)

ˆ ______________________________16 ____________704 ________________000 ______________________________________ ± _____2_______016 ________________000 ________________ ˆ _______________________________________________14 ____________688 ________________000 __________________________________________________________Wh/yr or _______________________14 ____________688 ________________000 ___________________________________Wh/yr  3.6 kJ/Wh ˆ __________________________________52 ____________876 ________________800 _______________________________________________________________________________kJ/yr Annual Rand savings may now be calculated using cost per unit of heating medium. Ensure that units are compatible.

32

WORKSHEET 1-2 Heat Loss From Piping Company: _____________________________________________XYZ __________________Co. _______________________________________________________________

Date: ___________________________________________________________________________________________________________________________________________________

Location: ________________________________________ANYTOWN __________________________________________________________________________________________ Housekeeping worked example No. 1

By: ______________________________________________________________MBE _________________________________________________________________________________________

Pipe diameter (NPS) ________________________________________________4_________________________________________

Pipe Length _________________________________________________________10 _______________________________________________________ m

Pipe temperature __________________________________________________________121 _______________________________ oC

Operating Hours per year _________________________________________8_______760 ______________________________________________________ h

Proposed insulation type ___________________________________mineral ____________________________fibre ________________________________________________

Proposed Insulation thickness _________________________________76 ________________________________________________ mm

Uninsulated

Insulated

Heat loss Per metre ________________________________530 _________________________________Wh/m.h (Table 1)

_________________________________________________28 _____________________________________________________Wh/m.h (Table 3)

Heat loss/h ˆ Heat loss/m.h  length

Heat loss/m.h  length

___________________________________530 ________________________________________  __________________________10 ___________________________

____________________________________28 _________________________________________ _________________________10 ______________________________

______________________________________________________________________5_______300 ____________________________________________________________________Wh/h

___________________________________________________________________________280 ______________________________________________________________________Wh/h

Annual heat loss ˆ Heat loss  h/yr

Heat loss/h  h/yr

__________________________________5________300 _________________________________  ________________________8________760 _____________________

_______________________________2800 ______________________________________________ ____________________8_______760 _______________________________________________

___________________________________________46 ____________428 ________________000 _____________________________________________________________Wh/h (1)

_________________________________________________________2________452 ________________800 _________________________________________________Wh/yr (2)

Reduction in heat loss due to addition of insulation

ˆ

(1) ± (2)

ˆ ______________________________46 ____________428 ________________000 ______________________________________ ± _____2_______452 ________________800 ________________ ˆ _______________________________________________43 ____________975 ________________200 __________________________________________________________Wh/yr or ______________________________________________________________________________________Wh/yr  3.6 kJ/Wh ˆ _____________________________________________________________________________________________________________________________________________kJ/yr Annual Rand savings may now be calculated using cost per unit of heating medium. Ensure that units are compatible.

33

WORKSHEET 1-3 Heat Loss From Piping Company: ______________________________________________________________________________________________________________________________

Date: ___________________________________________________________________________________________________________________________________________________

Location: __________________________________________________________________________________________________________________________________

By: _______________________________________________________________________________________________________________________________________________________

Equipment ____________________________________________________________________________________________________________________________

Operating Hours per year ______________________________________________________________________________________________________ h

Surface area __________________________________________________________________________________________________________ m2

Proposed Insulation type __________________________________________________________________________________________________________________________________________________

Product temperature ____________________________________________________________________________ C

Proposed Insulation thickness _________________________________________________________________________________ mm

Uninsulated

Insulated

Heat loss_________________________________________________________________________Wh/m2 (Table 1)

_________________________________________________________________________________________________________Wh/m2 (Table 3)

Total heat loss/h ˆ Surface area  Heat loss

Surface area  Heat loss

___________________________________________________________________________  _____________________________________________________

_____________________________________________________________________________ _______________________________________________________

_________________________________________________________________________________________________________________________________________________Wh/h

_________________________________________________________________________________________________________________________________________________Wh/h

Annual heat loss ˆ Heat loss  h/yr

Heat loss/h  h/yr

___________________________________________________________________________  _____________________________________________________

_____________________________________________________________________________ __________________________________________________________________________

__________________________________________________________________________________________________________________________________Wh/yr (1)

__________________________________________________________________________________________________________________________________Wh/yr (2)

o

Reduction in heat loss due to addition of insulation

ˆ

(1) ± (2)

ˆ ________________________________________________________________________________________________ ± ____________________________________________ ˆ _____________________________________________________________________________________________________________________________________Wh/yr or ______________________________________________________________________________________Wh/yr  3.6 kJ/Wh ˆ _____________________________________________________________________________________________________________________________________________kJ/yr Annual Rand savings may now be calculated using cost per unit of heating medium. Ensure that units are compatible.

34

WORKSHEET 1-3 Heat Loss From Piping Company: _____________________________________________ABC _________________Co. ________________________________________________________________

Date: ___________________________________________________________________________________________________________________________________________________

Location: ________________________________________ANYTOWN __________________________________________________________________________________________

By: ______________________________________________________________MBE _________________________________________________________________________________________

Equipment ______________________________Heating _____________________________tank _________________No. ________________1________________________________

Operating Hours per year _________________________________________8_______760 ______________________________________________________ h

Surface area _________________________________________________10 _________________________________________________________ m2

Proposed Insulation type __________________________________________________________________mineral ____________________________fibre ____________________________________________________

Product temperature __________________________________177 __________________________________________ oC

Proposed Insulation thickness _________________________________102 ________________________________________________ mm

Uninsulated

Insulated

Heat loss_______________________________________2_______800 ___________________________Wh/m2 (Table 5)

_________________________________________________63 ________________________________________________________Wh/m2 (Table 3)

Total heat loss/h ˆ Surface area  Heat loss

Surface area  Heat loss

___________________________________10 ________________________________________  ______________________2_______800 ________________________

____________________________________10 _________________________________________ _________________________63 ______________________________

____________________________________________________________________28 ____________000 _________________________________________________________________Wh/h

___________________________________________________________________________630 ______________________________________________________________________Wh/h

Annual heat loss ˆ Heat loss  h/yr

Heat loss/h  h/yr

__________________________28 ___________000 ______________________________________  ___________________8_______760 ___________________________

_______________________________630 ______________________________________________ ________________8_______760 ___________________________________________________

____________________________________________________245 ________________280 ________________000 ________________________________________________Wh/h (1)

_________________________________________________________5________518 ________________800 _________________________________________________Wh/yr (2)

Reduction in heat loss due to addition of insulation

ˆ

(1) ± (2)

ˆ _____________________________245 ________________280 ________________000 ___________________________________ ± ________5_______518 ________________800 _____________ ˆ _______________________________________________239 _________________761 ________________200 _____________________________________________________Wh/yr or _______________________239 ________________761 ________________200 ___________________________________Wh/yr  3.6 kJ/W ˆ __________________________________863 ________________140 ________________320 ___________________________________________________________________________kJ/yr Annual Rand savings may now be calculated using cost per unit of heating medium. Ensure that units are compatible.

35

WORKSHEET 1-3 Heat Loss From Piping Company: _____________________________________________XYZ __________________Co. _______________________________________________________________

Date: ___________________________________________________________________________________________________________________________________________________

Location: ________________________________________ANYTOWN __________________________________________________________________________________________ Low cost worked example No.3

By: ______________________________________________________________MBE _________________________________________________________________________________________

Equipment ______________________________Heating _____________________________tank _________________No. ________________2________________________________

Operating hours per year ___________________________________________8_______400 ______________________________________________________ h

Surface area __________________________________________________25 ________________________________________________________ m2

Proposed Insulation type __________________________________________________________________mineral ___________________________fibre _____________________________________________________

Product temperature __________________________________65 __________________________________________ oC

Proposed Insulation thickness _________________________________51 ________________________________________________ mm

Uninsulated

Insulated

Heat loss_______________________________________504.7 __________________________________Wh/m2 (Table 5)

_________________________________________________32 ________________________________________________________Wh/m2 (Table 3)

Total heat loss/h ˆ Surface area  Heat loss

Surface area  Heat loss

___________________________________25 ________________________________________  ______________________504.7 _______________________________

____________________________________25 _________________________________________ _________________________32 ______________________________

____________________________________________________________________12 ____________617.5 _________________________________________________________________Wh/h

___________________________________________________________________________800 ______________________________________________________________________Wh/h

Annual heat loss ˆ Heat loss  h/yr

Heat loss/h  h/yr

__________________________12 ___________617.5 ______________________________________  ________________________8________400 _____________________

_______________________________800 ______________________________________________ ________________8_______400 ___________________________________________________

____________________________________________________105 ________________987 ________________000 ________________________________________________Wh/h (1)

_________________________________________________________6________720 ________________000 _________________________________________________Wh/yr (2)

Reduction in heat loss due to addition of insulation

ˆ

(1) ± (2)

ˆ ____________________________105 _________________987 ________________000 ___________________________________ ± ________6_______720 ________________000 _____________ ˆ _______________________________________________99 ____________300 ________________000 __________________________________________________________Wh/yr or _______________________99 ____________300 ________________000 ___________________________________Wh/yr  3.6 kJ/Wh ˆ __________________________________357 ________________480 ________________000 ___________________________________________________________________________kJ/yr Annual Rand savings may now be calculated using cost per unit of heating medium. Ensure that units are compatible.

36

WORKSHEET 1-3 Heat Loss From Piping Company: _____________________________________________ABC _________________Co. ________________________________________________________________

Date: ___________________________________________________________________________________________________________________________________________________

Location: ________________________________________ANYTOWN __________________________________________________________________________________________ Low cost worked example No. 3

By: ______________________________________________________________MBE _________________________________________________________________________________________

Equipment ______________________________Holding ______________________________tank _________________No. ________________2_______________________________

Operating Hours per year _________________________________________8_______400 ______________________________________________________ h

Surface area _________________________________________________25 _________________________________________________________ m2

Proposed Insulation type __________________________________________________________________mineral ____________________________fibre ____________________________________________________

Product temperature __________________________________65 __________________________________________ oC

Proposed Insulation thickness _________________________________25 ________________________________________________ mm

Uninsulated

Insulated

Heat loss_______________________________________504.7 __________________________________Wh/m2 (Table 5)

_________________________________________________115 _________________________________________________Wh/mm2 (Table 3)

Total heat loss/h ˆ Surface area  Heat loss

Surface area  Heat loss

___________________________________25 ________________________________________  ______________________504.7 _______________________________

____________________________________25 _________________________________________ _________________________115 ______________________________

____________________________________________________________________12 ____________617.5 _________________________________________________________________Wh/h

___________________________________________________________________________2_______875 _______________________________________________________________Wh/h

Annual heat loss ˆ Heat loss  h/yr

Heat loss/h  h/yr

__________________________12 ___________617.5 ______________________________________  ________________________8________400 _____________________

_______________________________2_______875 _______________________________________ _______________________8________400 ___________________________________________

____________________________________________________105 ________________987 ________________000 ______________________________________________Wh/yr (1)

_________________________________________________________21 ____________150 ________________000 _____________________________________________Wh/yr (2)

Reduction in heat loss due to addition of insulation

ˆ

(1) ± (2)

ˆ _____________________________105 ________________987 ________________000 ___________________________________ ± _____21 ____________150 ________________000 ___________ ˆ _______________________________________________81 ____________837 ________________000 __________________________________________________________Wh/yr or _______________________81 ____________837 ________________000 ___________________________________Wh/yr  3.6 kJ/Wh ˆ __________________________________294 ________________613 ________________200 ___________________________________________________________________________kJ/yr Annual Rand savings may now be calculated using cost per unit of heating medium. Ensure that units are compatible.

37

WORKSHEET 1-2 (Page 1 of 2) Heat Loss From Piping Company: _____________________________________________ABC _________________Co. ________________________________________________________________

Date: ___________________________________________________________________________________________________________________________________________________

Location: ________________________________________ANYTOWN __________________________________________________________________________________________ Retrofit worked example No. 3

By: ______________________________________________________________MBE _________________________________________________________________________________________

Pipe diameter (NPS) _______________________________________4__________________________________________________

Pipe Length _____________________________________________________350 ___________________________________________________________ m

Pipe temperature _________________________________________121 ________________________________________________ oC

Operating Hours per year ____________________________________4________400 __________________________________________________________ h

Proposed insulation type ___________________________________mineral ____________________________fibre ________________________________________________

Proposed Insulation thickness _________________________________76 ________________________________________________ mm

Uninsulated

Insulated

Heat loss_______________________________________530 ________________________________Wh/m.h (Table 1)

_________________________________________________28 _____________________________________________________Wh/m.h (Table 3)

Heat loss/h ˆ Heat loss/m.h  length

Heat loss/m.h  length

___________________________________530 ________________________________________  __________________________350 ___________________________

___________________________________28 __________________________________________ _________________________350 ______________________________

___________________________________________________________185 ________________500 ______________________________________________________________________Wh/h

___________________________________________________________________________9_______800 _______________________________________________________________Wh/h

Annual heat loss ˆ Heat loss  h/yr

Heat loss/h  h/yr

__________________________185 ________________500 _________________________________  _______________________4_______400 _______________________

_______________________________9_______800 _______________________________________ _______________________4_______400 ____________________________________________

____________________________________________________816 ________________200 ________________000 ________________________________________________Wh/h (1)

_________________________________________________________43 ____________120 ________________000 _____________________________________________Wh/yr (2)

Reduction in heat loss due to addition of insulation

ˆ

(1) ± (2)

ˆ ____________________________816 _________________200 ________________000 ___________________________________ ± _____43 ____________120 ________________000 ___________ ˆ _______________________________________________773 ________________080 _________________000 _____________________________________________________Wh/yr or _______________________773 ________________080 ________________000 _______________________________Wh/yr  3.6 kJ/Wh ˆ __________________________________2_______783 ________________088 ________________000 ____________________________________________________________________kJ/yr Annual Rand savings may now be calculated using cost per unit of heating medium. Ensure that units are compatible.

38

WORKSHEET 1-2 (Page 2 of 2) Heat Loss From Piping Company: _____________________________________________ABC _________________Co. ________________________________________________________________

Date: ___________________________________________________________________________________________________________________________________________________

Location: ________________________________________ANYTOWN __________________________________________________________________________________________ Retrofit worked example No. 3

By: ______________________________________________________________MBE _________________________________________________________________________________________

Pipe diameter (NPS) ________________________________________________4_________________________________________

Pipe Length _________________________________________________________350 _______________________________________________________ m

Pipe temperature __________________________________________________________121 _______________________________ oC

Operating Hours per year _________________________________________4_______400 ______________________________________________________ h

Proposed insulation type ___________________________________mineral ____________________________fibre ________________________________________________

Proposed Insulation thickness _________________________________25 ________________________________________________ mm

Uninsulated

Insulated

Heat loss Per metre ________________________________530 _________________________________Wh/m.h (Table 1)

_________________________________________________200 _____________________________________________________Wh/m.h (Table 3)

Heat loss/h ˆ Heat loss/m.h  length

Heat loss/m.h  length

___________________________________530 ________________________________________  __________________________350 ___________________________

____________________________________200 _________________________________________ _____________________________350 __________________________

______________________________________________________________________185 ________________500 ___________________________________________________________Wh/h

__________________________________________________________________70 ____________000 ___________________________________________________________________Wh/h

Annual heat loss ˆ Heat loss  h/yr

Heat loss/h  h/yr

__________________________185 ________________500 _________________________________  ____________________4_______400 __________________________

_______________________________70 ____________000 __________________________________ ___________________________4________400 _______________________________________

___________________________________________816 ________________200 ________________000 _______________________________________________________Wh/yr (1)

_________________________________________________________308 ________________000 ________________000 _________________________________________Wh/yr (2)

Reduction in heat loss due to addition of insulation

ˆ

(1) ± (2)

ˆ __________________________816 _______________200 ________________000 _______________________________________ ± _308 ________________000 ________________000 ___________ ˆ _______________________________________________508 _________________200 ________________000 _____________________________________________________Wh/yr or _______________________508 ________________200 ________________000 _______________________________Wh/yr  3.6 kJ/Wh ˆ __________________________________1_______829 ________________520 _________________000 ___________________________________________________________________kJ/yr Annual Rand savings may now be calculated using cost per unit of heating medium. Ensure that units are compatible.

39

GLOSSARY

Ambient Temperature ± The temperature of the medium, usually air, surrounding the object under consideration. Batt ±

the liquid being the surface tension. Caulking Compound ± A soft, plastic material, consisting of pigment and carrier, used for sealing joints in buildings, and other structures, where normal structural movement may occur.

A piece of insulation, of the flexible type, cut into easily handled sizes, square or rectangular in shape, usually 609.6 mm (24º) or 1219 mm (48º) long with a vapour retarder on one side, and with, or without, a container sheet on the other side.

Cellular Elastomeric Flexible Thermal Insulation ± Insulation composed principally of natural or synthetic elastomers in expanded cellular form.

Blanket ± Insulation, of the flexible type, formed into sheets or rolls, usually with a vapour retarder on one side, and with, or without, a container sheet on the other side.

Cellular Glass Thermal Insulation ± Insulation composed of glass processed by fusion to form a homogeneous rigid mass of closed cells.

Block ± Rigid or semi-rigid insulation formed into sections, rectangular both in plan and cross-section, usually 36º (914.4 mm) to 1219 mm (48º) long, 152.4 mm (6º) to 609.6 mm (24º) wide, and 25.4 mm (1º) to 152.4 mm (6º) thick.

Celsius ± The temperature measuring scale (formerly Centigrade) in which the freezing point of water is taken at 0o and the vaporisation point at 100o. Absolute zero on this scale is -273.15oC. Chemically Foamed Plastic ± A cellular plastic produced by gasses generated from chemical interaction of constituents.

Calcium Silicate Insulation ± Insulation composed principally of hydrous calcium silicate, which usually incorporates fibres of varying types to act as a binder. Canvas ± A light, plain weave, coarse, cotton cloth with hard twisted yarns, usually not more than 271 grams per square metre.

Chlorinated Solvent ± An organic chemical liquid characterised by a high chlorine content and used in coating products to impart non-flammability.

Capillarity ± That property of a material which enables it to suck a liquid up into or through itself, with the driving force of

Closed-Cell Foamed Plastic ± A cellular plastic in which there is a predominance of noninterconnecting cells.

40

Coating ± A liquid, or semi-liquid, protective finish suitable for thermal insulation or other surfaces, usually applied by brush or spray, in moderate thickness, less than 0.80 mm approx. [30 mils (0.030º)].

contact: also called contact bond or dry bond adhesive. Corrosion Effect ± The wearing away' or destruction of a substrate caused by acid or alkaline reactions between materials contained in the insulation and substrate.

Coefficient of Expansion (Contraction) ± The increase (decrease) in length of a material one unit long, due to the increase (decrease) of temperature by one degree.

Coverage-Wet ± The property of a material which measures the thickness of wet material that must be applied to a given area to obtain a specific thickness after it has cured and dried.

Combustible ± Capable of uniting with air or oxygen in a reaction initiated by heating accompanied by the subsequent evolution of heat and light i.e. capable of burning.

Cryogenic ± Pertaining to the extremely low temperatures, such as the liquefaction points of gaseous elements, usually approaching absolute zero (-273.15oC).

Combustibility ± That property of a material which measures its tendency to burn. It is normally expressed in the arbitrary terms of ªFlame Spread Indexº and ªSmoke Density Indexº

Curing Agent ± An additive incorporated in a coating or adhesive resulting in increased chemical activity between the components, with an increase or decrease in the rate of cure.

Compressive Strength ± Resistance to change in dimension when acted on by a compacting force.

Curved Segmental Block ± A piece of rigid pipe insulation, moulded or cut from a block to fit the exact dimensions of a given size of pipe.

Condensation ± The act of water vapour turning into water upon contact with a surface at a lower temperature than the dew point of the vapour.

Density ± The mass per unit volume of a substance.

Conductivity ± See Thermal Conductance.

Dewpoint ± The temperature at which the quantity of water vapour in a material would cause saturation, with resultant condensation of the vapour into liquid water by any further reduction of temperature.

Contact Adhesive ± An adhesive which is apparently dry to the touch and which will adhere to itself instantaneously' upon

Diatomaceous Silica Insulation ± Insulation composed principally of diatomaceous earth with, or without, heat-resistant inorganic

Conduction ± The transfer of energy within a body, or between two bodies in physical contact, from a higher temperature region to a lower temperature region.

41

of 212o with 180 even divisions between and corresponding divisions above and below. Absolute zero on this scale is 459.67o.

binders and which usually incorporates mineral fibres. Dimensional Stability ± That property of insulation, which enables it to hold its original size, shape and dimensions.

Felt ± An insulation material composed of fibres, which are interlocked and compacted under pressure.

Drying Time (Adhesives) ± Time elapsed since bonding and the time when no further increase in bond strength is realised.

Fibreglass ± A composite material consisting of glass fibres and a resin binder.

Drying Time (Finishes) ± Time elapsed after which no further significant changes take place in appearance or performance properties, due to drying.

Filler ± A relatively inert material added to a mastic or coating to modify its strength, permeance, working properties, or other qualities.

Ductility ± That property of a material which enables it to undergo large deformations without rupture.

Finishing Cement ± A mixture of fibres, bonding clays, and water mixed to a plastic mass on the job, and used on the surface of insulation to provide a medium-hard to hard, even finish.

Elastomer ± Material, which at room temperature can be stretched repeatedly to at least twice its original length and immediately upon release of the stress, will return with force to the approximate original length.

Fire Resistance ± That property of a material that enables it to resist decomposition or deterioration when exposed to a fire.

Emittance ± The ratio of the total heat lost per unit of time through the same unit area of a perfect blackbody.

Fire Retardance ± That property of a material, which delays the spread of fire, either through or over itself.

Exposed ± Any surface, which will be visible in the finished structure.

Flame Spread ± The rate, expressed in distance and time, at which a material will propagate flame on its surface. As this is a difficult property to measure in time and distance, the measure is now by flame spread index to enable the comparison of materials by one of the following test methods: CAN2- S102-M83 or ASTM E84.

Facing ± A thin layer on the surface of an insulating product, acting as either a vapour retarder, weather barrier, protector from damage or a decorative coating. Fahrenheit ± The temperature scale of The British System of units in which the freezing point of water is assigned the value of 32o and the vaporisation point the value

Flammable ± That property of a material which permits it to oxidise rapidly and release

42

heat of combustion when exposed to flame or fire, and allows continuous burning after the external ignition source is removed.

Insulation ± A material of low thermal conductivity used to reduce the passage of heat. Insulation Coating ± A material, or materials, used over insulation or over the weather coating to provide the desired colour or texture for decorative purposes.

Flashing ± A thin strip of metal inserted at the junction of 2 materials to divert water in a specific direction.

Insulation Cover ± The cover for a flange, pipefitting, or valve, composed of the specified thickness of insulating material, and pre-formed into the proper shape before application.

Flash Point ± The lowest temperature of a material (at a fixed pressure) at which it gives off vapour, which, when combined with air near the surface, forms an ignitable mixture.

Insulation System ± An application of insulation to piping, ductwork or equipment that may include the use of adhesives, mechanical fastenings, coatings, reinforcing fabrics, sealant and metal covering.

Flexibility ± That property of a material, which allows it to be bent (flexed) without loss of strength. Flexural Strength ± That property of a material which measures its resistance to bending (flexing) usually expressed in kg/m (lbs/ in).

Jacket ± A covering placed around an insulation to protect it from mechanical damage, and, insofar as it is intrinsically able, from weather, water, ultraviolet light, etc.

Freeze-Thaw Resistance ± The property of a material which permits it to be alternately frozen and thawed through many cycles without damage from rupture or cracking.

Lag ± A long, narrow piece of rigid insulation, rectangular in plan, trapezoidal in crosssection, moulded, or cut from a block of the proper thickness.

Fuel Contribution ± Flammable by-products of fire generated by, and emitted from, a burning object.

Lagging ± An insulation layer, on a cylindrical surface, composed of lags. Laminated Foils ± A product made by bonding a foil sheet to at least one other material such as kraft paper.

Hanger ± A device such as a welded pin, stud or adhesive secured fastener, which carries the weight of the insulation or piping system.

Lap Adhesive (Lap Cement) ± The adhesive material used to seal the side and end laps of insulation jackets.

Humidity ± A measure of the amount of water vapour in the atmosphere.

Linear Shrinkage ± The property of a material that indicates the proportional loss of dimen-

43

sions when exposed to high temperatures.

Pipe Insulation ± Thermal insulation suited for application to cylindrical surfaces of pipe and tubing.

Loose Fill Insulation ± Particulate material in granular, nodular, fibrous, powdery, or similar form designed to be installed dry by pouring, blowing, or hand placement between retaining surfaces or as a covering layer.

Pre-formed Pipe Insulation ± Thermal insulation in cylindrical, semi-cylindrical, or segmental sections to fit pipes and tubing. Pre-formed Thermal Insulation Block ± A rigid or semi-rigid thermal insulating material, either flat or segmental, for application as received.

Mastic ± A relatively thick consistency protective finish capable of application to thermal insulation or other surfaces, usually by spray or trowel, in thick coats greater than 30 mils (0.80 mm approximately).

Primer ± The first application of a coating system used to seal or condition the surface for the proper bonding of subsequent layers or coats.

Metal Lath ± A lattice type of material of various gauges and sizes used to provide reinforcement for insulation.

PVC-Polyvinyl Chloride ± Plastic material moulded into finished shapes such as fitting covers.

Mineral Fibre (Wool) ± A generic term for all nonmetallic inorganic fibres, which may be natural, or may be manufactured from such sources as rock, slag, or glass.

Reflective Insulation ± Thermal insulation depending for its efficiency in large part on the reduction of radiant heat transfer across spaces by use of one or more surfaces of high reflectance and low emittance.

Mineral Fibre Blanket Insulation ± A blanket thermal insulation composed of inorganic fibres, with, or without, added binders.

Reinforcing Membrane ± A loosely woven cloth or fabric of glass or resilient fibres, placed approximately in the centre of the vapour retarder or weather barrier to act as reinforcing to the mastic of the barrier.

Mitred Insulation ± Insulation that has been cut in bevelled sections so that when it is fitted together, it follows the contour or curve of the object being insulated. Non-combustible ± A material that will not contribute fuel or heat to a fire to which it is exposed.

Scrim ± Woven screening type fabric used to reinforce an insulation covering. Tack ± The property of an adhesive that enables it to form a bond of measurable strength immediately after adhesive and adherent are brought into contact under low pressure.

Non-flammable ± That property of a material that prevents it from oxidising rapidly and releasing heat or combustion when exposed to fire or flame.

44

Temperature Limits ± The upper and lower temperatures at which a material will experience no essential change in its properties.

formed by the mating surfaces of jackets and vapour retarders over insulation. A good sealer will not shrink much. There are several types of sealers, such as nonsetting, and heat resisting.

Thermal Insulation ± Material having air-filled or gas-filled pockets, void spaces, or heatreflective surfaces, which, when properly applied will retard the transfer of heat with reasonable effectiveness under ordinary conditions.

Service Temperature Limits ± The temperature range within which the applied coating will provide satisfactory service. Smoke Density (Smoke Developed) ± The Smoke Density Factor is the amount of smoke given off by the burning material compared to the amount of smoke given off by the burning of a standard material.

Reinforcing Mesh ± Generic term for poultry netting, chicken wire, etc., usually made from pre-galvanised wire woven in 25.4 mm (1 inch) mesh size. Also available in post-galvanised and rustless metal alloys.

Softening Point ± That temperature at which a material will change its property from firm or rigid to soft or malleable.

Relative Humidity ± The ratio of the actual pressure of existing water vapour to the maximum possible (saturation) pressure of water vapour in the atmosphere at the same temperature, expressed as a percentage. (See Dewpoint.)

Solvent ± Any substance, usually a liquid, which dissolves another substance. Normally a liquid organic compound used to make a coating work more freely.

Resilient ± Capable of recoiling from pressure or shock unchanged or undamaged.

Substrate ± A material upon the surface of which an adhesive or coating is spread.

Sag ± Excessive flow in material after application to a surface, resulting in ªcurtainingº or running.

Thermal Shock Resistance ± That property of a material which enables it to maintain shape and not distort, crack or shatter, from a sudden temperature change.

Self-Ignition Temperature (Autogeneous Ignition) ± The lowest temperature of a material which will cause it to ignite without another ignition source.

Thermoplastic ± Capable of being repeatedly softened by an increase of temperature. Note: Thermoplastic applies to those materials whose change upon heating is substantially physical.

Self-Extinguishing ± That property of a material which enables it to stop ignition after external ignition sources are removed.

Thermoset ± A plastic or other coating which, when cured by the application of heat or chemical means, changes to a substantially infusible and insoluble product.

Sealer ± A substance, composed of various materials, used as a barrier to the passage of water vapour or water into the joint

45

Toxicity ± The degree of hazard to health.

Viscosity ± The property of resistance to flow exhibited within the body of a material.

Urethane Resins ± Resins made by the condensation of organic isocyanates with compounds or resins that contain hydroxol groups. Note: Urethanes are a type of isocyanates resins.

Water Absorption ± The increase in weight of a material, expressed as a percentage of its dry weight, after immersion in water for a specified time.

Vapour Retarder ± A material, or materials, which when installed on the high vapour pressure side, retards the passage of the moisture vapour to the lower vapour pressure side.

Weather Barrier ± A material, which, when installed on the outside of the insulation, protects the insulation from weather damage due to rain, snow, wind, atmospheric contamination, etc.

Vapour Migration (Permeability) ± That property of a material, which measures the rate at which water vapour will penetrate it, due to vapour pressure differences between its surfaces.

Weather Coating ± A material, or materials, which, when installed on the outer surface of thermal insulation, protects the insulation from weather, such as rain, snow, sleet, wind, solar radiation, and atmospheric contamination.

Vapour Pressure ± The gas pressure exerted by the water vapour present in the air.

Wire Netting ± Interwoven wires of metal used as reinforcement for insulation.

Vermiculite ± Lightweight insulation material made from the expansion of granules at high temperatures.

Wicking ± The ability of a material to draw up liquids by capillary action.

Victaulic ± A trade or patented name for a specific type of coupling.

46

HEAT LOSS TABLES

47

48

49

50

51

HEAT LOSS TABLES

HEAT LOSS THROUGH PIPES WITH VARIOUS THICKNESSES OF INSULATION TABLE 3 CELLULAR GLASS PROCESS TEMPERATURE (oC)

NPS 66

121

177

232

288

343

399

0.5

Thickness heat loss surf. temp

25 12 24

38 25 26

51 37 28

64 49 28

76 61 29

89 72 30

102 86 31

1

Thickness heat loss surf. temp

25 16 24

51 28 25

64 41 27

76 55 28

89 68 29

102 83 30

102 102 32

1.5

Thickness heat loss surf. temp

38 17 23

64 31 24

76 46 26

102 58 27

102 77 29

102 98 31

102 121 33

2

Thickness heat loss surf. temp

38 14 22

64 35 25

76 51 27

102 64 27

102 86 29

102 110 32

114 128 32

3

Thickness heat loss surf. temp

38 25 24

76 39 24

89 60 26

102 79 26

102 106 31

114 127 32

127 148 33

4

Thickness heat loss surf. temp

51 25 23

76 46 25

102 64 26

102 92 28

102 123 31

114 147 32

127 170 33

6

Thickness heat loss surf. temp

51 34 23

89 54 24

102 82 27

102 118 29

114 147 31

140 165 31

152 193 33

8

Thickness heat loss surf. temp

64 36 23

86 65 25

98 99 27

98 142 31

123 163 31

135 196 32

159 217 33

10

Thickness heat loss surf. temp

64 42 23

102 70 24

102 116 28

102 167 31

140 179 31

140 229 33

178 239 32

52

TABLE 3 (CELLULAR GLASS ± Continued) PROCESS TEMPERATURE (oC)

NPS 66

121

177

232

288

343

399

12

Thickness heat loss surf. temp

64 48 23

102 80 25

102 133 28

102 191 32

140 203 31

140 258 34

191 258 32

14

Thickness heat loss surf. temp

64 53 23

102 87 25

102 142 28

102 206 32

140 217 31

140 277 34

203 262 31

16

Thickness heat loss surf. temp

64 59 23

102 96 25

102 159 28

102 229 32

140 240 31

140 307 34

203 288 32

18

Thickness heat loss surf. temp

64 65 23

102 106 25

102 175 29

102 255 32

140 263 31

140 337 34

203 314 32

20

Thickness heat loss surf. temp

64 71 23

102 115 26

102 191 29

114 251 31

140 287 32

140 365 34

203 340 32

24

Thickness heat loss surf. temp

64 84 23

102 135 26

102 223 29

127 268 30

140 333 32

140 425 35

203 391 32

30

Thickness heat loss surf. temp

64 103 24

102 164 26

102 271 29

140 300 29

140 402 32

140 512 36

203 467 33

36

Thickness heat loss surf. temp

64 122 24

102 193 26

102 319 29

140 352 29

140 470 33

140 600 36

203 543 33

FLAT

Thickness heat loss surf. temp

64 41 406

102 63 25

102 101 28

140 107 28

140 145 31

191 136 31

216 148 32

Heat loss: Wh/m for pipe, Wh/m2 for flat surfaces Based on 18oC ambient temperature

53

HEAT LOSS THROUGH PIPES WITH VARIOUS THICKNESSES OF INSULATION TABLE 3 CALCIUM SILICATE PROCESS TEMPERATURE (oC)

NPS 66

121

177

232

288

343

399

454

510

566

0.5

Thickness heat loss surf. temp

25 8 22

38 15 24

51 23 24

64 32 26

76 41 26

89 52 27

102 63 28

102 81 30

114 96 31

140 110 31

1

Thickness heat loss surf. temp

25 11 23

25 20 24

51 29 26

64 39 27

89 47 26

102 59 27

102 76 29

114 92 30

127 110 31

140 130 32

1.5

Thickness heat loss surf. temp

25 13 23

51 21 23

64 32 25

76 43 26

102 52 26

102 70 28

102 90 30

140 99 29

140 123 31

152 146 32

2

Thickness heat loss surf. temp

38 12 22

51 24 24

76 23 24

89 45 25

102 59 26

102 78 28

102 101 31

140 110 29

152 132 31

152 162 33

3

Thickness heat loss surf. temp

38 15 22

64 27 23

89 37 24

102 52 25

102 72 27

114 90 28

114 117 31

152 128 30

165 148 31

178 177 32

4

Thickness heat loss surf. temp

38 18 22

76 28 23

102 40 23

102 61 26

102 85 28

127 98 30

140 121 29

152 146 31

178 167 31

191 198 32

6

Thickness heat loss surf. temp

51 20 22

76 37 23

102 52 24

102 78 26

114 100 28

127 125 29

140 153 31

165 174 31

191 200 32

203 237 33

8

Thickness heat loss surf. temp

51 25 22

86 40 23

98 62 24

98 93 27

123 112 27

123 149 29

135 182 32

172 196 31

196 225 32

208 266 33

10

Thickness heat loss surf. temp

51 31 22

89 48 23

102 74 25

102 111 27

127 130 28

140 163 29

140 212 32

191 217 31

216 249 32

229 295 33

54

TABLE 3

(CALCIUM SILICATE ± Continued) PROCESS TEMPERATURE (oC)

NPS 66

121

177

232

288

343

399

454

510

566

12

Thickness heat loss surf. temp

64 45 23

102 72 24

102 116 27

102 163 30

127 184 30

140 256 32

178 227 31

203 252 31

216 288 32

241 317 33

14

Thickness heat loss surf. temp

64 49 23

102 78 24

102 125 27

102 176 30

127 197 31

140 233 32

178 242 31

203 252 31

229 296 32

241 338 33

16

Thickness heat loss surf. temp

76 48 22

102 87 24

102 138 28

102 196 31

140 203 29

191 228 30

203 255 31

229 295 32

254 325 32

254 358 33

18

Thickness heat loss surf. temp

76 53 23

102 95 24

102 153 28

102 216 31

140 223 30

165 249 31

191 278 31

216 308 31

229 353 32

254 387 33

20

Thickness heat loss surf. temp

76 58 23

102 104 25

102 167 28

102 236 31

140 242 30

165 270 31

191 300 31

216 333 32

241 366 32

254 418 33

24

Thickness heat loss surf. temp

76 68 23

102 122 25

102 195 28

102 276 31

140 282 31

165 312 31

191 346 31

216 382 32

241 420 32

254 478 34

30

Thickness heat loss surf. temp

76 83 23

102 148 25

102 237 28

102 336 31

140 339 31

178 354 31

203 393 31

229 435 32

254 479 32

254 566 34

36

Thickness heat loss surf. temp

64 114 23

102 174 25

102 280 28

102 394 32

165 345 29

191 390 30

203 457 31

229 504 32

254 554 33

254 655 34

FLAT

Thickness heat loss surf. temp

64 38 23

89 63 25

102 88 27

140 91 27

165 104 28

191 114 29

216 123 29

241 136 31

254 155 32

254 183 34

Heat loss: Wh/m for pipe, Wh/m2 for flat surfaces Based on 18oC ambient temperature

55

HEAT LOSS THROUGH PIPES WITH VARIOUS THICKNESSES OF INSULATION TABLE 3 MINERAL FIBRE PROCESS TEMPERATURE (oC)

NPS 66

121

177

232

288

343

399

454

510

566

0.5

Thickness heat loss surf. temp

25 8 22

38 15 24

51 23 24

64 32 26

76 41 26

89 52 27

102 63 28

102 81 30

114 96 31

140 110 31

1

Thickness heat loss surf. temp

25 11 23

25 20 24

51 29 26

64 39 27

89 47 26

102 59 27

102 76 29

114 92 30

127 110 31

140 130 32

1.5

Thickness heat loss surf. temp

25 13 23

51 21 23

64 32 25

76 43 26

102 52 26

102 70 28

102 90 30

140 99 29

140 123 31

152 146 32

2

Thickness heat loss surf. temp

38 12 22

51 24 24

76 23 24

89 45 25

102 59 26

102 78 28

102 101 31

140 110 29

152 132 31

152 162 33

3

Thickness heat loss surf. temp

38 15 22

64 27 23

89 37 24

102 52 25

102 72 27

114 90 28

114 117 31

152 128 30

165 148 31

178 177 32

4

Thickness heat loss surf. temp

38 18 22

76 28 23

102 40 23

102 61 26

102 85 28

127 98 30

140 121 29

152 146 31

178 167 31

191 198 32

6

Thickness heat loss surf. temp

51 20 22

76 37 23

102 52 24

102 78 26

114 100 28

127 125 29

140 153 31

165 174 31

191 200 32

203 237 33

8

Thickness heat loss surf. temp

51 25 22

86 40 23

98 62 24

98 93 27

123 112 27

123 149 29

135 182 32

172 196 31

196 225 32

208 266 33

10

Thickness heat loss surf. temp

51 31 22

89 48 23

102 74 25

102 111 27

127 130 28

140 163 29

140 212 32

191 217 31

216 249 32

229 295 33

56

TABLE 3

(MINERAL FIBRE ± Continued) PROCESS TEMPERATURE (oC)

NPS 66

121

177

232

288

343

399

454

510

566

12

Thickness heat loss surf. temp

51 35 22

89 55 23

102 84 25

102 126 28

127 148 28

140 185 30

140 239 33

191 243 31

216 279 32

241 318 33

14

Thickness heat loss surf. temp

51 38 22

89 59 23

102 90 25

102 136 28

127 259 28

140 198 30

165 227 31

191 261 32

229 286 32

241 338 33

16

Thickness heat loss surf. temp

64 36 22

89 65 23

102 101 26

102 151 28

140 164 28

178 219 31

203 237 30

229 273 31

254 313 32

254 358 33

18

Thickness heat loss surf. temp

64 39 22

89 72 23

102 111 26

102 166 28

140 180 28

140 240 31

178 260 31

203 298 31

229 340 32

254 388 33

20

Thickness heat loss surf. temp

64 43 22

89 79 24

102 121 26

102 182 28

140 196 28

140 262 31

178 281 31

203 322 32

229 368 32

254 419 33

24

Thickness heat loss surf. temp

64 51 22

102 83 23

102 141 26

102 212 28

140 228 28

152 284 30

191 308 30

203 371 32

229 422 33

254 479 34

30

Thickness heat loss surf. temp

64 62 22

102 101 23

102 172 26

102 258 29

140 275 29

165 319 29

191 368 31

216 422 32

254 462 32

254 568 34

36

Thickness heat loss surf. temp

64 74 22

102 118 23

102 203 26

102 304 29

140 322 29

178 350 29

203 406 30

229 467 31

254 535 32

254 657 34

FLAT

Thickness heat loss surf. temp

51 32 22

89 44 23

102 63 25

114 85 27

140 98 28

216 85 27

241 98 28

254 120 29

254 148 32

254 183 34

Heat loss: Wh/m for pipe, Wh/m2 for flat surfaces Based on 18oC ambient temperature

57

Thermal properties of typical building and insulation materials ± DESIGN VALUES TABLE 4 MINERAL FIBRE Description

Density kg/m3

Conductivity k W/m.oC

4.8-32.0 4.8-32.0 4.8-32.0 4.8-32.0 4.8-32.0 4.8-32.0

Ð

Conductance Resistance (R) Specific (C) Heat Per inch thickness For thick.oC) W/m2.oC kJ/(kg (1/k) m.oC ness listed (1/C) m2.oC

INSULATING MATERIALS Blanket and Batt Mineral Fibre, fibrous form processed from rock, slag, or glass approx. approx. approx. approx. approx. approx.

76.2-101.6 mm 88.9 mm 139.7-165.1 mm 152.4-177.8 mm 215.9-228.6 mm 304.8 mm

Ð Ð Ð

Ð

0.52 0.44 0.30 0.26 0.19 0.15

1.94 2.29 3.34 3.87 5.28 6.69

136 64-144 16.0 72.0

0.050 0.036 0.052 0.032

Ð Ð Ð Ð

19.85 27.76 19.29 31.58

Ð Ð Ð Ð

0.75 0.96 1.26 1.68

28.8 28.8-56.0

0.036 0.029

Ð Ð

27.76 34.70

Ð Ð

1.22 1.22

16.0 20.0 24.0 28.0 32.0

0.037 0.036 0.035 0.035 0.033

Ð Ð Ð Ð Ð

23.25 27.76 28.94 28.94 30.19

Ð Ð Ð Ð Ð

Ð Ð Ð Ð Ð

Ð

Board and Slabs Cellular glass Glass fibre, organic bonded Expanded perlite, organic bonded Expanded rubber (rigid) Expanded polystyrene extruded Cut cell surface Smooth skin surface Expanded polystyrene, moulded beads

58

TABLE 4 Description

(MINERAL FIBRE ± Continued) Density kg/m3

Conductivity k W/m.oC

Cellular polyurethane (R-11 exp.) 0.023 24.0 (unfaced) Foil-faced, glass fibre-reinforced cellular 0.020 32.0 Polyisocyanurate (R-11 exp.) Ð Nominal 12.70 mm Ð Nominal 25.40 mm Ð Nominal 50.80 mm 0.042 240 Mineral fibre with resin binder Mineral fibreboard, wet felted 0.049 256-272 Core or roof insulation 0.050 288 Acoustical tile 0.0563 336 Acoustical tile Mineral fibreboard, 0.060 368 wet moulded Acoustical tile Wood or cane fibreboard Ð Ð Acoustical tile 12.70 mm Ð Ð Acoustical tile 19.05 mm 0.050 240 Interior finish (plank, tile) Cement fibre slabs (shredded wood with 400-432 0.072-0.070 Portland cement binder) Cement fibre slabs (shredded wood with 0.082 352 magnesia oxysulfide binder) FIELD APPLIED Polyurethane foam Spray cellulosic fibre base

24.0-40.0 0.023-0.026 32.0-96.0 0.035-0.043

59

Conductance (C) W/m2.oC

Resistance (R)

Specific Heat Per inch For thickkJ/(kg.oC) thickness (1/k) ness listed m.oC (1/C) m2.oC 43.38

Ð

1.59

Ð 1.58 0.79 0.39 Ð

49.97 Ð Ð Ð 23.94

Ð 0.63 1.27 2.53 Ð

0.92

Ð Ð Ð

20.40 19.85 18.74

Ð Ð Ð

0.80

Ð

16.52

Ð

0.59

4.54 3.01 Ð

Ð Ð 19.85

0.22 0.33 Ð

1.30 Ð 1.34

Ð

13.88-13.12

Ð

Ð

Ð

12.15

Ð

1.30

Ð Ð

43.38-36.50 23.11-28.94

Ð Ð

0.71

Thermal conductivity (k) of industrial insulation ± DESIGN VALUES W/m.oC TABLE 5 Form Material Composition

Accepted Typical Max Density Temp for (kg/m3) Use, oC

Typical Conductivity k at Mean Temp oC 73.3 59.4 45.6 31.7 17.8 3.9 10.0 23.9 37.8 93.3 148.9 260.0 371.1 482.2

BLANKETS & FELTS MINERAL FIBRE (Rock, slag or glass) Blanket, metal reinforced

650 540

Mineral fibre, glass Blanket, flexible, fine-fibre organic bonded

180

Blanket, flexible, textile-fibre organic bonded

180

96-192 40.0-96.0 (

0.037 0.046 0.056 0.078 0.035 0.045 0.058 0.088

less than 12.0

0.036 0.037 0.040 0.043 0.048 0.052 0.076

16.0

0.033 0.035 0.036 0.039 0.042 0.046 0.062

24.0

0.030 0.032 0.033 0.036 0.039 0.040 0.053

32.0

0.029 0.030 0.032 0.033 0.036 0.037 0.048

48.0

0.027 0.029 0.030 0.032 0.033 0.035 0.045

10.4

0.039 0.040 0.042 0.043 0.045 0.046 0.072 0.098

12.0

0.037 0.039 0.040 0.042 0.045 0.046 0.069 0.095

16.0

0.035 0.036 0.037 0.039 0.042 0.045 0.065 0.086

24.0

0.032 0.033 0.035 0.036 0.039 0.042 0.056 0.073

48.0

0.029 0.030 0.032 0.033 0.035 0.036 0.046 0.059

0.035 0.036 0.039 0.042 0.046 0.049 0.069

0.035 0.036 0.037 0.039 0.050 0.063

Felt, semi-rigid organic bonded

200

Laminated & felted

450 650

48-128 0.023 0.024 0.026 0.027 0.039 0.030 0.032 0.033 0.035 0.050 0.079 48.0 0.050 0.065 0.0/86 120

VEGETABLE & ANIMAL FIBRE Hair Felt or Hair Felt plus Jute

80

160

0.037 0.040 0.042 0.043

60

TABLE 5 (Thermal conductivity (k) of industrial insulation ± Continued) Form Material Composition

Accepted Typical Max Density Temp for (kg/m3) Use, oC

Typical Conductivity k at Mean Temp oC 73.3 59.4 45.6 31.7 17.8 3.9 10.0 23.9 37.8 93.3 148.9 260.0 371.1 482.2

BLOCKS, BOARDS & PIPE INSULATION ASBESTOS Laminated asbestos paper

370

480

4-ply

150

176-208

0.078 0.082 0.098

6-ply

150

240-272

0.071 0.073 0.085

8-ply

150

288-320

0.068 0.071 0.082

MOULDED AMOSITE & BINDER

820

240-288

0.046 0.053 0.060 0.075 0.089 0.104

85% MAGNESIA

320

176-192 192

0.050 0.055 0.060

CALCIUM SILICATE

650

176-240

0.055 0.059 0.063 0.075 0.089 0.104

980

192-240

0.091 0.107 0.137

CELLULAR GLASS

480

136

DIATOMACEOUS SILICA

870

336-352

0.092 0.098 0.104

1040

368-400

0.101 0.108 0.105

Organic bonded, block and boards

200

48-160 0.023 0.024 0.026 0.027 0.029 0.032 0.035 0.036 0.037 0.048 0.058

Non-punking binder

540

48-160

Pipe insulation, slag or glass

180

48.0-64.0

0.058 0.065 0.072 0.086

Corrugated & laminated asbestos Paper

0.039 0.040 0.042 0.043 0.045 0.046 0.048 0.050 0.052 0.060 0.071 0.101 0.148

MINERAL FIBRE Glass,

0.037 0.045 0.055 0.075 0.029 0.032 0.033 0.035 0.042

Inorganic bonded-block Pipe insulation slag or glass

260

48-160

540

160-240

0.048 0.055 0.065 0.079

980

240-384

0.046 0.053 0.060 0.075 0.089 0.107

540

160-240

0.048 0.055 0.065 0.079

0.029 0.035 0.036 0.037 0.048 0.058

61

TABLE 5E (Thermal conductivity (k) of industrial insulation ± Continued) Form Material Composition

Accepted Typical Max Density Temp for (kg/m3) Use, oC

Typical Conductivity k at Mean Temp oC 73.3 59.4 45.6 31.7 17.8 3.9 10.0 23.9 37.8 93.3 148.9 260.0 371.1 482.2

MINERAL FIBRE Resin binder

240

0.033 0.035 0.036 0.037 0.040 0.042

RIGID POLYSTYRENE Extruded, Refrigerant 12 exp. smooth skin surface

80

35.2

0.023 0.023 0.024 0.023 0.024 0.026 0.027 0.029

Extruded cut cell surface

80

28.8

0.024 0.026 0.027 0.029 0.030 0.033 0.035 0.036 0.039

Moulded beads

80

16.0

0.024 0.027 0.029 0.030 0.032 0.035 0.036 0.037 0.040

24.0

0.023 0.024 0.027 0.029 0.030 0.032 0.033 0.035 0.037

20.0

0.024 0.026 0.027 0.029 0.032 0.033 0.035 0.036 0.039

28.0

0.023 0.024 0.026 0.027 0.029 0.032 0.033 0.035 0.036

32.0

0.022 0.023 0.026 0.027 0.029 0.030 0.032 0.033 0.035

32.0

0.017 0.019 0.020 0.022

RIGID POLYISOCYANDRATE Cellular, foil-faced glass fibre reinforced, Refrigerant 11 exp

120

POLYURETHANE Refrigerant 11 exp (unfaced)

100

RUBBER, Rigid Foamed

70

72

0.029 0.030 0.032 0.033

80

320

0.040 0.043 0.045 0.048

With colloidal clay binder

980

384-480

0.071 0.079 0.088 0.105 0.122

With hydraulic setting binder

650

480-460

0.108 0.115 0.122 0.137

24.0-40.0 0.023 0.024 0.026 0.026 0.026 0.024 0.023 0.023 0.024

VEGETABLE & ANIMAL FIBRE Wool felt (pipe insulation) INSULATING CEMENTS MINERAL FIBRE (Rock, slag or glass)

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TABLE 5 (Thermal conductivity (k) of industrial insulation ± Continued) Form Material Composition

Accepted Typical Max Density Temp for (kg/m3) Use, oC

Typical Conductivity k at Mean Temp oC 73.3 59.4 45.6 31.7 17.8 3.9 10.0 23.9 37.8 93.3 148.9 260.0 371.1 482.2

LOOSE FILL Cellulose insulation (milled pulverised paper of wood pulp) Mineral fibre, slag, rock or glass Perlite (expanded) Silica aerogel Vermiculite (expanded)

40.0-48.0 0.037 0.039 0.042

32.0-80.0 48.0-80.0 122

0.027 0.030 0.033 0.036 0.037 0.040 0.045 0.032 0.035 0.036 0.039 0.040 0.043 0.045 0.048 0.050

112-131

0.019 0.020 0.022 0.022 0.023 0.024 0.026

64-96

0.056 0.058 0.060 0.063 0.065 0.068 0.071 0.049 0.050 0.056 0.058 0.060 0.063 0.066

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Basic types of insulation ± selected properties TABLE 6 TYPE

FORM

TEMPERATURE RANGE

k-FACTOR *

NOTES

Calcium Silicate

Pipe Covering Block Segments

Up to 982oC (1800oF)

.066 at 150oC .45 at 300oF

Good mechanical abuse characteristics, non-combustible. Some are water absorbent.

Cellular Glass

Pipe Covering Block Segments

267oC to 482oC ( 450oF to 900oF)

.077 to 150oC .53 at 300oF

Good strength, water and vapour resistant, non-combustible. Poor abrasion resistance.

Glass Fibre

Pipe Covering Board

to 455oC (850oF)

.035 at 24oC .24 at 75oF 0.050 at 150oC

Blanket

to 510oC (950oF)

.35 at 300oF varies see manuf. data

Properties variable. Good handling and workability. May be water absorbent. Some are non-combustible.

Pipe Covering

to 870oC (1600oF)

.035 at 24oC .24 at 75oF .061 at 150oC

Mineral Fibre

Non-combustible, good workability water absorbent.

.42 at 300oF conductivity varies with density

Board

Ceramic Fibre

Blanket or Board

to 1760oC (3200oF)

.30 at 93oC (200oF)

Temperature ranges varies with manufacturer, style and type.

Cements

Hydraulic setting cement

to 650oC (1200oF)

1.75 at 315oC (600oF)

High temperature mineral wool

to 1040oC (1900oF)

.69 at 315oC (600oF)

Pointing and finishing cement

to 760oC (1400oF)

.55 at 93oC (200oF)

One coat application ± Insulating and finishing. Slow drying, rough texture ± filling and insulating. Used over basic insulation ± smooth finish, usually 3.175 mm (1/ 8") to 6.35 mm (1/ 4") thick application.

(Mineral or Vermiculite)

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Protective coverings and finishes TABLE 7 WEATHER BARRIERS TYPE

COMPOSITION

FASTENERS

NOTES

JACKETS:

1. Films laminated to felts or foil

Contact adhesives and/or tape

Corrosion resistant bacteria and mildew resistant

2. Stainless steel (various alloys ± available with factory-applied moisture barrier)

Corrosion resistant bands, screws or rivets

Excellent mechanical strength, corrosion, mildew and bacteria resistant

3. Galvanised Steel (coated and with factory-applied moisture barrier)

Corrosion resistant bands, screws or rivets

Good mechanical strength

4. Aluminium alloys (usually with factory-applied moisture barrier)

Corrosion resistant bands, screws or rivets

Good mechanical strength, good workability

5. Polyvinyl Chloride (PVC)

Mechanical fasteners, adhesive or matching tape

May require protection from ultra-violet radiation.

6. High Impact Plastic (ABS)

ABS welding adhesive or matching tape

Resists chemicals and bacteria

7. Roofing felt

Bands or wire

Water base, a breather mastic

1. Asphalt emulsion

Apply with reinforcing mesh

Solvent base, also a vapour barrier

2. Asphalt cut-back

Apply with reinforcing mesh

Tough, resilient film

3. Resin emulsion

Apply with reinforcing mesh

Tough, resilient film

4. Polyvinyl acetate

Apply with reinforcing mesh

Tough, resilient film

5. Acrylic

Apply with reinforcing mesh

Tough, resilient film

MASTICS:

Covering shall not be termed a weather barrier unless its joints and overlap are adequate to prevent the entry of rainwater.

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Vapour retarders TABLE 8 TYPE

COMPOSITION

NOTES

JACKETS:

1. Foil Scrim Laminate

Seal joints. Mechanical strength is less than metal or plastic. Generally for indoor applications.

2. Metal Jacketing

Seal joints. Mechanical strength is good.

3. Polyvinyl Chloride (PVC)

Seal with compatible adhesive and/or tape.

4. High Impact Plastic (ABS)

Seal with welding adhesive.

5. Film Laminate

Seal with contact adhesive and/or tape

1. Asphalt cut-back

Apply with reinforcing mesh. Combustible.

2. Resins ± advent type

Brush or spray application.

3. Elastomeric Polymer

Apply with reinforcing mesh. Combustible.

MASTICS:

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Energy Content of Some Fuels TABLE 9 Fuel

Energy content blast furnace gas

3.1

MJ / cubic metre

coal: bituminous

25

MJ / kilogram

coke oven gas

17.3

gasworks gas

18

MJ / cubic metre

LPG (liquid)

27

MJ / litre

natural gas

33-42

oil

42

MJ / kilogram

paraffin

35

MJ / litre

SASOL gas: hydrogen rich

18

MJ / cubic metre

SASOL gas: methane rich

33-36

MJ / cubic metre

wood, air dried

17

67

MJ/cubic metre

MJ / cubic metre

MJ / kilogram

SOURCES OF FURTHER INFORMATION For the latest news in energy efficiency technology: ªEnergy Management Newsº is a free newsletter issued by the ERI, which contains information on the latest developments in energy efficiency in Southern Africa and details of forthcoming energy efficiency events. Copies can be obtained from: The Energy Research Institute Department of Mechanical Engineering University of Cape Town Rondebosch 7700 Cape Town South Africa Tel No: (+27 21) 650 3892 Fax No: (+27 21) 686 4838 Email: [email protected]

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