NBS

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REFERENCE

NBSIR 85-3146

AlllOb 0 5 3 b 5 3

An Assessment of Needs for New

Thermal Reference Materials

Brian Rennex

U.S. DEPARTMENT OF COMMERCE

National Bureau of Standards

National Engineering Laboratory

Center for Building Technology

Gaithersburg, MD 20899

April 1985

Prepared for: U.S. Department of Energy

nr

/N*fice of Building Energy ^

search and Development

100 ishington, DC 20585

. U56

85-3146

1985

NBSIR 85-3146

AN ASSESSMENT OF NEEDS FOR NEW

THERMAL REFERENCE MATERIALS

Brian Rennex

U S. DEPARTMENT OF COMMERCE

National Bureau of Standards

National Engineering Laboratory

Center for Building Technology

Gaithersburg, MD 20899

April 1985

Prepared for: U.S. Department of Energy

Office of Building Energy

Research and Development

Washington, DC 20585

U.S. DEPARTMENT OF COMMERCE, Malcolm Baldrige, Secretary

NATIONAL BUREAU OF STANDARDS. Ernest Ambler. Director

PREFACE

This report is one of a series documenting NBS research and analysis efforts to

support the Department of Energy/National Bureau of Standards' Measurements

Technology Program. The work reported in this document was sponsored by

Department of Energy through DOE/NBS Task Order A008 under Interagency Agreement

No. DE-AI01-76PR06010.

PRODUCT DISCLAIMER

Because of the nature of this report, to assess the kinds of products that are

actually in use, there is an occasional use of a trade name or a manufacturer's

name. This in no way represents an endorsement of a particular product or manufacturer. The thermal parameter values for the various insulating materials

were obtained from the literature or from researchers. These values were not

based on experimental research at NBS.

iii
ABSTRACT

Thermal insulation specimens are required by users to calibrate their heat

transfer apparatuses. This report assesses the need for additional

calibration specimens to cover a wider range of test conditions and materials.

It examines two major sources of measurement error related to the use of calibration specimens. The first is due to the lack of uniformity over a specimen

area and the second is due to sytematic apparatus errors which vary with the

values of specimen mean temperature and thermal conductivity. Possible

solutions to these problems are given, based on information obtained from

users in universities, industry, and government laboratories. These include

recommendations to provide calibration specimens over a wide range of values

of specimen temperature and thermal conductivity.

Key Words: apparent thermal conductivity; calibration; guarded hot plate;

heat flow meter; standard reference material; thermal insulation;

thermal properties; thermal resistance.

iv
TABLE OF CONTENTS

Page

PREFACE iii

ABSTRACT iv

LIST OF FIGURES vi

LIST OF TABLES vi

LIST OF APPENDICES vii

ACKNOWLEDGMENTS viii

EXECUTIVE SUMMARY 1

1. INTRODUCTION 2

1 . 1 Background 2 1.2 Objectives

1.3 Scope 3

1.4 Organization 3

2. CALIBRATION PROCEDURE AND CALIBRATION SPECIMENS 3

2.1 Calibration Procedure 3 2.2 Calibration Errors 4

2.3 Material- Variability Errors 6

2.4 Calibration-Specimen Criteria 6

3. AREAS OF NEED FOR CALIBRATION SPECIMENS 8

3.1 Introduction . . 3.2 Activity 9

3.3 Areas of Need for Building-Temperature Insulation Materials . . 10

3.4 Areas of Need for Industrial High-Temperature Insulations ... 11

3.5 Areas of Need for Higher Thermal-Conductivity Materials .... 12

3.6 Areas of Need for Other Thermal Properties 12

4. DISCUSSION OF RECOMMENDED CALIBRATION-SPECIMEN MATERIALS 13

4.1 Introduction 13

4.2 Recommended Calibration-Specimen Materials for Building

Insulations 15

4.3 Recommended Calibration-Specimen Materials at High Temperature.

4.4 Recommended Calibration-Specimen Materials at High Thermal

Conductivity and at Building Temperatures 21

4.5 Recommendations for Other Thermal Properties

4.6 Summary Comments on Recommendations 22

REFERENCES 2 3

v
LIST OF FIGURES

Page

Figure 1 - (X,T) Activity by Material for Building-Temperature

Insulation Manufacturers A-l

Figure 2 - (X,T) Activity by Material for Industrial Insulation

Manufacturers (Medium-Temperature Range) A-2

Figure 3 - (X,T) Activity by Material for Industrial Insulation

Manufacturers (High-Temperature Range) A-3

Figure 4 - (X,T) Activity by Material for Commercial Laboratories .... A-4

Figure 5 - (X,T) Activity by Material for Universities A-5

Figure 6 - (X,T) Activity by Material for Federal Laboratories A-6

Figure 7 - Sectioned Heat-Flux-Transducer Device A7

LIST OF TABLES

Page

Table 1 - Candidates for Standard Reference Material Recommended

by 1978 ASTM Study A-8

Table 2 - Useful Information for Reference Materials A-9

Table 3 - Suggested Thermal Conductivity Value Calibration Points for

Building Insulation A-10

Table 4 - Suggested Materials and Thermal Conductivity Values at

High-Temperatures A-ll

Table 5 - Suggested Materials at High Thermal Conductivity Values at

Building Temperatures A-l

2

vi
LIST OF APPENDICES

Page

Appendix 1 - User Interests and Test Activity 1-1

Appendix 2 - Interview Data 2-1

Appendix 3 - Attendees at Assessment Issues Work Session Held at the

National Bureau of Standards on July 13, 1984 3-1

Appendix 4 - Alphabetical List of Insulating Materials in Appendix 2 . . 4-1

Appendix 5 - List of Insulating Materials in Appendix 2

by Decreasing Thermal Conductivity Value 5-1

Appendix 6 - List of Members of Insulation Manufacturers’

Associations 7-1

vii
ACKNOWLEDGEMENTS

The author expresses appreciation to the Department of Energy whose sponsorship

made this effort possible. Programatic and technical coordination was provided

by Bill Gerken, Program Manager, Materials Program, Building Systems Division,

Office of Energy R & D, Department of Energy, and Dr. David McElroy of the Oak

Ridge National Laboratory. The author wishes to thank Carmen Gracia for her

help in gathering and presenting data and Frank Powell for his recognition of

the importance of this subject and his help in initiating this task. The author

extends his thanks to Tom Faison, Frank Powell, Dr. Walter Rossiter, Jim Heldenbrand

and Jeff Horlick for their helpful review comments. He also thanks the thermal

measurement users who provided technical information and those users listed in

appendix 3 who participated in a brainstorming session on the issues of thermal

calibration.

viii
EXECUTIVE SUMMARY

Thermal insulation specimens of known thermal resistance have historically

been used to calibrate heat transfer apparatuses. This report assesses the

need for new calibration specimens. It examines two major sources of significant measurement error related to the use of calibration specimens. The

first is due to the lack of uniformity over a specimen area, and the second

is due to systematic apparatus errors which vary with the values of specimen

mean temperature and thermal conductivity. The magnitude of these errors can

be several percent in typical tests of building insulations, and it can be

greater at more extreme test conditions. Possible solutions to these problems

are given, based on information obtained from users in universities, industry,

and government laboratories.

Issues related to individual calibration specimens for use in industry or re- search calibration programs are examined in-depth. This examination includes

a discussion of the calibration procedure. A frame of reference is developed

which includes the concepts of calibration curves, extrapolation errors, and

material-variablity errors. In addition, there is a discussion of criteria

for calibration-specimen materials.

Representatives of the various groups who use calibration specimens were interviewed to assess their needs and to search for new developments in materials.

The interview information is presented along with pertinent data on insulating

materials. There is considerable overlap of the needs of the different categories of users. Based on the information gathered and on technical considerations, recommendations are made for short-term and long-term solutions to the

reported calibration problems.

Short-term recommendations are to (1) develop calibration-specimen materials

to cover the apparent thermal conductivity ranges corresponding to loose-fill,

cellulosic material and to fluorocarbon-blown foams, using existing materials

and a sectored heat-flux-transducer device, (2) continue work on the first

calibration-specimen material for industrial (high-temperature) insulation

material, and (3) extend the temperature range of existing standard reference

materials using existing National Bureau of Standards apparatuses.

Long-term recommendations are to (1) look for ways to obtain very uniform speci- mens in the building-insulation regime (using layered or loose-fill composite

"custom-made" specimens), (2) establish two other high-temperature calibrationspecimen materials (at higher and lower thermal conductivity values), (3) make

available calibration specimens in the high thermal conductivity value regime

depending on future demand, and (4) explore the development of materials for

calibration with reference to other thermal properties.

1
1. INTRODUCTION

1.1 Background

Accurate measurement of the thermal resistance of insulation and building

materials is a matter of national concern. Procedures to ensure such accuracy

involve the use of calibration specimens, such as those provided by the National

Bureau of Standards (NBS). To achieve sufficient accuracy, these specimens must

be available over a wide range of test conditions. This is not the case today.

This report recognizes the valuable earlier work [1] published by an ASTM

Working Group in 1978. That report identified many issues related to the use

of reference materials for insulation measurement comparisons. It gave information on many candidate materials, and this information is summarized in

Table 1. In addition, it recommended (1) a search for new Standard Reference

Materials (SRM’s), and (2) the development of a long-range priority scheme.

This assessment report begins the implementation of these two recommendations.

This report addresses the question of what is necessary to maintain an effective

national calibration program for thermal tests. It maintains that such a program should serve the entire user community, which includes manufacturers,

commercial testing laboratories, government laboratories, and university

researchers. A viable national calibration program must consist of accurate

apparatuses, appropriate test methods, and calibration specimens available

over a sufficient range of test and material parameters.

Often, calibration values vary with test parameters such as specimen mean

temperature, apparent thermal conductivity (or thermal resistance), and

thickness. For example, if a Standards Laboratory provides a calibration

point at one temperature, but the user laboratory tests specimens at a very

different temperature, then significant errors in calibration may result.

This kind of calibration error is referred to as an extrapolation error in

this report. One way to minimize extrapolation errors would be to have

calibration points available over the needed range of apparent thermal

conductivity and temperature.

1.2 Objectives

This report has three objectives. The first is to give a brief explanation of

the calibration procedure to establish a frame of reference for subsequent

discussion and to explain why calibration specimens are needed over a wide

range of test parameters to reduce the extrapolation errors just mentioned.

The second is to assess the need for new calibration materials which could be

tested over the just-mentioned ranges of need. This assessment is based on information obtained from the heat-transfer test community. The third objective

is to propose solutions in terms of new calibration materials and procedures

based on this information obtained from users and based on an analysis of the

calibration procedure.

2
1.3 Scope

The analysis and the recommendations in this report are based on experience

obtained at NBS, on a survey of users, and on results reported in literature.

An attempt was made to contact a sufficient number of users and potential

users to achieve a good representation of the calibration needs. Some information that is important for the analyses herein is not reported in the literature,

and must be documented as personal communication. Please note the product

disclaimer on page iii.

This report is intended for potential users of heat-transfer calibration

specimens, interested researchers, and government policy makers. This covers

a wide spectrum of measurement expertise ranging from a quality control technician who just measures one kind of material to a researcher who develops

state-of-the-art calibration procedures. Researchers who are very familiar

with thermal resistance calibration may wish to skim section 2 for definitions,

while a newcomer to the field may find it useful to read it carefully, along

with the references. The users of thermal conductivity calibration specimens

are categorized as manufacturers, university researchers, commercial testing

laboratories, and government laboratories.

The discussion of calibration material is limited to insulating materials, as opposed to metals, in the thermal conductivity range between 0.015 to 5 W/m*K

(0.10 to 35 Btu»in/f

t

2 »hr • °F) , and to testing conditions between -200 to 1200°C

(-392 to 2192°F). The emphasis, however, is on building and industrial insulation

materials. Also, the emphasis is on the measurement of thermal resistance,

although other thermal properties are mentioned.

This report is intended to serve as an reference document for both technical

and policy issues and to provide a quick current overview of the field of insulation

thermal conductivity measurement.

1.4 Organization

Section 2 provides background on the aspects of calibration procedure related

to the use of calibration specimens. Section 3 discusses the needs for calibration specimens based on a survey reported in Appendices 1 and 2. Appendix 2 contains the more detailed description of this survey. Section 4 makes

recommendations for new calibration specimens and procedures, and it discusses

trade offs associated with the various solutions.

2. CALIBRATION PROCEDURE AND THE USE OF CALIBRATION SPECIMENS

2.1 Calibration Procedure

There are many kinds of apparatuses which measure heat transfer through

insulation material. Some of these are absolute, such as the guarded hot

plate [2], while others are relative, such as the heat flow meter (3).

3
Relative apparatuses always require calibration specimens as an integral part

of the test procedure. Absolute apparatuses do not require calibration specimens, but it is often prudent to use such specimens to corroborate the absolute

measurement values.

The basic idea of a calibration is the following. A calibration specimen is

measured by a reference laboratory such as NBS. The important physical

parameters for thermal measurements are measured and reported. Values are reported for thermal resistance (R-value), the specimen thickness, specimen

mean temperature, and the apparent thermal conductivity value (A-value).

Next, this same specimen is measured in the user's apparatus. If this is an absolute apparatus, such as a guarded hot plate (GHP), the user's value is

compared with the calibration value. If it is a relative device, such as a heat flow meter (HFM) apparatus, the calibration values are used to determine

a calibration factor which in turn is used to determine the thermal resistance

values of unknown test specimens. The calculation procedure is explained in

reference [4],

2.2 Calibration Errors

Significant systematic errors are possible in many thermal measurements.

Rather than undertake an extensive effort to reduce systematic errors, a user

can simply calibrate it using a material which has been measured in a highly

accurate apparatus. A ratio is made between data taken with the calibration

specimen in place, and data taken with an unknown specimen in place. To a large extent the systematic errors cancel out, and the researcher achieves a significantly improved accuracy [4-6]

.

If the calibration factors were constant over the entire range of test

conditions, then the calibration process would be simple. One would measure

the calibration factor under the most convenient test conditions, and use that

value for all test conditions and materials. However, information obtained in

interviews with users and in research at NBS [7] indicates that the calibration

factor often changes significantly depending on the apparatus and the test

conditions. Reference [8] documents variations in calibration factors in the

form of personal communications from some users. Variations of 1-4 percent were noted with a change from high-density to low-density building insulation.

Changes of 2-4 percent were typical as the test thickness varied from 25 to

152 mm ( 1 to 6 in); however, changes as high as 8 percent were mentioned.

For the subsequent discussion it is important to understand how significant

measurement errors can arise when calibration values cover only a limited

range of test conditions, as compared to the user’s required range. The

following parameters are measured in a heat-transfer test: the heat flux,

the specimen thickness, and the specimen surface temperatures. There are systematic errors in these parameters due to problems such as heat leaks.

These are commonly referred to as edge effects, gap or guard errors, or flanking loss. The calibration factor provides, in essence, a combined correction

for all of these systematic errors.

4
When the test conditions change, the following two things can occur. First,

the actual X-value can change; and, second, systematic errors can change.

This means that the calibration factor should be changed, which requires another

set of calibration values to cover the new and different test conditions.

The error that results when the calibration factor is not properly changed is

referred to here as an extrapolation error .

Test parameters that cause the calibration factor to vary are referred to here

as calibration-curve parameters . These include (1) the specimen mean temperature,

because both the specimen X-value and the systematic errors vary with temperature, and (2) the specimen thickness and X-value, because the systematic errors

such as edge error depend on these two properties.

Other variables may act as calibration-curve parameters for certain materials

or test conditions. The most important of these are the condition of the surface (for example, the contact resistance between a specimen and an apparatus

plate), the plate emittance, the pressure on the specimen surface, the atmospheric pressure and relative humidity, the specimen moisture content, the

specimen age, and the anisotropy of X-value.

One solution to the problem of extrapolation errors is to develop calibration

curves . The idea would be to determine the calibration factor for several

values of a calibration-curve parameter, such as the temperature. These values

would be chosen to cover the range of user needs. The user could then rely on techniques of interpolation to obtain a sufficiently accurate calibration factor.

For a calibration laboratory, the picture could be very complicated, because

there are usually two (temperature and X-value) and sometimes five (also

specimen thickness, atmospheric pressure, and humidity) calibration-curve

parameters. Thus, it is necessary to look closely at the user's needs to

develop a test scheme that does not require an inordinate number of test points.

An opinion currently held by many heat-transfer researchers is that the sources

of calibration error are so poorly understood that a calibration specimen must

be identical, in terms of material, with the specimens to be tested by the user. This is considered to be the safest course of action to avoid extrapolation

errors that might depend on the material. The problem with this solution is

that it could require an inordinate number of calibration materials, some of

which would not satisfy a calibration-specimen criteria.

Consider an alternative hypothesis, that a calibration specimen with the same calibration-curve parameter values as those of a test specimen, will provide

the correct calibration factor value, even though it is composed of a different

type of material. Unfortunately, there has been very little experimental

research to validate this hypothesis. Rather, the argument in its support is

theoretical. It states that the apparatus systematic error should depend

primarily on the calibration-curve parameters, and only negligibly on other

material parameters, such as anisotropy of X-value or density.

5
It would be desirable to pursue research on this issue for the following reason.

If the just-mentioned hypothesis were true, then a few materials could be used

to satisfy calibration needs for a broader grouping of test materials. The

advantages to a calibration laboratory could be that fewer materials would have

to be investigated or relatively more uniform or durable materials might be

used for calibration specimens.

The idea of calibration curves leads to the central theme of this report. To

develop such curves one must have: (1) the capability to make measurements

over a wide range of temperature and X-value, and (2) appropriate specimen

materials. These two points will be addressed more fully in the course of

this report.

2.3 Material-Variability Error

The other significant source of calibration error, in addition to the

extrapolation error just discussed, is the material-variability error. This

results from two factors: (1) most insulation material can be highly variable

in thermal resistance from one part of the specimen surface to another (2 to

10 percent), and (2) the measured area of the specimen (the metered area)

varies for different apparatuses. Thus, a calibration error may result because

the average thermal resistance over the user’s metered area may be different

from that measured over the metered area of the calibration laboratory. This error can be as large as 3 percent [9]. Thus, even if the apparatus of the user and the calibration laboratory are very accurate, there may still be a significant calibration error, due to material variability. Two suggestions

are made to minimize this problem. The first is to obtain or fabricate more

uniform insulation material, and the second is for the calibration laboratory

to develop a capability to vary the measuring area of the calibration apparatus.

The latter solution would provide the user with a calibration value corresponding

to the user's metered area.

2.4 Calibration-Specimen Criteria

There are a number of criteria and considerations for the choice of a calibration-specimen material. The most important of these pertain directly

to the measurement of apparent thermal conductivity or thermal resistance.

Characteristics (e.g. specific heat or radiative properties) which do not

apply directly to the determination of the X-value should be considered, for

two reasons. First, it may be convenient to use the same specimen for calibration of several properties, such as thermal resistance, thermal diffusivlty,

and specific heat. Second, a calibration in a particular application could

lead to unknown systematic errors if all relevant physical properties are not

well understood. For example, suppose that a material is stable at building

temperatures for steady-state thermal resistance measurements, but unstable

at higher temperatures for specific heat measurements. Then, an application

involving a transient measurement of thermal conductivity would give an incorrect result. The point is that, if the specific heat were incorrectly

assumed to be constant, the user would have unwarranted confidence in the results.

6
Reference [1] lists the following considerations in the choice of a calibration-specimen material.

1 . Range of properties for each material with respect to dimensional stability, density, and thermal properties.

2. Limits on allowable test temperatures and thermal exposures.

3. Probable reproduciblity and accuracy obtainable with general materials

and what might be expected for higher-level materials.

4. Ease of handling and durability of each material since this is an expected

use condition.

Table 2 gives a list of information and properties which could be of use in

the choice of calibration-specimen material. This is taken from table 3 of

reference [1]. The most important properties, including some from table 2, are discussed below.

STABILITY - Dimensional changes such as contraction, expansion, or warping due

to temperature or humidity changes or aging must be considered. Internal

structural changes due to temperature cycling, compression, or chemical reactions with the environment might change the thermal resistance even when the

specimen appearance does not change. In the case of closed-cell material

containing gases such as fluorocarbons, the diffusion of these gases into and

out of the specimen can cause measurable differences in thermal resistance

over periods of months or years. It is important to know the physical properties listed in table 2, not only as a function of temperature, but also as a function of humidity and atmospheric pressure, and possibly as a function of

the history of these conditions. To achieve good repeatability, it may be

necessary to define specific conditioning procedures, such as baking at a particular temperature and relative humidity to obtain a particular moisture

content.

DURABILITY - This refers to the resistance to changes in a specimen due to

wear, cracking, or deformation which could result in a change in thermal

resistance. Also, it should be possible to achieve flat, smooth surfaces in

the specimen fabrication. A goal would be for a specimen to last on the order

of 20 years.

RESILIENCY - In the case of compressible specimens, resiliency is required to

prevent air gaps between the specimen and the test plates. Also, a resilient

specimen would be more likely to be physically stable as environmental changes

occur.

There is often a trade off between durability and compressibility. Specimens

which are compressible near the surface are desirable because they conform to

the shape of the apparatus plates, and this prevents air gaps. On the other

hand, compressible material can be less durable because the surface material

can wear off. One solution might be to cover a compressible surface with a durable protective coating. But then research would be necessary to determine

7
whether a calibration error might result.

UNIFORMITY - This refers to the X-value, which in turn may depend on density

and thickness. The uniformity can refer to several kinds of comparisons. One

comparison is between different areas on the same specimen; others are among

specimens within a production lot, among lots produced in the same period, and

among lots produced over the years. The importance of a particular kind of

uniformity depends on the strategy for production of calibration specimens.

For example, if each specimen is measured, the uniformity over the specimen

area would be more important than the uniformity among specimens.

THERMAL DIFFUSIVITY - This property may itself be required for calibration,

or it may affect a measurement of thermal resistance when the measurement is

made in a transient mode. It depends on the A-value, the specific heat, and

the density. It is important to know these properties for various test

conditions.

ISOTROPY - The ratio of A-values in the directions parallel and perpendicular

to the specimen surface is important because the apparatus lateral heat flow,

and hence the systematic error, depend on this. Thus, research would be re- quired to demonstrate whether an isotropic material can be used to calibrate

for anisotropic materials.

RADIATION PROPERTIES - In the case where there is a significant proportion of

heat transfer via the radiative mode, it may be necessary to understand such

properties as transmittance and extinction coefficients to avoid error in some applications. For example, the edge effects in an apparatus may depend

on these.

Other considerations are safety, health (toxicity), and temperature limits.

With respect to these limits, if an industrial insulation were to meet the

calibration-specimen criteria over a wide range of temperature, then research

on a single material might suffice to cover that range; whereas the alternative may require research on several materials. Finally, there are practical

considerations of cost, availability, size, and demand. These criteria must

be taken into consideration in both the research and the eventual choice of

calibration-specimen materials.

3. AREAS OF NEED FOR CALIBRATION SPECIMENS

3.1 Introduction

The need for calibration specimens depends on: (1) the activity of the various

categories of the user community, (2) the current availability of calibration

specimens in that particular range of calibration-curve parameters, and

(3) the self-sufficiency of that particular category of users — in terms of

their capability to make accurate absolute thermal measurements. Another

consideration is that there are distinct kinds of needs. For example, in a

i 1,
commercial application an absolute accuracy of 2 percent might suffice, whereas

a university researcher might desire an accuracy of 0.2 percent. The relative

importance given to the various kinds of needs will determine the priorities

for the development of new calibration specimens.

3.2 Activity

A survey was made to determine the current activity, in terms of insulation

material produced and tested, by the various parts of the thermal testing

community. For the most part this survey was made by telephone for expediency.

An overview of the interview information is given in Appendix 1, and a more

detailed account is given in Appendix 2.

There were several reasons to present a representative picture of testing

activity. Good data on the activity of all parts of the thermal testing

community is necessary to develop a calibration program tailored to the needs

of the user community. Next, NBS sought to learn about new products or ideas,

which might lend themselves to improved calibration specimens. The telephone

conversations led to another benefit - of two-way communication with users who

may not have thought in terms of utilizing new calibration specimens.

These same goals were pursued in a work session at NBS attended by representatives of the user groups (see Appendix 3). The ideas contained in this report were reviewed by the participants, and their comments were taken into consideration in the conclusions of this report.

An additional mechanism exists to determine user needs for calibration specimens

in the form of the National Conference of Standards Laboratories (NCSL), the

membership of which includes representatives from the National Bureau of

Standards (NBS) and from the various user groups. Reference [10] contains

preliminary information on users needs for the measurement of thermal conductivity. The information presented in appendix 2 will serve as a data resource

for future NCSL activities.

The user community is categorized for this report as follows: (1) manufacturers

of insulating products, (2) commercial thermal testing laboratories, (3) university

researchers, and (4) federal laboratories [11]. The manufacturers are subdivided

into producers of building and industrial insulation products and into producers

of higher thermal conductivity materials such as plastics, rubbers, glass, wood,

cement, ceramics, epoxies, and composites.

The activity in terms of thermal testing of insulation materials is presented

according to categories of user-groups, to enable policy makers to arrive it their own priority scheme for the research necessary to refine their raeasur'-m.-nt capability. Here, one viewpoint will be presented as to what that priority

scheme might be, along with a discussion of the trade-offs. It is entirely

possible, however, that a policy maker with a different set of priority values

might come up with a different priority scheme, and the information in this

9
report is intended to aid that process.

With reference to the discussion in section 2, the areas of need will be grouped

according to the most significant calibration-curve parameters, namely the A-value

and specimen temperature. The discussion will begin with building-temperature

insulation material and then proceed to higher temperature and thermal

conductivity ranges.

3.3 Areas of Need for Building-Temperature Insulation Materials

Table 3 presents conclusions on the A-values where there is a clear need for

calibration specimens. These conclusions are based on information summarized

in Appendix 1 and detailed in Appendix 2. Referring to Table 3, there is a distinct need for calibration standards at the following A-values: 0.016,

0.023, 0.033, 0.040, and 0.046 W/m-K (0.11, 0.16, 0.23, 0.28, and 0.32

Btu*in/f X?- ‘hr *F - the A-values in English units will follow in parentheses).

The generic products for these A-values are also given in table 3. Calibration

standards exist for the 0.033 W/m*K (0.23) point corresponding to high-density,

glass-fiber material. These are available from the NBS Office of Standard

Reference Material under the designation of 1450B. In addition, it is possible

to order transfer standards of low-density, glass-fiber insulation material

with a A-value of 0.046 W/m*K (0.32), from the NBS Thermal Insulation Group [12].

Considerable interest was expressed by the manufacturers of foam products to

have standards covering their range of interest, which is 0.016 W/m*K

(0.11) to 0.023 W/m*K (0.16). The former point corresponds to non-aged,

fluorocarbon-blown products and to an aged phenolic foam, and the latter point

corresponds to aged fluorocarbon-blown foam products. Since this represents

approximately a 50 percent range difference for the A-value, two A-value

points are recommended for calibration standards. The range of thickness for

testing is between 13 and 100 mm (0.5 and 4 in). It is recommended that there

be specimens available at thickenesses of 25, 50, and 100 mm (1, 2, and 4 in).

One reason for the recommendation of standards at the greater thickness is

that the interviews revealed some evidence of a dependence of the apparent

thermal conductivity on thickness for the low-density foam products.

An interest was expressed by industry for a calibration standard in the 0.040

W/m»K (0.28) range, which corresponds to the A-value for several batt and

loose-fill products (both cellulosic and mineral-fiber). A number of cellulose

and mineral-fiber commercial test laboratories and manufacturing laboratories

test material at this A-value at a thickness between 100 and 150 mm (4 and 6

in). It was reported that the calibration factors for different kinds of

calibration specimens did not give consistent results at the A-value of 0.04

W/m*K (0.28) [7]. It would not be practical to interpolate between the low

density calibration standard and the high-density standard points, because the

high-density point uses a 25 mm (1 in) specimen. It is not recommended to stack

several of these specimens to achieve the desired thicknesses — because it would

be necessary to purchase many additional calibration specimens, because the

10
test times would be prohibitively long, because the error due to stacking is

unknown, and because the error due to long-term drifts with such a relatively

high-density specimen may be significant. It would be more satisfactory to

have a single calibration specimen with a lower density, corresponding to that

of the loose-filled material itself. The benefit would be a considerable

reduction of test times.

Regarding the point at 0.065 W/m»K (0.45), there is some test activity, but not

nearly as much as that in the other X regions. There was no demand on the

part of interviewed users for a calibration specimen here.

At cryogenic temperatures down to liquid nitrogen temperature no current activity

on the part of manufacturers was found. In the past there was some interest,

in regard to the storage of liquified gas. There has been some characterization

of the low-density and high-density, glass-fiber standards available from

NBS-Boulder Laboratories.

In summary, calibration points are recommended at X-values of 0.040 W/m»K

(0.28) corresponding to loose-fill products, and of 0.016 and 0.023 W/m*K (0.11

and 0.16) corresponding to the non-aged and aged fluorocarbon-blown foam products.

3.4 Areas of Need for Industrial High-Temperature Insulations

Referring to Table 4 and section 1.3 of Appendix 1, four distinct regions

of X-value were chosen to make it easier to refer to a particular area in

Figure 3. Beginning with the lowest X-value, the first region corresponds

to the Min-K product which has a X-value of about 0.043 W/m«K (0.30) over the indicated high-temperature range. A product made in England

called Microtherm has X-values comparable to Min-K. It would be useful to

have calibration specimens in this region to evaluate any change in

calibration factor between regions.

The second region corresponds to a class of materials which vary in X-value

from 0.058 to 0.115 W/m»K (0.4 to 0.8) over the temperature range from

24°C to 1000°C (75°F to 1832°F). This appears to be a region of considerable

activity and, hence, need. A representative material from this class of

insulations must be identified to serve as a calibration standard material.

There is an effort underway to measure an alumina-silica fiber material (see

the discussion of cera fiber in section 1.3.2 of Appendix 1), and this could

satisfy the short-term needs in this region.

The third region corresponds to brick refractories. These materials have

a X-value in the vicinity of 0.14 to 0.29 W/m*K (1.0 to 2.0). This

could be a third region for a calibration standard. Note that, for a particular

specimen, the X-value is fairly constant over the high-temperature range.

An additional fourth region could be that at about 2 W/m*K (14.0). This is

about an order of magnitude greater in X-value than region 3, and there

might be extrapolation problems if a separate calibration standard or calibration point were not available here. That is, the existence of calibration

11
specimens at the extremes of the ranges would aid in the estimation of

extrapolation errors. On the other hand, there seems to be considerably

less need at this higher A-value range relative to that indicated at the

lower ranges

.

3.5 Areas of Need for Higher Thermal Conductivity Materials

In the A-value range between 0.072 and 2.89 W/m*K (0.5 to 21.0), there are many

materials that are not used primarily for thermal insulation, but which have

some insulating value. With reference to figures 4 through 6 which are based

primarily on the interview data, these materials include rubbers, plastics,

epoxies, concrete, soils, moist insulation, wood, glass, volcanic rock, pyrex,

and pyro ceram. Perhaps because these materials are not produced primarily

for use as thermal insulations, the people contacted in appendix 2 did not

indicate as much interest in thermal conductivity standards in this high A-value

range, as in the low A-value range. On the other hand, various representatives

from each user group did mention having made measurements of A-value for

materials in this range. In addition, information received from a manufacturer

of heat-transfer apparatus (the Dynatech R & D Company mentioned in appendix

2) indicated that one out of four of the heat-transfer apparatuses sold were of

a design primarily intended for high A-value measurement.

With reference to building research in general, the following line of reasoning

suggests that perhaps there should be more interest in the measurement of high

A-value materials. There are many high A-value building components which

cause thermal bridging. In almost every case, handbook values are used to

estimate the A-value for these components (several thermophysical data sources

are listed in references [13-16]). The resulting errors are not well understood

and could be significant. This impacts the overall quality of building research

in that the modeling has become very sophisticated, but the accuracy of parameter

estimation has not improved correspondingly. Moreover, even if some specimens

of building components are measured, an important issue which is usually ignored

is the extent to which the values for a few specimens represent the average for

all of that component material in a building system. In other words, the

product variability could result in large and ignored errors. Even though

there is not a great deal of activity in measuring high A-value materials,

these arguments suggest that more accurate measurement in this range would

be beneficial.

3.6 Areas of Need for Other Thermal Properties

In order to properly explain the heat-transfer phenomena that exist in real

applications, it is necessary to know other thermal properties such as the

thermal diffusivity, the surface emittance, radiation absorption and scattering

cross sections, and thermal expansion. An interest was expressed in these

thermal properties, primarily by representatives of the federal laboratories

and by university researchers. Also, a suggestion was made to try to use

the same calibration standard material for the measurement of several different

12
thermal properties. With reference to appendix 2, there are a number of

laboratories which are involved in the measurement of the radiation scattering

properties of low-density insulation materials. It might be desirable to

extend the temperature range of these tests to higher temperatures where

radiation is the predominant heat-transfer mode.

4. DISCUSSION OF RECOMMENDED CALIBRATION-SPECIMEN MATERIALS

4.1 Introduction

In this section, candidate standard reference materials are suggested to meet

the needs discussed in section 3. Issues related to the choice of a standard

reference material will first be reviewed. The major sources of systematic

measurement error are the extrapolation errors and the material-variability

errors discussed in section 2. In order to minimize the extrapolation errors,

it is necessary to have calibration points which are as close as possible to

the test points for the unknown material to be measured or which bracket the

range of interest.

Once the applicable X-value and temperature ranges have been chosen, the most

difficult remaining problem is the non-uniformity of specimen material. There

several kinds of non-uniformity of importance to the development of calibration

materials. One kind is between product lots, another is among specimens within

a lot, and a third kind is between different sections of a specimen. An important

conclusion of the interview work summarized in appendices 1 and 2 is that

there is very little information on material uniformity. A possible reason

is that it is difficult and time consuming to measure material variability.

The little information that exists indicates that material-variability error

may be significantly large in calibration applications [7, 9, 17]. The reason

for this is that the producers' requirement for uniformity is probably quite

different from a calibrator's requirement.

It is desirable for the material-variability error to be less than or of the

order of the apparatus error. This would be the case, for example, if the

apparatus error were 0.7 percent and the material variability error were 0.3

percent. That is, the uniformity of the material would be sufficiently good

to ensure that the variation in X-value over the specimen area would be less

than 0.3 percent. Unfortunately, this kind of uniformity can not now be

realized, and non-uniformity is the factor responsible for overall calibration

uncertainty values of the order of 2 to 3 percent. These values could be less

than 1 percent if greater uniformity were achieved [4,9].

These comments on the importance of uniformity are most pertinent where the

measurement accuracy is the best. For example, in the building-temperature and

in the cryogenic temperature ranges, the apparatus uncertainties are smaller than

in the high-temperature and, perhaps, high X-value ranges. For example, It the

apparatus uncertainty were 0.5 percent and the material-variability uncertainty

were 2 percent, then uniformity would be an important issue. But, if the appamtu

13
error were 5 percent and the material variability were 2 percent, uniformity

would not be as important an issue.

There are two approaches for the identification and acquisition of calibration

specimen material. The usual approach is to locate the most uniform insulation

material that is produced and to use it without modification. The major

difficulty with this approach is the just-discussed problem with material

non-uniformity. An alternative approach would be to fabricate a specimen

which is different from the insulation material as produced, but which represents

a better solution in terms of uniformity, durability, and stability over time.

For example, a specimen might consist of layers of higher and lower thermal

conductivity material with an intermediate effective thermal conductivity.

This would be an improvement if the uniformity of the higher and lower

conductivity materials were better than that of any single material at the

intermediate value.

The hypothesis discussed at the end of section 2.2 is that the calibration factor

will not be in error if there is a match of calibration-curve parameters between

a custom-made calibration specimen and unknown test specimens. This hypothesis

is implicit in the following discussion of innovative calibration specimens.

There are good reasons, resulting from an analysis of the origin of systematic

apparatus errors, to expect that this hypothesis will prove to be true (refer

to the discussion in section 2). Even so, the hypothesis must be experimentally

validated.

The idea of custom-made calibration specimens leads to innovative solutions

such as layered or composite loose-fill materials or surface-sealed specimens.

The basic intent in the case of a composite specimen would be to use two materials, one of higher A-value and one of lower A-value, to fabricate calibration specimens which cover a range of A-values. The relative proportion

of materials would then determine the resultant A-value. This sort of a solution might have three advantages. First, the desired A-value within the

range could be achieved, and this would minimize extrapolation errors. Second,

a proper mixing might significantly reduce the errors of non-uniformity. And

finally, it might be possible to achieve a more economical solution, in that

one composite could serve as a standard for many kinds of material. This

would eliminate the time-consuming necessity of testing many different kinds

of materials to satisfy the entire range of calibration needs.

The solution for the entire calibration program must take into account the

various sources of error and criteria such as durability or stability in time.

This means that an order of magnitude should be associated with each of these

considerations. The solution will be the result of trade offs.

Another possible solution would be to develop a test method with a variable

metered area. NBS is currently evaluating a sectored heat-flux transducer

which is shown in figure 7. This device gives independent readouts for various

sectors or metered areas which correspond to typical metered areas in use in

14
this country. These include the following: 100 x 100 mm (4 x 4 in) square,

252 x 252 mm (10 x 10 in) square, 400 mm (16 in) diameter circular, and 457 x

457 mm (18 x 18 in) square. For a heat flux of 17.5 W/m^ and plate temperatures

of 38°C and 10°C, the outputs from the separate regions were, beginning with

the smallest and proceeding to the largest, 5.1 mV, 27.5 mV, 31.3 mV, and

37.2 mV. Note that the output for each succeeding larger section does not

include the area covered by the smaller sections within. The point here is

that the output should be large enough in comparison with the readout precision

( 0.001 mV), to determine the material variability to within a few one-hundredths

of one percent.

If this device proves effective, it could be used for a second, relative

measurement — after the absolute measurement on the 400 mm (16 in) diameter

circular metered area of the NBS-GHP apparatus. This second measurement would

yield the X-values of the other sectors relative to that which was absolutely

determined for the NBS metered-area sector. It would be necessary to calibrate

the sectored flux transducer in either a uniform heat flux or by doing a statistical study on a large number of non-uniform specimens. It would also be

necessary to determine the systematic errors due to lateral heat loss effects,

that would prevail in this kind of a secondary measurement. The precision of

the device must be sufficient to achieve a good determination of the uniformity,

but it remains to be seen whether or not systematic errors would prevent its use in calibration work. Also it would be preferable to have two such variablemeter-area devices, one on either side of the specimen, to determine the uniformity over the entire thickness of the specimen, rather than just on one side.

A screen-heater apparatus, developed at Oak Ridge National Laboratory would

also lend itself to making variable meter-area measurements [18,19]. This

possibility is due to the fact that the heat flux is constant over the surface

area and the determination of the relative X-values depends on the measurement

of the temperature difference. This measurement of temperature difference

could be accomplished by thermopiles which cover various metered areas of the

specimen. That is, a system of individual section thermopiles could accomplish

the desired result of a variable metered area.

A general approach implicit in the subsequent discussion of new calibration

specimen material is to (1) locate the most uniform material available and

(2) determine the actual X-value over the user metered area using the

sectored heat-flux-transducer device.

4.2 Recommended Calibration-Specimen Materials for Building Insulations

Short term

Short-term solutions for new calibration-specimen materials are addressed

first. These involve the first approach just discussed - to use existing

15
insulation materials for calibration specimens, since this requires less

development time. The long-term recommendations use the second approach - to

fabricate custom-made calibration specimens — and this requires more time for

research and development. The solutions that seem best in terms of simplicity

and speed will be discussed first. Alternative solutions are also mentioned

since research may demonstrate the inadvisability of an initial approach.

Referring to table 3, at a X-value of 0.040 W/m»K (0.28) the recommended

material is a glass-fiber product which has a density of about 24 kg/m3

(1.5 lb/ft 3). This would be tested at thicknesses between 100 and 150 mm

(4 and 6 in). One advantage of this material is that the density is low enough

to ensure reasonably short test times even though the thickness is relatively

large. That is, the time needed for a test to come to steady-state conditions

depends on the total specimen mass. Also, there is a history of the use of

glass-fiber material as calibration standards. The uniformity of X-value

over the specimen area is expected to be better than that of the lower-density

(9 kg/m3 or 0.6 lb/ft 3

) calibration specimens that have been tested in the

past by NBS. A third advantage is that durability would be somewhat better.

Material of this type is available from several manufacturers.

The procedure would be to buy a quantity of specimens. After several specimens

had been tested, a statistical evaluation would be made to determine the appropriate additional number of specimens to be tested. A number of ten has been

found to be appropriate in the past [7]. These specimens would then be measured

on the NBS-GHP apparatus, with the sectored heat-flux-transducer device, and on the NBS heat-flow-meter apparatus. In addition, ten specimens of loose-fill

glass-fiber material and ten specimens of loose-fill cellulose material

would be tested on the same three apparatuses. A comparison would then be made

of the calibration factors calculated with data from the three different kinds

of materials to determine any dependency on material type. This comparison

would take into account any X-value dependence for the calibration factor.

Another possibility is a layered specimen which would consist of a phenolic

foam with a low X-value on either side of a higher-density material. The

desired average X-value could be selected by having the appropriate thicknesses

for the three layers of material. The advantages of this approach could be

that the most uniform material available would be used, and the desired

resultant X-value could be closely approximated. It would be necessary to

evaluate the requirements of durability, compressibility and flatness for the

composite, and to find adhesives for bonding the layers that would retain

their properties over time. The manufacturer of the phenolic foam indicated

that the material is machinable, and therefore it should be possible to achieve

a flat specimen surface where contact is made with the apparatus plates. If

this layered composite were tried, then it would be necessary to compare the

results of this type of calibration specimen with the results mentioned in the

previous paragraph.

16
The next two areas of need (refer to Table 3) will be discussed together.

These correspond to X-values of 0.023 and 0.016 W/m»K (0.16 and 0.11). The

materials which need to be measured in this range are primarily the fluorocarbon-blown foams. These have unusually low X-values because the gas

conductivity in the fluorocarbon gas that fills the closed cells of these

materials is lower than the gas conductivity of air. When these materials are

first produced, the fluorocarbon content is high and the X-value is correspondingly low about 0.016 W/m«K (0.11); but the fluorocarbon diffuses out

through the cell walls and air diffuses in over a period of months or years.

The eventual X-value depends on the equilibrium mixture of these gases.

The X-value increases to values between 0.023 and 0.029 W/m»K (0.16 and

0.20). This diffusion process is referred to as aging.

The recommended calibration-specimen material is a phenolic foam which shows

promise of having a slow aging process with very little change from year to

year. Refer to item #10 of section 2.1.1 in appendix 2. Although it would be

preferable to use a material that does not age at all, the problem is one of

finding such a material in this range of X-value. A suitable trade off

might favor a material which ages sufficiently slowly to satisfy a certain

tolerance level, over a more stable material which has a significantly different

X-value.

Preliminary evidence indicated no measurable change in X-value of phenolic

foam over a period of three years. This suggests that the material might be

suitable as a calibration-specimen material. The first item of research

would be to investigate this question further. In the event that there is a small but non-negligible change over a period of several years, it might be

acceptable to remeasure these specimens periodically. Or, specimens which

have been aged for several years might be used without remeasurement.

Information from the manufacturer suggests that it would be possible to achieve

a X-value at either end of the range just mentioned, simply by controlling

the amount of fluorocarbon in the blowing process. That means that this same material could be used to satisfy both X-value calibration points, in principle. There is one difficulty, which is that the cell wall material is permeable

to water vapor. There can be a variation between 0.014 and 0.019 W/m*K (0.10

and 0.13) with a change in relative humidity from a very low value to a high

value of about 90 percent. A suggestion that warrants investigation is to

seal the surface of a phenolic-foam specimen with a substance such as liquid

applied butyl, which is not very permeable to water vapor. It would probably

be advisable to seal the product in a dried state to avoid long-term drift

problems due to moisture transport within a sealed specimen. A coating of

butyl rubber on either side of the material would increase its thickness by

about 1 mm (30 mils), and the durability of the coating needs to be researched.

17
The research on this candidate material would be similar to that mentioned

previously. Twenty specimens, ten at each end of the A-range, would be

obtained and prepared, and the calibration results for these specimens would

be compared with ten specimens of two other types of foam products at each of

the two A-value calibration points: 0.023 and 0.016 W/m*K (0.16 and 0.11).

In this way the accuracy of such a calibration program would be experimentally

determined. It would also be necessary to re-test the specimens over several

years to look for drift due to aging.

Other possible solutions in this A-value range include the following.

(1) Both the Min-K and the Microtherm products mentioned in items 12 and

13 of section 2.1.1 of appendix 2 have reported A-values of 0.02

W/m*K (0.14), and this is between the two calibration points in

question. This type of product has the distinct advantages that its

properties do not change over time, and it has a wide range of temperature applicability. Its drawback is the A-value dependence on atmospheric pressure. Research would be necessary to see if this dependence can be overcome with a calibration curve as a function of atmospheric pressure. The block form of this product is not very durable,

but a glass-cloth covered version would be quite durable. Again, it

would be necessary to ascertain that the use of different material

and the use of a cover material would not result in a calibration

error.

(2) An aged, extruded polystyrene might be used for the A-value

calibration point of 0.023 W/m«K (0.16).

(3) A surface-sealed, non-aged polystyrene product might be used at

0.016 W/m»K (0.11), provided that the surface sealant prevents

diffusion of the fluorocarbon over time.

Long Term

The following is a suggestion for a long-term solution which is primarily aimed at

solving the material and product variability contributions to calibration error These are the limiting factors in achieving an overall uncertainty of less than

1 percent for calibration specimens in the building-temperature regime. Past

experience at NBS indicates that it is very time-consuming to evaluate and

eliminate the material-variability contribution to calibration error, and the

results have not been very satisfactory. This suggests the desirability of

investigating the feasibility of fabrication of "ultra-uniform" specimen

material. This kind of a solution could apply over the entire range of building

insulation from A-values of 0.014 to 0.072 W/m»K (0.10 to 0.50). An important

conclusion of this report is that such a long-term solution shows promise,

and is warranted in terms of its potential savings of production and testing

expense on the part of the manufacturing community.

18
The basic idea would be to achieve good uniformity by properly mixing

microspheres or micropowders which have a very small unit cell size. The

range of diameters for the materials mentioned in appendix 2 varied from 0.01

to 100 pm. A potential benefit would be the capability to select any desired

X-value over a wide range with the choice of the proportions of two different

microspheres - one of high X-value and another of low X-value.

The issue of uniform mixing is a matter for future research. There is a beginning reservoir of knowledge which has been obtained at the University of

California at Berkeley, Oak Ridge National Laboratory, and the Lockheed Corporation, among others [20], New research problems to be solved include: containment, packing and mixing with regard to uniformity, structural and X-value

stability over time, flatness and resiliency, durability, and dependence on atmospheric pressure or relative humidity.

The X-value range of applicability depends on the low and high limits of

X-value achievable with available materials. The lowest X-value reported was 0.020 W/m*K (0.14) for a 7 millimicron micropowder. There is an indication

that a range of X-value up to point 0.029 W/m»K (0.20) can be achieved

by increasing the diameters of the millimicron powder. The X-value of the microspheres was reported to be about 0.043 W/m»K (0.28) at much greater diameter

values of approximately 50 pm. Thus, future research might show that much

of the thermal conductivity range of interest to the building insulation

industry could be covered with the proper choice of diameter for a single type

of microsphere, without having to mix two different kinds. The interviews

yielded no information as to what the resultant X-value would be of such a composite, and they indicated that there is no experience with mixing higher

X-value microspheres to achieve a higher X-value. In fact, it may be necessary

to make cakes of loose-fill material in layers, and to combine these layers of

different X-value to achieve a desired X-value.

A research program to investigate the feasibility of a loose-fill composite

calibration specimen would involve the following steps. (1) Obtain loose-fill

material and fabricate specimens. (2) Measure the X-value of these various

specimens and determined the dependence on environmental parameters.

(3) Develop techniques for the mixture for the most promising loose-fill

materials. (4) Fabricate composite specimens and measure their X-value.

(4) Determine the material variability (the variation of X-value over a specimen surface area) either using the sectored heat-flow-transducer device

or using such techniques as moving a specimen over the apparatus metered area

or cutting out specimens from one specimen of larger area and independently

testing these cut-out specimens.

The calibration factors determined with the loose-fill materials would be

compared with those determined from the typical insulation materials which arc tested by the user community. If the loose-fill solution proves viable for a flat geometry, then it should be possible to develop it for other geometric..

For example, there is a serious need of a calibration standard for industrial

19
pipe insulation testers, which require a specimen of cylindrical geometry. It

would be very desirable to use the same material for various apparatus geometries. The research problems, in addition to the ones previously mentioned,

would essentially be those of achieving any desired shape. For example, molding

processes might be applicable; or one could try containment solutions which

would involve the fabrication of a containing structure and the pouring or packing of the loose-fill material within the structure. Finally it might be

possible to fabricate a very flexible material which could be wrapped around

cylindrical shapes.

4.3 Recommended Calibration-Specimen Materials at High-Temperature

Short Term

In section 3.4, four regions of X-value were distinguished as areas of need

for calibration standards. These are indicated in table 4 and figure 3. The

greatest needs seem to be for the second region of X-value between 0.058 and

and 0.115 W/m*K (0.4 and 0.8). Work is in progress on a candidate material in

this range. Tests have been made at the Manville Services Corporation on ten

Cera-Fiber specimens. The NBS-Boulder laboratory plans to measure the same

ten specimens. The NBS tests can be made at a temperature as high as 540°C

(930°F). This effort represents a short-term solution in that it will provide

one calibration curve in the high-temperature range.

Long Term

The following long-term work is recommended. First, it would be desirable to

extend the temperature range on this candidate material to about 1000°C (1832°F)

to cover the range of interest for industrial furnaces. This extension in

temperature range could be accomplished either with existing or future NBS

apparatuses, or with other apparatuses with proven state-of-the-art accuracies.

With regard to the issue of the extension of the temperature range to even higher temperatures, measurement activity was reported at temperatures of

1300°C (2400°F) , 2000°C (3600°F) and 2800°C (5100°F). These extremely hightemperature applications were reported primarily by Federal Laboratories which

deal with aerospace applications. Historically, these laboratories have

received enough funding to be self-sufficient. NBS does not have measurement

capability at these high temperatures but is interested in an exchange of

technical information on issues related to this type of measurement.

Other long-term research applicable to regions 1,3, and 4 is indicated in

table 4. The recommended priority order for future standards begins with

region 3, corresponding to brick refractory insulations. It continues with

region 1 corresponding to Min-K, and with region 4 corresponding to the castable

refractories. The reason for this ordering is that there appears to be more activity in the brick-refractory region (3) and this region combined with the

region 2 (which contains Cera Fiber), would cover the (X,T) area that has

20
the most activity. Region 1 corresponding to the Hin-K or Microtherm products

is chosen next because it permits one to bracket either side of the second

region; and this would be an asset in determining the systematic errors for

the various apparatuses. Region 4 (castable refractories) seems to have

less activity, and is an order of magnitude higher in X-value. Depending on

the future, need, a castable refractory could be a candidate for development

after the other three regions have been satisfactorily addressed.

The choice of SRM for the first region would be either the Min-K or Microtherm

product. This product has a strong dependence on atmospheric pressure; between

sea level and an altitude of about 1.6 km (4880 ft), corresponding to Denver,

Colorado, the X-value increases by about 5 percent. There are two possible

solutions to the problems resulting from this dependence. The first is to

consider the atmospheric pressure as a calibration-curve parameter and to

measure over a sufficient number of points to characterize the X-value dependence on this critical parameter. Then the user would then need to measure

both the atmospheric pressure and the X-value to use the calibration standard.

Even if there were a 20 percent uncertainty in the characterization of the

dependence on atmospheric pressure, that would mean that the contribution to

the uncertainty of the X-value would only be 1 percent (multiplying the

worst-case 5 percent by that 20 percent, for example). This error would be

small compared to the systematic errors prevalent for high-temperature measurements, which could be of the order of 3 to 10 percent.

A candidate for the third region is a clay-alumina brick with a density of

960 kg/m^ (60 lb/ft^). This has a fairly constant X-value of about 0.29 W/m»K

(2.0) over the temperature range indicated in figure 3, and this X-value

(2) is high enough to bracket most of the activity indicated.

The candidate for region 4 is a castable refractory with a density of about

2700 kg/m^ (170 lb/ft^). This has a high enough X-value to bracket the

range of activity indicated in figure 3, and there is a possibility it could

be used for the building temperature range where high X-value components

need to be tested.

4.4 Recommended Standards Materials at High Thermal Conductivity and at

Building Temperatures

Figures 1 through 6, based on the interview data in appendix 2, indicate that

measurements have been made in the higher X-value range between 0.028 and

about 2 W/m*K (0.5 and 20). In recent times, NBS has not been called upon

to provide calibration specimens in this range. Users have relied primarily

on a the Dynatech R & D Corporation for calibration information. Or, users have developed a capability to make absolute measurements themselves. The

1-m guarded-hot-plate apparatus of NBS could, in principle, be used at X-valurs

up to 2 W/m»K [4]; but there can be difficulties obtaining sufficiently

large specimens, and there is not as much experience with the evaluation ot

21
errors at high A-value measurements, such as those due to the interfacial

resistance between the specimen and the plate.

If there proves to be sufficient interest, table 5 indicates some candidate

materials for calibration standards. In the past, gum rubber, silicone rubber,

a Pyrex 7740 product, and Pyro Ceram have been tested and used as calibration

standards. NBS, Boulder currently has available Pyro Ceram as a calibration

specimen material. In addition to these, reference [21] lists a number of

plastic materials which cover the entire A-value range of interest. It is

possible that the manufacturing process for some of these materials could

result in intrinsically uniform specimens. It is recommended that this

potential source of calibration specimen material be investigated further.

4.5 Recomendations for Other Thermal Properties

Other thermal properties of interest to thermal testing groups were mentioned

in section 3.6. These included the thermal diffusivity, emittance, radiation

scattering coefficients, and thermal expansion. It would be desirable to have

multiple characterization of calibration specimen material for these other

thermal properties as well as for the A-value.

4.6 Summary Comments on Recommendations

The intention of this section has been to identify the issues and recommended

solutions related to a thermal resistance calibration program. The greatest

emphasis was given to building and industrial insulation materials. Other

materials, properties, and test conditions that should be a part of a comprehensive national calibration program were summarized.

The discussion of recommendations for short- and long-term research reveals

complex issues and trade offs. The resolution of these issues requires substantial research. This research can best be carried out as a cooperative

effort by all parts of the thermal testing community. Management of this

cooperative effort will represent a significant challenge.

22
REFERENCES

1. ASTM Subcommittee C16.30, "Reference Materials for Insulation Measurement

Comparisons," Thermal Transmission Measurements of Insulation, ASTM STP 660,

R. P. Tye, Ed., American Society for Testing and Materials, 1978, pp. 7-29.

2. American Society for Testing and Materials, 1982 Annual Book of ASTM

Standards, (Philadelphia: American Society for Testing and Materials, 1982),

Part 18, ANSI/ASTM C 177-76, "Standard Test Method for STEADY-STATE THERMAL

TRANSMISSION PROPERTIES BY MEANS OF THE GUARDED HOT PLATE," pp. 20-53.

3. American Society for Testing and Materials, 1982 Annual Book of ASTM

Standards, (Philadelphia: American Society for Testing and Materials, 1982),

Part 18, ANSI/ASTM C 518-76, "Standard Test Method for STEADY-STATE THERMAL

TRANSMISSION PROPERTIES BY MEANS OF THE HEAT FLOW METER," pp. 222-253.

4. Rennex, B.G., "Summary of Error Analysis for the National Bureau of Standards

1016 mm Guarded Hot Plate and Considerations Regarding Systematic Error for

the Heat-Flow-Meter Apparatus," presented at the Forum on The Guarded Hot

Plate and Heat Flow Meter - State-of-the-Art in Quebec City, October 7-8,

1982; American Society of Testing and Materials, publication pending.

5. De Ponte, F., Maccato, W., "The Calibration of Heat Flow Meters," ASTM

STP 718, D.L. McElroy and R.P. Tye, editors, American Society for Testing

and Materials, 1980, pp. 237-254.

6. McCaa, D.J., "Implementation of a New Quality-Control Instrument for Thermal

Measurements of a Low-Density Building Insulation,” ASTM STP 718, D.L. McElroy

and R.P. Tye, editors, American Society for Testing and Materials, 1980, pp.

237-254.

7. Rennex, B.G., Somers, T., "Apparent Thermal Conductivity Characterization

of Low-Density, Glass-Fiber Insulation Material," Vol . 8, No. 3, pp. 175-197,

January, 1985.

8. Personal communications on the variation of calibration factor: Mark Albers

of Manville Services Corporation reported 1.6 percent between low-density

and high-density glass-fiber material, a variation of 0.6 percent between

thicknesses of 51 and 152 mm (2 and 6 in), variations as high as 7 percent

when the density varied from 9.6 to 96 kg/m^ (0.6 to 6 lb/ft^) and the

thickness varied from 25 to 203 mm ( 1 to 8 in), no variation with thicknesses

up to 152 mm (6 in) for a 914 mm (24 in) heat flow meter, and a variation of

30 percent as the specimen mean temperature varied from -1 to 52°C (30 to

125°F); Andre Desjarlais of Dynatech R & D Corporation reported typical

variations of 3 percent as the specimen R-values varied from 0.5 to 3.5

m^W/K (3 to 20 ft^ *hr * °F/Btu) and that the variations are a function of

individual apparatus and apparatus design; Stanley Mathews of Rockwool

Industries, Inc. reported a variation of 4 percent between rockwool and

low-density glass-fiber insulation; Hugh Angleton of the NAHB Research

Foundation reported changes of 1 to 2 percent between 25 mm ( 1 in) highdensity and 38 mm (1.5 in) low-density glass-fiber material; Dave McCaa <>f

23
CertainTeed i cpoited caanges of 2 to 4 percent between 25 and

51 mm (1 and 6 in) and changes of 3 percent between high- and low-density

glass-fiber material; and Ron Adams of Owens-Corning Fiberglas Corporation

reported no noticeable change up to 152 mm (6 in) on their large HFM's of

914 and 1219 mm (36 and 48 in).

9. Rennex, B.G., "Low-Density Thermal Insulation Calibrated Transfer Samples —

a Description and a Discussion of the Material Variability," National Bureau

of Standards Interagency Report NBSIR 82-2538 (Washington, DC, NBS,1982).

10. "1982 National Measurement Requirements Survey," National Measurements

Requirements Committee Publication NMRC 83-01, National Bureau of Standards,

Boulder, Colorado, May 1983.

11. "Federal Laboratory Directory 1982," NBS Special Publication 646, James M.

Wyckoff, Editor, Office of Research and Technology Applications, National

Bureau of Standards, Washington, DC, 1983.

12. Heyman, Mat, "Measuring Through Thick and Thin Insulation R-Value,"

Dimensions , National Bureau of Standards, March 1981.

13. "Thermophysical and Electronic Properties Bibliographic Information System,"

issued by Thermophysical and Electronic Properties Information Analysis

Center (TEPIAC), a Department of Defense Information Analysis Center, Center

for Information and Numerical Data Analysis and Synthesis (CINDAS), James F.

Chaney, Wade H. Shafer, and Michael H. Wu, Purdue Research Foundation, West

Lafayette, Indiana, 1982.

14. "Kent's Mechanical Engineers' Handbook," in two volumes, Colin Carmichael,

Editor, Twelfth Edition, Wiley Engineering Handbook Series, New York.

15. ASHRAE Handbook of Fundamentals, Chapter 23, American Society of Heating,

Refrigerating and Air-Conditioning Engineers, Inc., Atlanta, GA (1981).

16. "Modern Plastics Encyclopedia 1983-84," Volume 60, Number 10A, Joan Agranoff,

Editor, McGraw-Hill Inc., New York, 1984.

17. Tye, Ron, et al., "An Experimental Study of Thermal Resistance Values

(R-Values) of Low-Density Mineral-Fiber Building Insulation Batts Commercially

Available in 1977," ORNL/TM-7266 , April, 1980 (available from Oak Ridge

National Laboratory).

18. McElroy, D.L., Graves, R.S., Yarbrough, D.W., " A Flat Insulation Tester That

Uses an Unguarded Nichrome Screen Wire Heater," presented at the Forum on the

Guarded Hot Plate and Heat Flow Meter - State-of-the-Art" in Quebec City,

October 7-8, 1982; to be published by the American Society of Testing and

Materials

.

24
19. Graves, R.S., Yarbrough, D.W., McElroy, D.L., " Apparent Thermal Conductivity

Measurements by an Unguarded Technique," presented at the 18th Thermal

Conductivity Conference, October 3-5, 1983 in Rapid City, South Dakota, to

be published by Plenum.

20. Personnal communications from Michael Rubin, Dave McElroy and George Cunnington,

respectively.

21. "Extruding and Molding Grades 1978," Book B, Published by the International

Plastic Selector, Inc., Cordura Publications, Inc., California, 1977,

pp. B-463 to B-484.

22. "Graduate Program in the Engineering & Applied Sciences 1984," Eighteenth

Edition, Diane Conley, Editor, Peterson's Guides, Princeton, New Jersey, 1982.

25

THERMAL

CONDUCTIVITY

(Btu

•

in/ft

hr

-°F)

FIGURE 1 - ( X ,T) ACTIVITY BY MATERIAL FOR BUILDING TEMPERATURE

INSULATION WNUFACTURERS

TEMPERATURE (°F)

0 100 200 300 400 500 600 700

0.14

0.13

0.12

0.11

0.10

0.09

0.08

0.07

0.06

0.05

0.04

0.03

0.02

0.015

l.U

0.9

0.8

0.7

0.6

0.5

0.4

0.3 -

0.2 -

n i

BUILDING-TEMPERATURE RANGE

I

I

VERMICULITE, LOOSEFILL MINERAL FIBER

PERLITE, MINERAL-FIBER BATTS

LOW-DENSITY, MINERAL-FIBER BATTS

SOME MINERAL-FIBER LOOSE FILL

A MINERAL-FIBER BATTS

T CELLULOSE LOOSE FILL

*

HIGH-DENSITY, GLASS-FIBER

POLYURETHANE, POLYSTYRENE FOAMS

POLYISOCYANURATE FOAM

PHENOLIC FOAM (CLOSED-CELL)

0 50 100 150 200 250 300 350

TEMPERATURE (°C)

A-l

THERMAL

CONDUCTIVITY

(W/m-K)
THERMAL

CONDUCTIVITY

(Btu-in/ft

2

-hr-°F)

FIGURE 2 - ( A,T) ACTIVITY BY MATERIAL FDR INDUSTRIAL INSULATION

MANUFACTURERS

TEMPERATURE (°F)

0 100 200 300 400 500 600 700

A-2

THERMAL

CONDUCTIVITY

(W/m-K)
THERMAL

CONDUCTIVITY

(Btu-in/ft

2

-hr-°F)

FIGURE 3 - (A/T) ACTIVITY BY MATERIAL FOR INDUSTRIAL INSULATION

MANUFACTURERS

TEMPERATURE (°F)

-200 0 200 500 1000 1500 2000

A-3

THERMAL

CONDUCTIVITY

(W/m-K)
THERMAL

CONDUCTIVITY

(Btu-in/ft^-hr

• F)

50

20

10

5

2

1

0.8

0.5

0.4

0.3

0.2

0.15

0.10

FIGURE H - ( \A) ACTIVITY BY MATERIAL FOR COMMERCIAL LABORATORIES

TEMPERATURE (°F)

-200 0 200 500 1000 1500 2000

10

5

1

0.5

0.2

0.1

0.06

0.05

0.04

0.03

0.02

0.015

-100 0 100 200 400 600 800 1000 1200

TEMPERATURE (°C)

^—1

nr 1 1 II

PYRO CERAM

PYREX

_

i k

CONCRETE

1 GRAPHITE

FIBERS

TEFLON, EPOXY

GUM RUBBER , i — REFRACTORIES

INSULATING A

I CEMENT

1

i —

-

BUILDING

INSULATIONS

' —

i L 1 J ! 1 1 1 1

A-4

THERMAL

CONDUCTIVITY

(W/m*K)
THERMAL

CONDUCTIVITY

(Btu

•

in/ft 2

- hr

-°F)

FIGURE 5 - (A/T) ACTIVITY BY MATERIAL FOR UNIVERSITIES

TEMPERATURE (°F)

-200 0 200 500 1000 1500 2000

10

5

1

0.5

0.2

0.1

0.06

0.05

0.04

0.03

0.02

0.015

-100 0 100 200 400 600 800 1000 1200

TEMPERATURE (°C)

50

20 -

10 -

5 -

CERAMICS

SOILS

2 -

1

0.8

0.5

0.4

0.3

0.2

0.15

n io

PLASTICS

MOIST

INSULATION

^REFRACTORIES

BUILDING

INSULATIONS (RADIATION)

MICRO-POWDER (RADIATION)

I I I I

A-5

THERMAL

CONDUCTIVITY

(W/m-K)
THERMAL

CONDUCTIVITY

(Btu-in/ft

2

.hr-°F)

FIGURE 6 -

( A,T) ACTIVITY BY MATERIAL FOR FEDERAL LABORATORIES

-200 0 200

TEMPERATURE <°F)

500 1000 1500 2000

50

20

10

1 0.8

0.5

0.4

0.3

0.2

0.15

0.10

-1

r \ i

1

—T ~

—

PYRO CERAM

—

i i

—

PYREX CARBON FI 3ER

VOLCANIC

ROCK

GLASS

TEFLON —

WOOD

. .. t

' — REFRACTORIES 1 —

FIBER BOARD ~ i k BUILDING INSULATION

| —

CLOTHING —

i'alumina MICRO-POWDERS — FIBER — y ! ... .

i J 1 1 1 1 _l -

~ 10

- 5

— 0.5

0.2

0.1

0.06

0.05

0.04

0.03

0.02

0.015

-100 0 100 200 400 600 800 1000 1200

TEMPERATURE (°C)

A-6

THERMAL

CONDUCTIVITY

(W/m-K)
FIGURE 7 - SECTIONED HEAT-FLUX-TRANSDUCER DEVICE

• There is a separate readout from each of the four areas

indicated by different shading.

• For a 1 W/m-K heat flux, the independent readout values

in mV for sections 1-4 are 0.29, 1.57, 1.79, and 2.13,

respectively.

• The outer unshaded area is a guard material with the

same R-value as that of the central sections.

A-7
Table 1 — Candidates for Standard Reierence Material recommended by

1978 ASTM study.*

•Material

Probable Temperature

Range of Applicability. °C

Nominal Bulk

Densitv. kg ms

(lb/ft 3

)

Thermal Resistance per Unit Thickness at 25*C. m K'W |h ft’ °F (Btuin. )] Need or Use

1 . Air space -160 to 200 procedural use. test plate emitiance. and plate orientation effects

2 High-density molded fibrous

glass board -175 to 150 80 to 160

(5 to 10)

31.5

(4.5)

historical NBS material minimum

radiation effect

3. AA glass fiber blanket

insulation - 100 to 400 9.6

(0.6)

31.5 to 28.9

(4.5 to 4.2)

radiation effects, temperature coefficient. and geometry (thickness)

effects

4 Glass fiber appliance

insulation blanket -100 to 230 1 1 to 32

(0 7 to 2) 20 4 to 28.9

(2.9 to 4.2)

similar to Item 3

5. Aged polystyrene foam - 180 to 75 48

(3)

21.7 to 22.4

(3.1 to 3.2) provides useful comparison to 8.9- cm (3 i -5 in.) fiber glass baits, sta- ble after aging

6 Silicone rubber glass point to 250 1280 to 1600

(80 to 100)

4.08 to 2.77 (0.59 to 0 40) opaque material, interfacing resist- ance effects, and thickness edgeloss effects

7. Borosilicate glass -175 to 800 2000

(125)

0.96

(0.14)

interfacial resistance effects, radia- tion effects at high temperature, and thickness effects

8 Closed-cell foam glass -175 to 350 140 to 160

(9 to 10)

16.5 (2.38)stable with reproducible properties

9. Silica aerogel composite

block -175 to 900 320

(20)

38.5

(5.5)

high thermal resistance per unit thickness tests and steady-state

capacity temperature coefficient

10 Rigidized silica fiber tile -175 to 1000 160

(10)

27.8

(4.00)

radiation' "effects and known

reproducibility

1 1 . Zircoma fiber board -175 to 2200 480

(30)

11.55 (167)

very-high-temperature use, temperature coefficient, and radiation

effects

12. Alumina-silicate refractory

fiber insulation blanket -175 to 1250 64(4)

30.1

(4.34)

radiation and thickness effects, high- temperature geometry effects, and

temperature coefficient

13. Mineral rock board -175 to 650 192

(12)

23.1

(3.3) .

radiation effects, temperature coefficient. and geometry effects

14. Calcium silicate -175 to 700 190 to 220

(12 to 14)

17.3

(2.5)

generic insulation-type radiation and geometry effects and temperature

coefficients

15. Powder or loose-fill insulation

specimen preparation techniques,

radiation effects, isotropic nature. and temperature coefficient

*Ref erence : ASTM Subcommitte C16.30, "Reference Materials for Insulation

Measurement Comparisons", Thermal Transmission Measurements of

Insulation, ASTM STP -660, R. P. Tye, Ed., Americam Society for

Testing and Materials, 1978, pp. 7 - 29.

A-8
TABLE 2 - Useful Information for Reference Materials *

GENERAL DESCRIPTIVE INFORMATION

1. Material name; ASTM designation if appropriate

2. Source or sources

3. Production process description, commercial or custom product

4. Material constituents, chemical analysis, fiber characteristics,

binders used, special heat treatments

5. Product forms and densities available and prices of products

6. Typical product applications

7. Precautions on product usage

PHYSICAL PROPERTIES AS A FUNCTION OF TEMPERATURE

1. Thermal resistance or thermal resistance per unit thickness or thermal conductivity (where applicable) (method and qualifications)

2. Density

3. Specific heat

4. Thermal diffusivity

5. Thermal shock resistance

6. Thermal expansion coefficient

7. Anisotropy of any physical property

8. Emittance, transmittance, and absorptance

MECHANICAL PROPERTIES AS A FUNCTION OF TEMPERATURE

1. Compressive, tensile, and shear strengths

2. Deflection versus load for different thicknesses, density,

and temperatures

OTHER PERTINENT PROPERTIES

1. Combustibility

2. Corrosive effects on materials or by various chemicals

3. Hygroscopic and moisture resistance degradation

4. Resistance to airflow

5. Clearly defined maximum-use temperature for various exposure times

6. Linear dimensional changes and other insulation property changes

with aging time at temperature

7. Safety (hazard) and health (toxicity) considerations

* Reprinted from table 3 of reference [1].
TABLE 3 - SUGGESTED THERMAL CONDUCTIVITY VALUE CALIBRATION POINTS FOR

BUILDING INSULATION*

APPARENT THERMAL CONDUCTIVITY

SI UNITS

(W/m-K)

ENGLISH UNITS

(Btu* in/ft^’hr* °F)

TYPICAL GENERIC MATERIAL

0.016 0.11 Non-Aged Fluorocarbon-Blown Products

0.023 0.16 Aged Fluorocarbon-Blown Products

0.033 0.23** High-Density Glass-Fiber Product

0.040 0.28 Loose-Fill Cellulosic and Some

Mineral-Fiber Batt Products

0.046 0.32** Low-Density Glass-Fiber Batt and

Some Loose-Fill Mineral -Fiber

Products

* Building-Temperature Range: -35 to 65°C (-30 to 150°F)

** NBS currently provides calibration specimens in this X-value range.

A- 10
TABLE 4 - SUGGESTED MATERIALS AND THERMAL CONDUCTIVITY VALUES AT HIGH-TEMPERATURES*

APPARENT THERMAL CONDUCTIVITY

REGION** SI UNITS

(W/m* K)

ENGLISH UNITS***

(Btu*in/f t2»hr* °F)

SRM CANDIDATES

1 0.043 0.3 Ceramic-Silica (Min-K or Microtherm)

2 0.057 - 0.11 0.4 - 0.8 Aluminum Silicate Fiber

3 0.14 - 0.29 1 - 2 Brick Refractory

4 2.16 15 170 lb/ft^ Castable Refractory

* High-Temperature Range: 100 to 1200°C (200 to 2200°F).

** For convenience the thermal conductivity range was divided into four regions.

See discussion in sections 3.4 and 4.3 and in section 1.3 of appendix 1.

*** Thermal parameter values for the various insulating materials were obtained

from the literature or from researchers. These values were not based on research at NBS.

A-ll
TABLE 5 - SUGGESTED MATERIALS AT HIGH THERMAL CONDUCTIVITY VALUES

AT BUILDING-TEMPERATURES

APPARENT THERMAL CONDUCTIVITY*

SI UNITS

(W/m*K)

ENGLISH UNITS

(Btu*in/ft2*hr*°F)

CANDIDATE MATERIALS

0.16 1.1 Gum Rubber

0.29 2 Silicone Rubber

1.01 7 Pyrex 7740

3.61 25 Pyro Ceram

* Thermal parameter values for the various insulating materials were obtained

from the literature or from researchers. These values were not based on research at NBS.

A-12
APPENDIX 1. User Interest and Test Activity

1.1 Introduction

The discussion in the following sections is an overview based on the more

detailed version given in appendix 2. It presents information obtained in

conversations with many users, or potential users, of thermal conductivity

calibration specimens. It is organized by user group categories, and within

these categories, by increasing X-value. The following additional appendices

are provided as information resources for the reader. Appendices 4 and 5 provide lists of insulating materials ordered alphabetically and by decreasing

X-value, respectively. Appendix 6 lists members of associations of insulation

manufacturers

.

Because of the nature of this report, which is to assess the kinds of products

that are actually in use, there will be an occasional use of a trade name or a manufacturer’s name. This in no way represents an endorsement of a particular

product or manufacturer.

1.2 Activity and Interests of Manufacturers of Building Insulation

The implied temperature range corresponds to building applications. Refer to

figure 1. ^The X-values are expressed in SI units; the English units

(Btu»in/ft •hr»°F) are given immediately afterwards in parentheses.

1.2.1 X = 0.014 ~ 0.019 W/m»K (0.10 - 0.13)

For the most part, the materials in this range are the fluorocarbon-blown foams

polyurethane, polystyrene, polyisocyanurate , and phenolic foam. The first

three materials were reported to be in this range only when initially produced,

and the last material was reported to stay in this range when aged.

1.2.2 X = 0.020 ~ 0.026 W/m»K (0.14 - 0.21)

This range includes the aged foam products just mentioned.

1.2.3 X = 0.032 - 0.036 W/m»K (0.22 - 0.25)

This range includes the high-density, glass-fiber boards, some aged polystyrene

and expanded polystyrene.

1.2.4 X = 0.039 - 0.042 W/m«K (0.27 - 0.29)

This includes mineral-wool batt and blanket and loose-fill cellulose material.

1-1
1.2.5 X = 0.045 ~ 0.049 W/m-K (0.31 - 0.34)

This includes low-density, glass-fiber batt and blanket insulation and

some loose-fill mineral fiber material.

1.2.6 X = 0.055 - 0.10 W/m-K (0.38 - 0.7)

This includes wood fiber board, perlite, vermiculite-aggregate concrete and

insulating concrete.

1.3 Activity and Interests of Manufacturers of Industrial Insulation by

Increasing Thermal Conductivity Value

Industrial insulation is produced over a wide range of thermal conductivity.

In order to simplify the discussion, this range was divided into four regions

- corresponding to the approximate X-values (at 24°C or 75°F): (1) X = 0.030 W/m-K

(0.21), (2) X = 0.060 W/m-K (0.42), (3) X = 0.14 W/m-K (1.0), and (4) X = 1.4 W/m-K

(10). Refer to table 4.

1.3.1 Region 1

Over most of the high-temperature range, there are only two commercial materials.

The first is the Min-K product (refer to Appendix 2 and to Figures 2 and 3).

The mixture of a fibrous material with a radiation-blocking silica powder

results in a very low X-value. This product varies in X-value between

0.029 W/m-K (0.20) at 94°C (200°F) to 0.068 W/m-K (0.47) at 820°C (1500°F). A

lower value of 0.02 W/m-K (0.14) was reported at 24°C (75°F) based on measurements

at Denver, Colorado. The second is a similar product. It is a microporous

ceramic-silica material called Microtherm which also does not age and which

also does vary in X-value with atmospheric pressure. It varies in X-value

from 0.02 W/m-K (0.14) at 24°C to 0.04 W/m-K (0.28) at 500°C (932°F).

Referring to figure 2, there are also other kinds of insulation at the low

temperature part of the graph. These include some high-density glass-fiber

industrial insulation material, a silica-fiber product, a mineral wool product,

and possibly some varieties of microspheres.

1.3.2 Region 2

Referring to figures 2 and 3, there are a number of generic products that cover temperatures up to 1000°C (1800°F) or higher. These generally have a X-value

of about 0.058 W/m-K (0.40) at 24°C (75°F) and extend up to a X-value of

about 0.22 W/m-K (1.5) at 1100°C (1600°F). These include calcium silicates

(CaSi04), ceramic felts, alumina-silica-fiber insulation (Cera Fiber), a matted glass-fiber, a fine glass-fiber (aircraft insulation), and foam glass.

For each generic insulation type, it is possible to have a wide range of X-values

depending on the insulation density. The higher density products have a

1-2
higher X-value in the lower temperature range and a lower X-value in the

higher temperature range, than the equivalent lower density insulation.

1.3.3 Region 3

Region 3 includes a clay-alumina brick, a marinite calcium silicate product,

and zirconia fiber board.

1.3. A Region 4

Region 4 includes a clay-alumina brick, and castable refractories. As the

density of the castable material varies over its range, the entire X-value

range can be covered up to about 2 W/m*K (14).

1.4 Activity and Interests of Commercial Testing Laboratories

Referring to the interview data in section 2.2 of appendix 2 and to figure 4,

the commercial testing laboratories reflect, for the most part, the manufacturers'

and the federal laboratories' activity. Some testing laboratories measure, as their main activity, the usual building insulations for purposes of certification.

Others concentrate more on high-temperature materials such as refractory insulation,

and on composite materials such as graphite-fiber materials. Some measurements

have been made on the higher conductivity materials — such as gum rubber,

plastics, epoxies, or concrete; but there is little current activity in these

regions

.

The majority of testing, in the higher conductivity range, corresponds to the

Pyrex or Pyro Ceram materials — for high temperature work.

1.5 Activity and Interests of Universities

Referring to section 2.3 in appendix 2 and to figure 5, starting at the

very low X-value range there is some research, both experimental and theoretical,

at about 0.02 W/m*K (0.14) on micropowders. The X-value has been measured

and calculations on radiation heat transfer have been made. There is research

activity at about six universities on the measurement and corresponding theory

of the absorption and scattering cross sections for building insulations.

Between 0.043 and 0.29 W/m*K (0.3 and 2), there is a need for calibration standards

to measure the X-value of moist insulation. There is some interest at the X-value

range of about 0.14 W/m*K (1) in plastics. There is considerable activity in

terms of theoretical work in the regions corresponding to refractories.

However, there is not much experimental work in this region due to the high

cost of high-temperature experimental apparatus. There has been some research

which requires a knowledge of the X-value of soils both for geothermal and

slab-on-grade studies. Research has been carried out in the areas of natural

and forced convection problems — at cryogenic and at building temperatures.

This includes work on composites such as, solids plus liquids, or solids plus

solids. There has been some work on high temperature materials such as ceramics;

1-3
a problem here Is that much of the data on thermophysical properties collected

by the aerospace industry is proprietary. Another effort deals with thermal waves such as the ones that result from a daily change in solar radiation on

the surface of the earth.

For the most part, the university researchers are interested in the understanding

of the heat transfer process and physical phenomena. For this reason, they

are interested in other thermophysical properties such as thermal diffusivity

and surface emittance, especially at high temperatures. In the building insulation

range, there is an interest in modeling heat transfer in the materials, and

considerable experimental work is being conducted in this range. At high

temperatures there is more theoretical activity and less experimental activity

because of the high cost of the corresponding apparatus. However, there is a great deal of dependence on handbook values for physical parameters in their

models. There is general agreement that this dependence leads to inaccuracy

of results and that a broader range of calibration standards would be of considerable help in the validation of the researchers' models [10].

1.6 Activity and Interests of Federal Laboratories

Referring to figure 6 and to the interview data in section 2.1.2 in appendix 2,

there has been some research on the micropowders both as insulation and as possible fenestration material. In the building insulation range, there has

been some work on clothing material. This research requires knowledge of

permeability, of radiation and convection heat transfer at the surfaces,

and of conduction heat transfer through the clothing material.

There has been considerable work on building insulations and methods of installation. This includes field studies at residential installations, measurements

of the entire spectrum of insulations in test labs, and lab work on building

systems. There has been testing of higher conductivity materials such as wood, teflon, aluminum fiber, glass, and volcanic rock.

In the high-temperature range the major emphasis is on aerospace and fire

applications. There is interest in materials which could withstand a temperature

of 2800°C (5070°F) for rocket application. In the area of fire research, the

temperature range of interest could be as high as 1300° C (2370°F). The work

requires a knowledge of a great number of high temperature materials such as ceramic cloths, insulating foams, ablative materials, microspheres, adhesive

systems, and hybrids of these. The temperature range of 800 to 1400°C (1500

to 2550°F), is of interest for aerodynamic heating; and, here, there is interest

in materials such as ceramics, pyro ceram, adhesives, composites, and silicone rubber.

Thus, there is some interest in the building insulation range, and there seems to

be relatively more interest in the high temperature range corresponding to aerospace materials. In addition, some interest was expressed in other thermal properties

such as thermal diffusivity and surface emittance at this high-temperature

range. There is also some interest in high-X materials at room temperature.

1-4
APPENDIX 2. Interview Data

As part of the effort to identify candidate reference materials for thermal

measurements, telephone inquiries were made from people involved in heattransfer work. The interviewees were asked to give a brief statement of the

nature of their work and to list the materials for which they might need to

know the thermal conductivity value. The following is a list of summary

statements based on the interview data from a representative sampling of these

users. In most cases the respondents listed only the tested materials which

they produce. In some cases the respondents listed additional materials which

they have tested, but which they do not produce. It is noteworthy that, in

general, the industrial researchers test a wider range of materials than what

is indicated below. An overview of the information in this appendix is

presented in appendix 1.

Because of the nature of this report, to assess the kinds of products that are actually in use, there is occasional use of a trade name or a manuf actuar 's name. This in now way represents an endorsement of a particular product or manufacturer. Also, the thermal parameter values for the various insulating

materials were obtained from the literature from researchers. These values

were not based on research at NBS. Reference [15] explains the various

categories of insulation materials.

The X-values are given as two numbers — the first in SI ^nits of W/m»K and

the second (in parentheses) in English units of Btu»in/ft »hr»F. The

temperature is given in °C (°F), and the units for density are kg/m^ (lb/ft^).

2.1 Manufacturers

2.1.1 Building and Industrial Manufacturers

1. American Hoechst Corporation

Contact Person: Mich Yokinen

289 North Main Street

Leominster, MA 01453

(617) 537-8131

Product Type - polystyrene [X-value of 0.030 (0.21)]

2. Apache Building Products Inc.

Contact person: Mr. Tomasum

2025 E. Linden Avenue

Linden, NJ 07036

(201) 486-6723

Product Type - polyurethane [X-value of about 0.025 (0.17)]

2-1
3. Butler Manufacturing Company

Contact Person: Charles Milburn

13th St. & Botts Road

Grandview, MO 64030

(816) 763-3022

Product Type 1 - glass-fiber [ X-value of about 0.046 (0.32)]

Product Type 2 - polystyrene [X-value of about 0.036 (0.25)]

Product Type 3 - urethane type foam [A-value of about 0.025 (0.17)]

Heat-Transfer Apparatus - Guarded-Hot-Box, Heat-Flow-Meter

They test products at 8°C (45°F) and 24°C (75°F).

4. Cellulose Industry Standards Enforcement Program

Contact Person: Vernon "Skip" Lowe

610 Center City Office

Dayton, OH 45402

(513) 222-1024

Product Type - loose-fill cellulose [X-value of about 0.039 (0.27)

and density of 32 to 48 kg/m^ (2 to 3 lb/ft^)]

This program represents about 25 percent of the cellulose production. There are about 150 companies producing cellulose. The testing for the enforcement

program is done by Underwriters Laboratories, Inc.

5. CertainTeed Corporation

Contact Person: Dave McCaa

1400 Union Meeting Road

Blue Bell, PA 19422

(215) 542-0500

Product Type 1 -

Product Type 2 -

Product Type 3 -

a low-density glass-fiber [ X-value of ~ 0.048

to 0.049 (0.33 to 0.34) and density of ~ 10 kg/m^

(0.6 lb/ft^).] The test temperature is 24°C (75°F).

loose-fill, glass fiber insulation [X-value of

about 0.045 (0.31) and density of about 14 kg/m^

(0.9 lb/ft^)]. The test temperature is 24°C (75°F).

industrial glass-fiber insulation [A-values range

from 0.033 to 0.043 (0.23 to 0.30), and density

ranges from 12 to 96 kg/m^ (0.75 to 6 lb/ft^)]. This

material can be used at temperatures up to 450°C

(850°F)

.

2-2
6. Dow Chemical

Contact Person: Dave Greason

P. 0. Box 515

Granville, OH 43023

(614) 587-4362

Product Type - extruded polystyrene foam [A-values range at 24°

C

(75°F) from 0.024 to 0.032 (0.165 to 0.22). The density

range is from 26 to 64 kg/m^ (1.6 to 4 lb/ft-^), and the

A-value depends on more than just the density. The

A-value at 5°C (40°F) is 0.027 (0.185)]. Tests have

been conducted at -162°C (-260°F) (the A-value here is

approximately 0.08 (0.56)), at the liquid-natural-gas

temperature of approximately -40°C (-40°F), and at

high temperatures. The product thickness ranges

from 13 mm to 25 cm (0.5 to 10 in). The polystyrene

uses a mixture of oxygen, nitrogen, and fluorocarbon

as a blowing agent, and this diffuses out of the

material over time, with a corresponding increase

in A-value. The A-value of the fresh blown product

is 0.016 (0.11). First, the oxygen and nitrogen

diffuse out in about 60 days, at which time the A-value

is 0.017 (0.115) for a 25 mm (1 in) product. The

fluorocarbon diffuses out over a longer period of time.

After 5 years, typical products would have a A-value of

0.20. Over the next 45 years this value would not be

expected to change more than another 5 percent.

There are not good data on exactly how uniform the

material is; an estimate was that over a large 122 x 244 cm (4 x 8 ft) specimen the A-value would not vary

by more than 2 to 3 percent. Tests of products other

than those produced by Dow Chemical are conducted over

a wider range of A-values.

Heat-Transfer Apparatus - Heat-Flow-Meter and a Calibrated-Hot-Box.

7. Fibrex

Contact Person: Jane Wood

P. 0. Box 1148

Aurora, IL 60507

(312) 896-4800

Product Type 1 - high-temperature mineral-wool insulations with a density range from 40 to 320 kg/m-* (2.5 to 20 lb/ft^).

The range of temperature applicability is 24°C (75°F)

to approximately 1080°C (1900°F). At a density of

128 kg/m^ (8 lb/ft^), the A-value is approximately

0.045 (0.31) for a mean temperature of 95°C (200°F).

2-3
This material is used in loose form and in insulating

cements

Product Type 2 - Alumina-silica fiber in block form - The density is

approximately 288 kg/m^ (18 lb/ft^) and the temperature

limit is 1260°C (2300°F). The A-value at 538°C (1000°F)

is approximately 0.088 (0.61).

8. Jim Walter Research Corporation

Contact Person: Gerry Miller

10301 9th Street N

St. Petersburg, FL 33702

(813) 576-4171

Product Type 1 - Thermax Insulation Board (a foil-faced polyisocyanurate

foam). [A-values range from approximately 0.016

to 0.020 (0.11 to 0.14) at 24°C (75°F)]. The nominal

density value is 32 kg/m^ (2.0 lb/ft^). The thickness

range is 12 to 108 mm (0.5 to 4.25 in).

Product Type 2 - Tuff-R Insulating Sheathing (a foil-faced polyisocyanurate

foam). [A-values range from approximately 0.016 to

0.020 (0.11 to 0.14) at 24°C (75°F)J. The nominal

density value is 32 kg/m^ (2.0 lb/ft^). The thickness

range is 12 to 25 mm (0.5 to 1.0 in).

Product Type 3 - Thermax Hy-Tec (Energy-LoK) Roof Insulation (a glassfiber faced polyisocyanurate foam). [A-values range

from approximately 0.016 to 0.023 (0.11 to 0.16) at

24°C (75°F)]. The nominal density value is 32 kg/m^

(2.0 lb/ft^). The thickness range is 19 to 102 mm

(0.75 to 4.0).

Product Type 4 - Thermax Hy-Tec Plus Roof Insulation (a composite

fiberboard, glass-fiber faced polyisocyanurate foam).

[A-values range from approximately 0.023 to 0.032

(0.16 to 0.22) at 24°C (75°F)]. The thickness

range is 38 to 84 mm (1.5 to 3.3 in).

Product Type 5 - Fiberboard Insulation (cellulosic fiberboard).

(A-value is approximately 0.052 (0.36) at 24°C

(75°F).] The density is about 320 kg/m^ (20.0

lb/ft^). The thickness range is 12 to 51 mm (0.5

to 2.0 in).

Product Type 6 - CeloTherm Perlite Roof Insulation (expanded volcanic

glass). [A-value is approximately 0.052 (0.36)

at 24°C (75°F).] The thickness range is 19 to 51 mm

(0.75 to 2.0 in).

2-4
Heat-Transfer Apparatus - Heat-Flow-Meter, Guarded-Hot-Plate , Guarded/

Calibrated Hot Box.

Some tests are made at a mean temperatures of 40°C (110°F) and 5°C (40°F).

9. Knauf Fiber Glass

Contact Person: David Anewalt

240 Elizabeth Street

Shelbyville, IN 46176

(317) 398-4434

Product Type 1 - low-density, glass-fiber insulation [ X-value of

0.046 (0.32); density of about 9 kg/m^ (0.6 lb/ft^).]

Product Type 2 - glass-fiber insulation in the form of rolls, batts,

and pipe covering [X-values range from 0.033 to

0.043 (0.23 to 0.30) and density values range from

12 to 96 kg/m^ (0.75 to 6 lb/ft^). The temperature

range of use of this material is from 24°C (75°F)

to 454°C (850°F) .

]

10. Koppers Company

Contact Person: Rod Shapard

440 College Park Drive

Monroeville, PA 15146

(412) 227-2270

Product Type - phenolic foam (closed-cell) [X-value ranges from

about 0.014 to 0.022 (0.10 to 0.15); the density is

42 kg/m^ (2.6 lb/ft^).] The thickness varies from

13 to 90 mm (0.5 to 3.6 in). The range of temperature

applicability is 27 to 177°C (80 to 350°F). The X-value

can vary by as much as 30 percent with relative humidity.

It was reported that over a period of 3 years there was

no measurable change in X-value. Thus, there must

have been only a negligible amount of diffusion of the

fluorocarbon blowing agent out of the specimens. That

is, the cell-wall material seems to be unusually

impermeable to the fluorocarbon. The reported estimate

of the amount of variation of the X-value over the

specimen area was 1 percent. Since the material is

machinable, it should be possible to improve on the

manufactured flatness of 1.3 mm (50 mils). There may

be a problem with breakage of large specimens.

2-5
11. Lockheed Palo Alto Research Laboratories

Contact Person: George Cunnington

D52-32, B205

3251 Hanover Street

Palo Alto, CA 94304

(415) 424-2426

12 .

This is a partial list of the materials that they test.

Product Type 1 - silica fiber insulation- The density ranges between

96 and 720 kg/m^ (6 and 45 lb/ft^); the X-value at

24°C ( 75°F) is about 0.058 (0.4) and at 1000°C (1831°F)

it is 0.29 (2.0). The estimate of uniformity in X-value

was 2 percent. This material is used in the spaceshuttle tile, and it can be metalized for hightemperature applications.

Product Type 2 - carbon and graphite-fiber materials {The X-value

is the order of 1 (7) and it is tested at temperatures up to 1000°C (1800°F).]

Product Type 3 - Approximately ten years experience in testing a variety of loose-fill micro-powders has been gained.

Manville Services Corporation

Contact Person: Dick Troyer

P. 0. Box 5108

Denver, CO 80217

(303) 978-5312

Product Type 1 - low-density glass-fiber insulation [The X-value

at 24°C (75°F) is 0.049 (0.34); the density range is

8 to 11 kg/m^ (0.5 to 0.7 lb/ft^).]

Product Type 2

Product Type 3

Product Type 4

medium-density glass-fiber insulation [ X-value

of 0.032 (0.22); density of 40 kg/m^ (2.5 lb/ft^).]

a glass-fiber board [X-value of 0.036 (0.25);

density of 80 kg/m^ (5 lb/ft^).]

a polyurethane foam product for use at building

temperature. [Six month X-value ranges from 0.023

(0.16) at a thickness of 33 mm (1.3 in) to 0.019

(0.135) at a thickness of 69 mm (2.7 in); density of

about 32 kg/m^ (2 lb/ft^).]

Product Type 5 - polyisocyanurate foam [Six-month-age X-value of

about 0.023 (0.16) at 24°C (75°F); density of about

32 kg/m^ (2 lb/ft^).]

2-6
Product Type 6 - Min-K (made for use at high-temperature and vacuum

conditions, although it can be used at a lowtemperature and/or an atmospheric-pressure condition.)

This material is formed from fibrous material mixed

with heat resistant silica powder as an opacifier.

The product brochure indicates a X-value (at atmospheric

pressure) of 0.029 (0.20) at 94°C (200°F), of 0.043

(0.30) at 650°C (1200°F), and of 0.068 (0.47) at

820°C ( 1500°F) , for a density of 320 kg/m3 (20 lb/ft3

).

A personal communication from Mark Albers of Manville

stated that a measurement at Denver, Colorado gave

the X-value at 24°C (75°F) of 0.02 W/m*K (0.14),

which is lower than what the product curves would

indicate. At higher altitudes the X-value is

smaller; for example, at an altitude of 10 miles it can decrease by as much as 50 percent. The X-value

depends significantly on the atmospheric pressure.

There is about a 5 percent decrease in X-value at

Denver, Colorado from the value at sea level. On

the other hand there is only a small dependence

of X-value on relative humidity. Min-K is produced

in a blanket form at a thickness of 25 mm (1 in),

and it is produced as a molded product in all shapes

.

Flatness is indicated to be as good as +2 mils, and an estimate of X-value variability over a specimen

area is perhaps 2 to 3 percent. Depending on the

product the maximum temperature of use varies from

about 7 00°C (1300°F) to 1100°C (2000°F).

Product Type 7 - calcium silicate — This is used at temperature

range between 40 to 540°C (100 and 1000°F). [The curve for the X-value as a function of temperature

depends on the density; for a density of 190 kg/m3

(12 lb/ft 3

) the X-value at 40°C (100°F) is 0.053

(0.37), and at a temperature of 540°C (1000°F) the

X-value is 0.127 (0.88). At a higher density of

about 800 kg/m3 (50 lb/ft3

), the X-value at 24°C

(75 °F) is 0.13 (0.88), at 260°C (500°F) the X-value

is 0.115 (0.80), and at about 540°C (1000°F) the

X-value is 0.12 (0.86).] The estimate of the X uniformity is about 1 percent.

Product Type 8 - alumina-silica fiber (Cera Fiber). This material is a candidate for a Standard Reference Material (SRM).

It has been tested by Manville Service Corporation

and they will provide ten specimens to NBS (Boulder)

for further testing. This material has a density of

240 kg/m3 (15 lb/ft3

). The entire range in density

is between 192 and 416 kg/m3 (12 to 26 lb/ft^). For

the 240 kg/m3 (15 lb/ft 3

) density, the X-value at

2-7
Product Type 9

Product Type 10

Product Type 11

Product Type 12

94°C (200°F) is 0.050 (0.35), at 540°C (1000°F) it

is 0.11 (0.75), and at 980°C (1800°F) its value is

0.18 (1.25). The variation of X over area is

estimated to be less than 3 percent.

alumina-silica fiber - the generic material described

above is available over a wide range of density,

from 48 to 384 kg/m^ (3 to 24 lb/ft^). Temperature

limits for application range between 870 to 1538°C

(1540 to 2800°F). At the low end of the temperature

range [260 to 540°C (500 to 1000°F)], the following

statement holds. The X-value for the lower density

products is lower than the X-value for the higher

density products. At the higher temperatures such as 800 to 1100°C (1500 to 2000°F), the X-value is higher

than in the case of the higher density material.

clay-alumina brick refractory insulation - [density

ranges from 540 to 1500 kg/m-* (34 to 95 lb/ft^). At

the density value of 560 kg/m-* (35 lb/ft-*), and at the

temperature of 260°C (500°F), the X-value is 0.13

(0.90); at 540°C (1000°F), X is 0.16 (1.1); at 816°C

(1500°F) , X is 0.20 (1.4); and at 1100°C (2000°F)

X is 0.23 (1.6). For a density value of 960 kg/nH

(60 lb/ft^) and a temperature of 260°C (500°F), the

X-value is 0.36 (2.5); at 540°C (1000°F), X is 0.375

(2.6); at 816°C (1500°F), X is 0.40 (2.8); and at

1100°C (2000°F), X is 0.43 (3.0).] This material is

particularly resistent to chemical degradation.

castable refractory insulation made of clay, calcium,

aluminate. and cement - [density ranges from 720 to

2700 kg/m-* (45 to 170 lb/ft-*).] At the low end of

the density range, the X-value behaves very similarly

to the 960 kg/m-* (60 lb/ft^) clay alumina brick

described above, at the high end of the density range

its X-value is about 2 (13). This material is

chemically stable in a reducing atmosphere, such as a hydrogen atmosphere.

marinite-calcium-silicate board - This material

contains molten metal and is machinable. [The density

ranges from 560 to 960 kg/m^ (35 to 60 lb/ft^).] At a temperature of 94°C (200°F), its X-value is 0.16 (1.1);

at 320°C ( 600°F) , X is 0.17 (1.2), and at 540°C

(1000°F), X is 0.18 (1.24)]. Thus, the X-value is

fairly constant over the density range. This material

is used at temperatures below 980°C (1800°F).

2-8
With regard to the high-temperature refractory insulations just discussed, the

manufacturer recommended a number of SRM's at various densities. These were 96

270, 640, 1300, 1900, 2600 kg/m3 (6, 17, 40, 80, 120, and 160 lb/ft 3 ). The

reason given was that the X-value curve as a function of temperature depends

of the density, and it would be useful to have more interpolation points.

13. Micropore International Limited

Contact Person: John Hughes, Marketing Manager

Hadzor Hall, Hadzor

Droitwich, Worcs., WR9-7DJ, England

(0905 774211)

This firm produces a product called Microtherm which shows promise as a calibration material over a wide range of temperature. There is no reason

that it could not be used down to cryogenic temperatures, although there was

no experience here, and it could be used at temperatures up to 1000°C (1832°F).

The material consists of a microporous mixture of silica and ceramic powders.

It contains titanium dioxide for opacification and ceramic fiber for reinforcement. This material is produced over a density range of 192 to 384 kg/m3

(16 to 24 lb/ft 3 ), although it is usually produced at 240 kg/m 3 (15 lb/ft 3

).

The X-value varies only a few percent over this density range. For this

reason, the X-value is expected to be extremely uniform over the area of a specimen, between specimens in a lot (better than 1 percent), and between lots

(better than 5 percent). It comes in thicknesses between 3 and 51 mm (0.125

and 2 in). This material is similar to the Min-K product just discussed in

item 12 (produced by the Manville Services Corporation), and its dependence on atmospheric pressure was estimated to be comparable. The X-value at 24°

C

(75°F) is 0.02 W/m*K (0.14) and at 500°C (932°F) is 0.032 W/m*K (0.22).

The latter point is measured with a temperature difference of approximately

800°C (1440°F). The ratio of X-value in the direction across the specimens

to that in the direction parallel to the surface is 0.88. The material is

produced in a block form, in which case the surface is chalky and not very

durable. It is also produced in panel form, covered with glass cloth, in

which case it is very durable. There are flexible and quilted versions of the

panel form.

Microtherm is used in industry for the insulaton of ovens, furnaces, pipework,

aircraft and nuclear power installations as well as in domestic equipment such

as ranges and microwave ovens. The thickness of Microtherm required is

generally one-third the thickness needed using alternative insulation materia 1^

2-9
14. Owens-Corning Fiberglass Corporation (OCF)

Contact Person: Ron Adams

Box A15

Granville, OH 43023

(614) 587-7048

OCF produces and tests the following materials :

Product Type Thickness Density Tm Apparent Thermal Conductivity

cm in kg/m^ lb/ft^ °C °F W/m»K Btu*in/ft2»hr*F

Calcium Silicate 3.8 1.5 208 13.0 66 150 0.063 0.44

138 280 0.055 0.38

233 450 0.061 0.42

333 630 0.074 0.51

4.1 1.6 141 8.8 71 160 0.046 0.32

94 200 0.046 0.32

121 250 0.049 0.34

158 315 0.055 0.38

266 510 0.072 0.50

360 680 0.089 0.62

Air Craft Insulation 3.8 1.5 13 8.8 99 210 0.048 0.33

(fine glass-fiber) 205 400 0.078 0.54

310 590 0.113 0.91

16 1.0 24 75 0.032 0.22

99 210 0.043 0.30

216 420 0.069 0.48

327 620 0.113 0.78

(Excellent homogeneity. Very hygroscopic.)

Wood Fiber Sheathing 1.3 0.5 288 18 24 75 0.055 0.38

52 125 0.056 0.39

Duct Board 2.54 1.0 66 4.1 24 75 0.033 0.23

55 130 0.036 0.25

Glass-Fiber for 2.54 1.0 67 4.2 24 75 0.030 0.21

Industrial 49 120 0.033 0.23

Insulation 94 200 0.039 0.27

121 250 0.043 0.30

TIW 5.1 2.0 35 2.2 24 75 0.033 0.23

Aercor-Black 1.9 0.75 24 1.5 24 75 0.033 0.23

Navy Board 5.1 2.0 43 2.7 24 75 0.032 0.22

2-10
Product Type Thickness

cm in

Density

kg/m3 lb/ft 3

f

°C

^m

°F

Apparent

W/m*K

Thermal Conductivity

Btu* in/ft 3 * hr •

F

Aercor Aircraft Ins. 2.54 1.0 10 0.6 24 75 0.035 0.24

1.9 0.75 24 1.5 24 75 0.030 0.21

Polyisocyanurate

Foam 1.3-10.2 - .5-4.0 30 1.9 24 75 0.020 0.14

P 80 Molded 80 5.0 24 75 0.033 0.23

208 13.0 24 75 0.036 0.25

272 17.0 24 75 0.039 0.27

336 21.0 24 75 0.046 0.32

(Very stable and homogeneous .)

Roof Insulation 5.1 2.0 117 7.3 24 75 0.035 0.24

3.2 1.25 125 7.8 24 75 0.033 0.23

3.2 1.25 93 5.8 24 75 0.033 0.23

3.3 1.3 122 7.6 24 75 0.036 0.25

MB I 10.2 4.2 16 1.0 24 75 0.040 0.28

8.9 3.5 18 1.1 24 75 0.039 0.27

7.6 3.0 21 1.3 24 75 0.038 0.26

7.6 3.0 9 0.6 24 75 0.048 0.33

7.6 3.0 12 0.7 24 75 0.043 0.30

7.6 3.0 8 0.5 24 75 0.049 0.34

OCF has tested, but does not produce the following other materials

:

Product Type Thickness Density Tm Apparent Thermal Conductivity

cm in kg/m3 lb/ft 3 °C °F W/m»K Btu* in/f

t

2 • hr •

F

Matted Glass Fibers 2.54 1.0 147 9.2 83 180 0.045 0.31

133 270 0.051 0.35

183 360 0.058 0.40

199 390 0.061 0.42

(Candidate for high-temperature SRM.

)

Microspheres 3.8 1.5 62 3.9 21 70 0.027 0. 1

9

(Fumed Silica) 49 120 0.033 . 77 170 0.045 0. 31

88 190 0.049 0. 34

96 204 0.055 0.38

2-11
Product Type Thickness Density Tm Apparent Thermal Conductivity

cm in kg/m3 lb/ft 3 °C °F W/m*K Btu*in/ft 3

Open-Cell Phenolic

Foam 3.6 1.4 34 2.1 24 75 0.035 0.24

Rockwool Mineral 2.54 1.0 67 4.2 26 78 0.035 0.24

Fiber 127 260 0.052 0.36

141 8.8 24 74 0.036 0.25

121 250 0.050 0.35

196 385 0.066 0.46

Mineral Fiber 7.6 3.0 26 1.6 24 75 0.040 0.28

Fibair Filter Media 7.6 3.0 3.2 0.2 24 75 0.125 0.87

6.4 2.5 3.8 0.24 24 75 0.113 0.78

5.1 2.0 5 0.31 24 75 0.097 0.67

3.8 1.5 6.6 0.41 24 75 0.081 0.56

expanded polystyrene 7.4 2.9 - — 24 75 0.038 0.26

0.039 0.27

Truck Decking 2.8 1.1 880 55.0 23 73 0.173 1.20

Vinyl Flooring

Material - - - - 24 75 0.100 0.69

0.082 0.57

Down 2.54 1.0 - - 24 75 0.040 0.28

Thinsulate 200 1.4 0.55 - - 24 75 0.036 0.25

Felted Ceramic

Fiber 1.3-10.2 0. 4-4.0 288 18 94 200 0.062 0.43

205 400 0.075 0.52

323 600 0.086 0.60

427 800 0.107 0.74

538 1000 0.121 0.84

649 1200 0.141 0.98

760 1400 0.166 1.15

871 1600 0.188 1.30

(Possible candidate for a high-temperature standard.)
15. Rmax, Inc.

Contact Person: Amy Ely

13524 Welch Road

Dallas, TX 75234

(214) 387-4500

Product Type - Polyisocyanurate [X-value is approximately 0.021 (0.145).

16. Rockwool Industries, Inc.

Contact Person: Jesse Bridwell

7400 South Alton Court

Englewood, CO 80112

(303) 733-6200

Product Type 1 - blown mineral wool [X-value at a temperature of

24°C (75°F) and a density of 27 kg/nH (1.7 lb/ft^) is

0.048 (0.33).]

Product Type 2 - mineral wool blanket [X-value ranges from 0.036

to 0.049 (0.25 to 0.34) at a temperature of 24°C

(75°F) and a density range from 19 to 40 kg/m^

(1.2 to 2.5 pcf).]

17. Texaco Chemical

Contact Person: David McCoy

P.0. Box 15730

Austin, TX 78761

(512) 459-6543

Product Type - polyurethane foam [X-value ranges from about 0.023

to 0.025 (0.16 to 0.17).]

18. The Upjohn Company, CPR Division

Contact Person: Robert Pilmer

555 Alaska Avenue

Torrance, CA 90503

(213) 320-3550

Product Type - polyurethane, polyisocyanurate, and polycarbanilide

foamed plastics [X-value of about 0.023 (0.16) for

the first two and 0.039 (0.27) for the latter.]

19. W. R. Grace

Contact Person: Robert Orlandi

62 Whittemore Ave.

Cambridge, MA 02140

(617) 876-1400

Product Type 1 - polystyrene (expanded) [At 5°C (40°F) the X-value

is about 0.036 (0.25); density 16 kg/m^ (1.0 lb/ft*).]

It is produced in 25 to 200 mm (1 to 8 in) thicknesses.

2-13
Product Type 2 - insulating cement [The X-value is 0.097 (0.67) at

24°C (75°F); the density ranges between 350 and 450

kg/m3 (22 to 28 lb/ft 3 ).]

Product Type 3 - vermiculite [At a temperature of 24°C (75°F) the

X-value is about 0.056 (0.39) for the density value

of 95 kg/m3 (5.9 lb/ft3 ).]

20. Whirlpool Corporation

Contact Person: David Valentine

850 Arcade Street

St. Paul, MN 55164

(612) 778-2372

Product Type 1 - polyurethane foam [X-value of about 0.025 (0.17).]

Product Type 2 - glass-fiber [X-value of approximately 0.049 (0.34).]

2.1.2. Microsphere Manufacturers

1. Degussa Corporation

Contact Person: Pat Linard

P. 0. Box 2004

Teterboro, NJ 07608

(201) 288-6500

A fumed silicon-dioxide micro-powder material called aerosil is produced over a size of 7-50 milli-microns . Information from the University of California,

Berkeley, indicated that the X-value of a "cake layer" of 7 milli-micron material was 0.020 W/m*K (0.14). In addition to the fumed silicon-dioxide material, an amorphous silicon-dioxide material and a precipitated silica material are produced.

It is possible to make the powders hydrophobic by a chemical treatment.

2. P. Q. Corporation

Contact Person: John Peters

P. 0. Box 258

Lafayette Hill, PA 19444

(215) 825-5000

This company produces microspheres of various materials, such as silica,

borosilicate glass, and alumina-silicate glass. These microspheres are hollow

and have wall diameters from 1 to 2 pm. The range of diameters is 10 to 180 pm; a X-value range from 0.043 to 0.089 W/m»K (0.30 to 0.62) was reported.- The material

can be produced to be hygroscopic or hydrophobic.

2-14
2.2 Testing Laboratories

1. Cal-Coast Laboratories

Contact Person: Mike Fairley

P. 0. Box 2044

Berkeley, CA 94702

(415) 540-7837

They plan to test a layered industrial insulation between temperatures of 0 to

300°C (32 and 570°F). They are not certain of the X-value for this proposed

project

.

2. Dynatech R & D Company

Contact Person: Andre Desjarlais

99 Erie St.

Cambridge, MA 02139

(617) 868-8050

This testing laboratory makes thermal measurements over almost the entire

range of materials, X-values and temperatures. The following is a sample of

the products they have tested.

Product Type 1 - high- temperature glass fiber - At a temperature of

24°C (75°F), this 50 kg/m^ (3 lb/ft^) material has a X-value of about 0.040 (0.28); at 94°C (200°F) it is

0.052 (0.36); and at 200°C (400°F) it is 0.072 (0.50).

Product Type 2 - mineral fiber - At a temperature of 24 °C (75 °F) this

mineral fiber has a X-value of 0.036 (0.25); at 94°C

(200°F) a 96 kg/m^ (6 lb/ft^) product has a X-value

of 0.046 (0.32); and a 192 kg/m^ (12 lb/ft^) product

has a X-value of 0.048 (0.33).

Product Type 3 - refractory insulation - At a temperature of 430°C

(800°F), it has a X-value of about 0.115 (0.80).

Product Type 4 ceramic fiber - This product has a X-value of 0.039 (0.27).

Product Type 5 - non-woven glass fiber - At a density value of about

160 kg/m^ (10 lb/ft^) and a temperature of 150°C

(300°F), this material has a X-value of 0.079

(0.55) and at 370°C (700°F) a X-value of 0.108 (0.75).

Product Type 6 - zirconia fiber - This material can be used at temperatures up to 1650°C (3000°F). It has a density range

between 96 to 1600 kg/m^ (6 to 100 lb/ft^). Its X-value

at room temperature is about 0.087 (0.60).

2-15
Product Type 7

Product Type 8

Product Type 9

Product Type 10

Product Type 11

Product Type 12

Product Type 13

Product Type 14

Product Type 15

Product Type 16

Product Type 17

Product Type 18

insulating cement (filled with vermiculite or perlite) - This material is produced over a density range of

320 to 2200 kg/m^ (20 to 140 lb/ft^). At the low end

of the density range it acts like a fiber board

material in terms of its X-value curve as a function

of temperature; and at the higher densities it acts

as a ceramic insulating material. At 24°C (75°F)

the X-value varies from 0.098 to 0.159 (0.68 to 1.1).

calcium silicate [X-value of about 0.058 (0.40).]

polyurethane [X-values range between 0.023 and

0.025 (0.16 to 0.17).]

phenolic foam - This foam material has a X-value of

about 0.025 (0.17) at a temperature of 24°C (75°F).

microsphere and epoxy foam [X-value of 0.3 (2).]

gum rubber [X-value of 0.16 (1.1).]

glass fiber - This type glass fiber has been tested

up to 450°C (850°F). [X-value of 0.3 (0.042) at

24°C ( 75°F) .

]

mineral fiber - This type mineral fiber has been

tested up to 1040°C (1900°F). [X-value of 0.042

(0.29) at 24°C (75°F).]

Pyrex 7740 is a glass material of 13 mm (0.5 in)

thickness having a X-value of approximately 1.0

(7.0). This product was produced by Corning.

polycrystalline ceramic (Pyro Ceram) - This material

is produced in 25 mm (1 in) diameter rods and

13 mm (0.5 in) thick plates. At a temperature of

24°C (75°F) the X-value is approximately 2.88 (20);

and at 150°C (300°F) it is about 2 (15).

foam glass - This material can be used at temperatures

up to 480°C (900°F). At a temperature of 24°C (75°F)

the X-value is approximately 0.05 (0.35); at 260°C

(500°F) it is 0.1 (0.7), for a density of approximately

112 kg/m3 (7 lb/ft^).

Teflon, Rayon and Epoxies - These materials all have

a X-value at a temperature of 24°C (75°F) of about

0.22 (1.5).

2-16
3. Dynatherm Engineering

Contact Person: James B. Funkhouser

595 Marshan Lane

Lino Lakes, MN 55014

(612) 786-1853

Product Type 1 Thermax board - [A-value 0.022 (0.15) at temperatures

between -17 to 74°C (0 to 165°F).]

Product Type 2 - extruded polystyrene - [A-value of about 0.026

(0.18) at temperatures between -17 to 74°C (0 to

165°F).

]

Product Type 3 - expanded polystyrene - [A-value about 0.036

(0.25).]

Product Type 4 - expanded urethane - [A-value about 0.022 (0.15).]

Product Type 5 - wood fiber board - [A-value about 0.072 (0.5).]

Product Type 6 - perlite [A-value ranges between 0.039 and 0.058

(0.27 and 0.40) for loose-fill perlite and between

0.072 and 0.134 (0.50 and 0.93) for concrete perlite.]

Product Type 7 - vermiculite [A-value ranges between 0.048 and

0.059 (0.33 and 0.41) for loose-fill vermiculite and

between 0.085 and 0.139 (0.59 and 0.96) for concrete

vermiculite.

]

Product Type 8 - fiber-glass blanket and board material [A-value

ranges between 0.035 and 0.050 (0.24 and 0.35) at

24°C ( 75°F) .

]

Heat-Transfer Apparatus - Guarded-Hot-Box.

4. Energy Materials Testing Laboratory (EMTL)

Contact Person: Mr. Lagedrost

Bidderford Industrial Park

Bidderford, ME 04005

(207) 282-5911

Product Type 1 - carbon fiber [A-value ranges between 0.1 and 4

(0.7 and 28) at 24°C (75°F).]

Product Type 2 - graphite [A-value about 2 (14) at a temperature

of 24°C (75°F) and 0.3 (2) at high temperatures.]

Product Type 3 - ceramics [A-value of about 4.3 (30).]

Heat-Transfer Apparatus - a Guarded-Hot-Plate and comparative

measurements equipment.

2-17
EMTL measures all thermal properties on nearly all classes of solids, over the

temperature range from below room temperature to 2760°C (5000°F). In the

specific area of thermal conductivity, they have worked with materials having

A-values between 0.10 (0.7) and 300 (2080). The lower part of this range is

usually evaluated with a steady-state technique (absolute or comparative) in

the range up to about 1000°C (1832°F). For most materials and for most classes

of solids with moderate to high A-values and at the higher temperatures, they

use a transient technique (laser pulse) to measure thermal diffusivity, from

which thermal conductivity can, in most cases, be calculated.

For reference standards, they use those materials currently available. However,

they feel a real need for standards in the moderate to low A-value range,

which can be used up to higher temperatures (1600°C or 2912°F). Their apparatus

can operate at these temperatures, but the large mis-matches in A-values of

the specimens and the existing standards result in a potential for large errors.

5. Hauser Laboratories

Contact Person: Rod McKeever

5680 Central Ave.

P. 0. Box G

Boulder, CO 80306

(303) 443-4662

Product Type 1 - glass fiber [A-value of 0.049 (0.34) for lowdensity glass fiber and between 0.032 and 0.036

(0.22 and 0.25) for high-density glass fiber.]

Product Type 2 - loose-fill [A-value of about 0.046 (0.32).]

Product Type 3 - cellulose products [A-value ranges between

0.039 and 0.045 (0.27 and 0.31).]

Heat-Transfer Apparatus - Heat-Flow-Meter (tests at room temperature)

Hauser Laboratories would like to have transfer standards available at

different temperatures for building applications.

6. Law Engineering Testing Company

Contact Person: Mr. John Lynch

P. 0. Box 13260

Atlanta, GA 30324

(404) 873-4761

Product Type - concrete [A-value of approximately 0.35 (2.4) for

cinder concrete, and of 1.21 (8.4) for stone concrete.]

7. Multi-Tech Corporation

Contact Person: Dr. Ralph Goldman

1 Strathmore Road

Natick, MA 01760

(617) 651-1030

Product Type 1 - materials for insulating and clothing applications

2-18
are tested using a heated flat plate to determine

their R-value or clo-value.

Product Type 2 - materials, films and membranes for clothing applications

are tested for their moisture permeability using a heated, sweating flat plate.

Product Type 3 - clothing items are tested for their insulation and

permeability using a heated, sweating life-size

manikin which can be operated still or walking.

Product types tested include: conventional and reflective insulations,

PVC, PTFE, and similar waterproof but vapor permeable membranes, protective

uniforms, sports clothing, raincoats, blankets, sleeping bags, etc.

8. National Association of Home Builders

Contact Person: Hugh Angleton

627 Southlawn Lane

Rockville, MD 20850

(301) 762-4200

Product Type 1 - low-density glass-fiber [X-value ranges between

0.043 and 0.053 (0.30 to 0.37) for density range

from 6 to 16 kg/m3 (0.4 to 1.0 lb/ft 3 ).]

Product Type 2 - mineral wool fiber [ X-value ranges between 0.039

and 0.043 (0.27 to 0.30) for density of about 26

kg/m3 (1.7 lb/ft 3 ).]

Product Type 3 - foil covered polyisocyanurate [X-value ranges

between 0.014 and 0.023 (0.10 and 0.16) as the density

ranges from 24 to 32 kg/m3 (1.5 to 2.0 lb/ft 3 ).]

Product Type 4 - expanded polystyrene [X-value of about 0.040

(0.28) for a density of approximately 16 kg/m3 (1 lb/ft 3 ).]

Product Type 5 - extruded polystyrene [X-value of about 0.029

(0.20) for a density of approximately 26 kg/m3 (1.6 lb/ft 3 ).]

Product Type 6 - blown mineral wool [ X-value ranges between

0.046 to 0.065 (0.32 to 0.45) as the density ranges

from 10 to 26 kg/m3 (0.6 to 1.6 lb/ft 3 ).]

Product Type 7 - wood fiber board [X-value of about 0.055 (0.38);

density of about 352 kg/m3 (22 lb/ft 3 ).]

2-19
9.

Technical Microns Control, Inc.

Contact Person: Mrs. Kathy Clayton

P. 0. Box 1330

210 Synn Drive

Huntsville, AL 35805

(205) 837-4430

Product Type - loose-fill cellulose [X-value of about 0.040 (0.28);

density of 46 kg/m^ (2.9 lb/ft^).]

10. Underwriters Laboratories, Inc.

Contact Person: Bob Kingsbury

333 Pfingsten Road

Northbrook, IL 60062

(312) 272-8800

Product Type 1 - loose-fill cellulose [X-value ranges between 0*039

and 0.042 (0.27 and 0.29), density ranges between 32

and 48 kg/m^ (2 and 3 lb/ft^).]

Product Type 2 - high-density polystyrene [X-values range from 0.024

to 0.037 (0.17 to 0.26) at a nominal thickness of

25.4 mm (1 in) and over a density range from 32 to

56 kg/m^ (2.0 to 3.5 lb/ft^).]

Heat-Transfer Apparatus - Heat-Flow-Meter

UL is interested in having a standard at their conductivity and thickness test

conditions.

11. United States Testing Co., Inc.

Contact Person: Bob Manno

1415 Park Avenue

Hoboken, NJ 07030

(201) 792-2400

Product Type 1 - loose-fill cellulose [X-value ranges from 0.039

to 0.046 (0.27 to 0.32).]

Product Type 2 - glass-fiber blanket insulation [X-value ranges

between 0.035 and 0.050 (0.24 to 0.35) at 24°C (75°F).]

Product Type 3 - polyurethane [X-value of approximately 0.026 (0.18).]

Product Type 4 - polystyrene [X-value of approximately 0.033 (0.23).]

2-20
2.3 Universities [22]

1.

Carnegie-Mellon University

Pittsburgh, PA 15213

Contact Person: Dr. Yao

(412) 578-2508

Carnegie-Mellon does research on multi-phase heat transfer in connection with

boiling phenomena. Work is conducted on droplet and spray combustion which

could have an application in coal slurry work, and interest was expressed in

X-values of various metal alloys at very high temperatures and of fluorocarbons

near critical temperatures. Another issue is the determination of the surface

emittance at these test conditions. An area of research dealing with combustion

requires the use of estimated thermal conductivity values of various mixtures

of fuel from handbook sources, and these do not have the desired accuracy.

2. Clemson University

Clemson, SC 29631

Contact Person: Dr. Bishop

(803) 656-3201

Dr. Bishop conducts research in the area of natural convection in horizontal

cylindrical annuli at low-temperature (down to liquid nitrogen temperature).

The medium is helium gas and the annulus pressure can be varied from low

vacuum to 1724 kPa ( 250 psi). A maximum Rayleigh number of about 10 12 can be achieved in the apparatus. The apparatus can also operate at high values

of the temperature difference ratio, and thus, the effects of variable transport

properties can be studied. Accurate values of the thermal conductivity of

helium over a temperature range of 77 K to 280 K are required. Additional

researchers are working on droplet evaporation and f luidized-bed heat transfer.

3. Cornell University

Ithaca, NY 14853

Contact Person: Dr. Torrance

(607) 256-6253

Cornell University conducts research on the thermal properties of composites,

such as solids/liquids or two solids (e.g. glass beads in water or in air).

Another interest is geothermal studies. An apparatus was fabricated

to measure thermal diffusivity, and this device uses a glass product from

Corning-Glass for calibration purposes.

In the Chemical Engineering Department at Cornell University, Paul Steen does

theoretical work on convection in porous materials.

2-21
4. Iowa State University

Ames, IA 50011

Contact Person: Dr. Martin

(515) 294-3344

Dr. Martin conducts research on plane periodic thermal waves; for example, the

sun's radiation onto the earth creates a daily variation that can be sensed within

a depth of 1 m below the earth's surface and a yearly variation which can be

sensed within a depth of about 16 m into the earth. Experiments are carried

out on bricks, and Fourier analysis results have shown that the drop off of

intensity for higher harmonic is very rapid. For example, the first harmonic

is only 0.4 percent of the fundamental frequency intensity. This university

has also done research on refractories at temperatures as high as 1650°C (3000°F),

but more typical temperatures lie in the 870°C (1600°F) range.

5. Massachussetts Institute of Technology (MIT)

Cambridge, MA 02139

Contact Person: Dr. Glicksman

(617) 253-2233

MIT has investigated polyurethane and phenolic foams in terms of coupled

conduction and radiation heat transport. Research is oriented to the

measurement of radiation scattering and the modeling of heat transfer on a microscopic level — taking into account the actual structure of the insulation

material. Studies were conducted on moisture phenomena in expanded polystyrene

in terms of water vapor diffusion and condensate spreading. This research

showed an increase of about 10 percent in \-value with moisture. Measurements

were made of the A-value of the solid polymers used in insulation foams.

That is, the crushed material which actually forms the cell structure, such as polyisocyanurate or polyurethane, was measured. The X-values varied between

0.17 and 0.26 (1.2 and 1.8).

6. Purdue University

School of Mechanical Engineering

West Lafayette, IN 47906

Contact Person: D.P. DeWitt

(317) 494-5629

Purdue University researchers have done extensive work on high-temperature

radiation heat transfer and thermophysical properties. Present activities

include measurement of spectral emissivity from 600 to 1200 K and 0.6 to 12 pm.

Simultaneous heat and moisture transport processes in the normal environmental

temperature range are being experimentally studied using a calibrated, ASTM-hotbox apparatus. Purdue maintains a close association with the Center for Information

and Numerical Data Analysis and Synthesis (CINDAS) which is a data base resource

for thermophysical properties of materials.

2-22
7. Rutgers University

New Brunswick, NJ 08903

Contact Person: Dr. Yaluria

(201) 932-3652

Rutgers University researchers are interested in natural and forced convection

flow in air or water. The researchers have collaborated with NBS and with the

Solar Energy Research Institure (SERI) in such studies. They are particularly

interested in knowing the temperature dependence of the X-value for materials

such as polystyrene or masonite in the temperature range associated with building materials.

8. University of California

Berkeley, CA 94720

Contact Person: Professor Tien

(415) 642-7540

Professor Tien is paricularly interested in radiation contributions. For

example, his group does calculations for radiation shielding in furnace chimneys

for a temperature range between 540 and 1100°C (1000 and 2000°F). A practical

application of this work is the reduction of the refractory wall temperature

by about 40°C (100°F). In addition, his group does first principle calculations of

radiation transport in ambient temperature fiber-glass for high and low temperatures.

They have done some research on the 70 to 80 A diameter microspheres from the

Degussa Corporation and found the X-value to be approximately 0.020 (0.14).

9. University of Delaware

Newark, DE 19711

Contact Person: Prof. Frank Kulacki

(302) 451-2421

Professor Kulacki conducts research on convection in porous medium. For example,

he looks at borosilicate glass beads in liquids, and needs to know the X-value

of glass and of metals. In addition, he investigates composites, such as glass

or carbon fibers and epoxies, and it is necessary to know the thermophysical

properties up to temperatures of 260°C (500°F). In the case of aluminum fiber

or boron ceramics, the high temperature limit is about 800°C (1500°F). Dr. Kulacki

indicated that there is very little data for such thermophysical properties

at high temperatures. The aerospace industry has collected data, but this is

usually considered proprietary. Additional data are needed on the thermophysical

properties at high temperatures. He is designing a test facility to do

high-temperature work, so that such data will be available in the public domain.

10.

University of Illinois

1206 W. Green, Rml 68-MEB

Urbana, IL 61801

Contact Person: Dr. Richard Buckius

(217) 333-1079

Dr. Buckius is interested in radiation heat transfer and the combustion

process, solar applications, and fluidized bed studies. Previously, he has

done work on radiation transfer in gas and particulate mixtures, In fibrous

2-23
materials and in microspheres. Experimental infra-red research provided data

on radiation scattering properties in a pure particulate medium. He has also

modeled coal-air mixtures used in coal combustion.

11.

University of Massachusetts

Amherst, MA 01003

Contact: Dr. William P. Goss

(413) 545-2037/2505

The Thermal Measurements Laboratory has a calibrated hot box and a guarded hot

plate (now being fabricated). The calibrated hot box has recently been used to

measure the thermal transmittances of reflective building insulation systems

and window treatment products. The present calibration samples used are high

density, glass-fiber boards (2 and 4 inches) and expanded polystyrene board

(2 and 4 inches). There is an interest in obtaining low to high thermal

conductance standards in the range of thicknesses of 0.5 to 4 inches for use in

calibration of the hot box and of the window mask walls in the temperature

range -17.8 to 65.6°C (0 to 150°F).

12. University of Mississippi

University, MS 38677

Contact Person: Dr. Alley Smith, Dr. Jeff Roux

(601) 232-7407

(601) 232-5375

The University of Mississippi research includes both work on radiation transfer

through fibrous insulation material and the measurement of reflectance using

integrating spheres. They have been modeling this transport process using a discreet ordinate technique and assuming a plane-parallel layer for the binder.

They have also been studing innovative layered materials.

13. University of Oklahoma

Norman, OK 73019

Contact Persons: Tom Love and Will Sutton

(405) 325-5011

Dr. Love's research deals with the experimental determination of the extinction

coefficient and the albedo for fiber insulations. He uses integrating spheres

to determine the diffuse transmittance and reflectance. He is interested in

looking at foam insulation and insulations in vacuum as well. He has done

some other work on multi-dimensional radiation scattering for high-temperature

ceramic materials.

14. University of Pennsylvania

Philadelphia, PA 19104

Contact Person: Dr. Bau

(215) 898-8363

The University of Pennsylvania conducts research on multi-phase porous medium,

such as glass beads and liquids. This simulates physical phenomena in soils.

They are also interested in natural convection in porous and non-porous media.

2-24
15. University of Washington

Seattle, WA 98195

Contact Person: Dr. Corlett

(206) 543-8590

Dr. Corlett conducts research on underground coal gasification, and would like

to know the X-value for materials at all stages in this process.

Contact Person: Dr. Emery

(206) 543-5338

Dr. Emery has done studies involving radiation heat transport in high-temperature

materials such as the space shuttle tile and ceramics. The temperatures

of interest include 0 to 310 K (-460 to 100°F) and, for applications such as re-entry of space vehicles into the Earth atmosphere, 1300°C (2370°F). In the area of building insulation there is an interest in the problem of moisture

phenomena in reflective foils, as well as in problems of slab-on-grade heat

transfer, and this requires knowledge of the X-value of soil. They are particularly

interested in knowing the thermal dif fusivities of the materials involved in

their research.

16. Virginia Polytechnical Institute

Blacksburg, VA 24061

Contact Person: William Thomas

(703) 961-7464

VPI research has investigated the use of a transient thermal technique using a thermistor probe to determine moisture content by measuring the X-value of moist

glass-fiber insulation specimens. An interest was expressed in calibration points

between 0.045 to 0.30 (0.31 and 2.1).

2.4 Federal Laboratories [11]

1. Naval Oceanographic Research & Development Agency

Contact Person: James Elkins

Bay St. Louis, MS 39529

(601) 688-4702

The agency is interested in X-values of titanium steel, glass fiber, epoxies,

thinsulite (diving suit), and teflon and neoprene rubber for temperatures ranging

between -56 and 1100°C (-70 and 2000°F), depending on the application.

2. Naval Weapons Center

Contact Persons: Dr. Jim Baldwin, Mr. J.P. Newhouse

China Lake, CA 93555

(619) 939-7392

The Naval Weapons Center has a high-temperature calorimeter apparatus to measure

the heat flux of flames. They are interested in a new insulation system for r ramjet applications. The temperature is estimated to be about 2800' C (50<" f- ;

.

2-25
They have investigated a material called DC93104, produced by Dow Corning.

This is a silica reinforced rubber with a carbon fiber in it. The high-temperature

exposure converts the rubber to a carbon-fiber filled char. The X-value at

40°C ( 100°F) is about 0.039 (0.27), and at 820°C (1500°F) it is about 0.043 (0.30).

Contact Person: Charles Beach

(619) 939-7392

Research is conducted on materials such as epoxy and special cork insulators

at temperatures up to 200°C (400°F). They are interested in using these materials

to protect electronics in aerospace applications. The hot- and cold-side temperatures might be 370°C (700°F) and 74°C (165°F). They also look at ablated

coatings as a way to keep the temperatures of the electronic equipment low.

Contact Person: Kent Farmer

(619) 939-7225

Mr. Farmer is doing research on fire in airplanes. He is interested in materials

that provide thermal protection. A deck fire can involve temperatures up to

1300°C (2300°F). An extensive study is beginning on the following types of

materials. This study will include the characterization of these materials

according to their thermophysical properties, such as X-value.

(1) ceramic clothes

(2) insulating foams

(3) intumescent paints

(4) high-temperature silicone based corks

(5) honeycomb materials such as fiber-phenolic for high- temperature

applications and hybrids of these with other types of materials.

(6) ablative (phase-change) materials such as tar coating

(7) selective emissivity materials which would irradiate heat

selectively for the temperature range of use

(8) microspheres, both by themselves and in hybrid with other

materials such as rubber

(9) adhesive systems

(10)

thermal barrier, such as high-temperature polystyropolodeens

or silicon carbide.

Contact Person: Dick Compton

(619) 939-2866

The research includes aerodynamic heating of missiles in flight. It is done

with a propane torch and a wind tunnel. The X-value is a parameter in their

studies, and for the most part they use the data resources listed in references

[13, 14, and 15]. They consider materials such as ceramics, various composites,

pyro ceram, explosives and propellants, adhesives (they are specially interested

in the X-value of these materials), and silicone rubber. They are very

interested in radiation properties, such as emissivity, of materials in the

temperature range between 800 and 1400°C (1500 to 2500°F).

2-26
3. Clothing and Textile Research Facility (Navy)

Contact Person: Joe Gible

Natick, MA 01760

(617) 651-4740

The Navy has a guarded-hot-plate with a sweating feature to determine vapor

permeability. Measurements are made of the A-value and the permeability for

a wide range of clothing.

4. Natick R & D Laboratory

Contact Person: Deirdre Rapacz

Natick, MA 01760

(617) 651-4273

Measurements are made of the thermal transport properties of materials utilized

in cold weather clothing applications, including various denier polyester and

polyolefin fibrous battings, down, needled felts, foams, fleeces and apparel

fabrics. The A-values range from 0.032 to 0.110 (0.13 to 0.77), and the density

ranges from 4.8 to 292 kg/m^ (0.30 to 18 lb/ft^). A guarded-hot-plate and a heat-flow-meter apparatus are utilized with the hot-plate temperature maintained

at 33°C (92°F). Also, a bi-guarded hot plate with a sweating feature is used

to determine the moisture vapor permeability index of textiles.

5. U.S.A. Cold Regions Laboratory (Army)

Contact Person: Steve Flanders

72 Lyme Road

Hanover, NH 03755

(603) 646-4302

The Cold Region Laboratory conducts building-system investigations using a calibrated hot box; thus they need to know the A-value for standard building

materials, such as insulation and wood. They have a guarded hot plate and two

heat flow meters. Their soils research requires the use of these apparatus

for thermal measurements. They have also done some work on moist solids.

2.5 Department of Energy

1. Lawrence Berkeley Laboratory (LBL)

Contact Person: Michael Rubin

University of California

Berkeley, CA 96720

(415) 486-7124

Dr. Rubin has conducted research on silica aerogel, which is the 100 £ material

produced by the Degussa Corporation. LBL has made it into cakes using a gel

and extracting the solvent super-critically. The A-value is about 0.020

(0.14); also, this material can be used at high temperatures. It can also be

used for window insulation because there is very little scattering of the

visible radiation, and, hence, the material is transparent. There is n need to

measure the A-value of thin films on plastic, for application as an infra-red

reflecting heat mirror.

2-27
2. Lawrence Livermore National Laboratory

Contact Person: Bob Trusty

P.0. Box 808 L-145

Livermore, CA 94550

(415) 422-7401

This laboratory has tested specimens over a X-value range of 0.030 to 4.76

(0.21 to 33). This includes polyurethane, foams, plastics, composites,

aluminum-honeycomb material, ebonite, metals, and graphite. The tests are carried out on a 4-inch guarded hot plate, a thermal comparator (for higher

X-values), and a 1.06 ym laser, flash diffusivity device (for the metals).

The thermal comparator requires calibration specimens over a wide range of X-value.

A concern was expressed over calibration-standard, material variability errors caused by forming the standard material into the sizes and shapes required by

different testing stations. In addition to making thermal diffusity measurements,

they make thermal expansion, specific heat, and density measurements on many

materials

.

3. Oak Ridge National Laboratory

Contact Person: Dave McElroy

P. 0. Box X

Oak Ridge, TN 37830

(615) 574-4193

Testing is done over a wide range of X-value and temperature with a number

of apparatuses. In addition to testing typical building insulation such as glass-fiber at high and low densities, mineral-fiber, expanded polystyrene and

blown-wool, there is a current effort to study evacuated panels which have an effective X-value of 0.009 (0.06) at a thickness of 50 mm (2 in). They have

tested a fiber-board material with a X-value of about 0.072 (0.5) and a density of 320 kg/m^ (20 lb/ft^). They have tested about 20 loose-fill

powders. At 24°C (75°F), a 7 milli-micron micro-powder was found to have

a X-value of 0.021 (0.146), and a 12 milli-micron one had a X-value of

0.020 (0.139). An amorphous silica microsphere with a diameter of about 1 ym

had a X-value of about 0.03 (0.21), and a coarse alumina loose-fill material

had a X-value of 0.28 (1.94). They have tested a high-temperature carbon-fiber

insulation. The X-value ranges between 0.1 and 4 (0.7 and 28) at 24°C

(75°F); and, it can be used at temperatures up to 930°C (1700°F). They

plan to test an alumina fiber (X-value of about 0.033 (0.23) for

temperatures between 24 and 930°C (75 and 1700°F).

The following areas of need for standards were emphasized: thermal diffusivity

(including specific heat and density data), thermal expansion, and radiation

transport properties such as the emissivity, the extinction coefficient, and

the absorption and scattering coefficients. These were considered to be

necessary for an adequate description of real or practical applications.

2-28
4. Sandia National Laboratory

Albuquerque, NM 87185

Contact Person: Ron Hadley

(505) 844-3449

Tuff volcanic rock has been examined as a candidate medium for nuclear

waste storage. The dry material has a X-value of approximately 1 (7) at

60°C (140°F). The X-value as a function of moisture content is of interest.

Contact Person: Marvin Moss

(505) 844-7307

Sandia has a number of instruments for the measurement of the apparent thermal

conductivity of materials ranging from good insulators to pure metals. Three

of these instruments were supplied by Dynatech R/D Company: the Model TCFCM

comparator, the Model TCFGM guarded hot plate, Colora Thermoconductometer.

» The comparator covers the range X =0.1 to 100 (0.69 to 690) over temperatures

from - 196 to 850°C (320 to 1560°F). The comparator measurements are accurate

within 5-10 percent, and these rely on known conductivities of one of

four reference materials, depending on the X range covered: Pyrex 7740,

Pyroceram 9606, Inconel 718, and a pure grade of iron. The first two

products are made by Corning Glass Works.

The guarded hot plate operates in the range of X of 0.02 to 2 (0.14 to 14) over temperatures from -196 to 850°C (-320 to 1560°F). Measurements are absolute

and are considered accurate within 2-5 percent.

The Colora Thermoconductometer allows relatively rapid measurement of small

samples at 33°C (90°F), 94°C (200°F), 120°C (250°F), and 170°C (340°F). The

conductivity range is X = 0.1 to 100 (0.69 to 690). The measurement involves

the evaporation of a liquid of known heat of vaporization by means of heat

passing through the sample. The time required to distill a given quantity of

the liquid is used to calculate X. The accuracy is 5-10 percent, and it is

used for materials such as glass, adhesives and metals.

Contact person: Dr. William D. Drotning

(505) 844-7934

A Sandia-developed thermal conductivity probe is available for measurement

of the X-value of liquids, powders, porous solids and other low-conductivity

materials. The instrument is useful to 1000°C (1833°F) and works best for

X £ 0.1 (0.69).

Contact Person: Dr. E. Peter Roth

(505) 844-7934

A Sandia-developed laser-flash system can measure the thermal diffunlvity

of solid materials in the temperature range 50-3000°C ( 122-54 30°F)

.

2-29

APPENDIX 3. Attendees at the Assessment Issues Work-session held at the

National Bureau of Standards on July 13, 1984.

Ron Adams Owens-Corning Fiberglas

Bill Gerken Department of Energy

David M. Greason Dow Chemical

Lee Kieffer Office of Standard Reference Materials

Edward Kifer Koppers Corporation

Dave McCaa CertainTeed Corporation

David McElroy Oak Ridge National Laboratory

Richard L. Troyer Manville Services Corporation

Ron Tye Testing Services Dynatech

Brian Rennex Center for Building Technology, NBS

Tom Faison ll il

Frank Powell II ll

3-1

APPENDIX 4. Alphabetical List of Insulating Materials in Appendix 2

APPARENT THERMAL CONDUCTIVITY*

PRODUCT NAME SI UNITS ENGLISH UNITS

OR TYPE W/m-K Btu*in/ft

Z *hr*°F

Aercor Aircraft Insulation 0.030 - 0.036 0.21 - 0.25

Aercor-Black 0.033 0.23

Air Craft Insulation

(fine glass-fiber) 0.035 0.24

Aluminum-Silicate Refractory

Fiber Insulation Blanket 0.033 0.23

Blowing Wool 0.046 - 0.065 0.32 - 0.45

Borosilicate Glass 1.042 7.14

Calcium Silicate 0.058 0.40

Cellulose 0.039 - 0.045 0.27 - 0.31

Closed-Cell Foam Glass 0.061 0.42

Concrete: cinder 0.35 2.4

stone 1.21 8.4

Down 0.040 0.28

Duct Board 0.033 0.23

Felted Ceramic Fiber 0.062 0.43

Fibair Filter Media 0.081 - 0.125 0.56 - 0.87

Foil Face Insulation 0.020 0.14

*Because of the nature of this report to assess the kinds of products that

actually in use, there will be an occasional use of a trade name or a nan i f

t c* > r. • r -

1 s name. This in no way represents an endorsement of a particular product or manufacturer. The thermal parameter values for the various insulating mater i il were obtained from the literature or from researchers. These values were n

• based on experimental research at NBS.

4-1
APPARENT THERMAL CONDUCTIVITY

PRODUCT NAME SI UNITS ENGLISH UNITS

OR TYPE W/m*K Btu*in/ft

2 *hr*°F

Glass-Fiber: low-density 0.049 0.34

high-density 0.032 - 0.036 0.22 - 0.25

Glass-Fiber Appliance

Insulation Blanket 0.035 - 0.049 0.24 - 0.35

Glass-Fiber for Industrial

Insulation 0.030 0.21

Glass-Foam 0.056 0.39

High-Density Molded Fibrous

Glass Board 0.032 0.22

Insulation Cement 0.097 0.67

Loose-Fill Mineral Fiber 0.045 0.32

Loose-Fill Cellulose 0.040 0.28

Low-Density Blanket 0.047 - 0.049 0.33 - 0.34

MBI: low-density 0.049 0.34

high-density 0.038 0.26

Matted Glass Fibers 0.045 0.31

Microspheres (Fumed Sil ica) 0.027 0.19

Mineral Fiber 0.040 0.28

Mineral Rock Board 0.043 0.30

Navy Board 0.032 0.22

Open-Cell Phenolic Foam 0.035 0.24

P 80 Molded: low-density 0.033 0.23

high-density 0.046 0.32

4-2
APPARENT THERMAL CONDUCTIVITY

PRODUCT NAME SI UNITS ENGLISH UNITS

OR TYPE W/m*K Btu*in/ft

Z *hr*°F

Perlite: loose-fill

concrete

0.039 - 0.058

0.072 - 0.134

0.27 - 0.40

0.50 - 0.93

Phenolic Foam

(closed-cell

)

0.032 - 0.136 0.22 - 0.94

Polyisocyanurate Foam 0.020 0.14

Polystyrene: extruded

mol ded

expanded

0.029

0.033 - 0.038

0.040

0.20

0.23 - 0.26

0.28

Polyurethane 0.023 - 0.025 0.16 - 0.17

Rayon 0.216 1.5

Rigidized Silica Fibertile 0.036 0.25

Rock & Slag Wool : batts

1 oose-fi 1

1

0.039 - 0.045

0.049

0.27 - 0.31

0.34

Rockwool Mineral Fiber 0.036 0.25

Silica Aerogel Composite

B1 ock 0.026 0.18

Silicone Rubber 0.245 - 0.361 1.70 - 2.50

Teflon 0.216 1.5

Thermax 0.016 - 0.020 0.11 - 0.14

Thinsulate 200 0.036 0.25

TIW 0.033 0.23

Truck Decking 0.173 1.20

Urea-Formal dehyde Foam 0.035 0.24

Vermiculite: loose-fill

concrete

0.048 - 0.059

0.085 - 0.139

0.33 - 0.41

0.59 - 0.96

4-3
APPARENT THERMAL CONDUCTIVITY

PRODUCT NAME SI UNITS ENGLISH UNITS

OR TYPE W/m*K Btu»in/ft

2 *hr*°F

Vinyl Flooring Material 0.082 - 0.100 0.57 - 0.69

Wood Fiber Board 0.056 0.39

Wood Fiber Sheating 0.055 0.38

Zirconia Fiber Board 0.087 0.60

4-4
APPENDIX 5. List of Insulating Materials in Appendix 2 by Decreasing Thermal

Conductivity Value.

APPARENT THERMAL CONDUCTIVITY*

SI UNITS ENGLISH UNITS

W/nrK Btu*in/fti»hr*°F

MATERIAL OR PRODUCT NAME

1.21 8.4 Concrete (stone)

1.042 7.14 Borosilicate Glass

0.35 2.4 Concrete (cinder)

0.245 - 0.361 1.70 - 2.50 Silicone Rubber

0.216 1.5 Rayon

0.216 1.5 Teflon

0.173 1.2 Truck Decking

0.097 0.67 Insulation Cement

0.087 0.60 Zirconia Fiber Board

0.085 - 0.139 0.59 - 0.96 Vermiculite (concrete)

0.082 - 0.100 0.57 - 0.69 Vinyl Flooring Material

0.081 - 0.125 0.56 - 0.87 Fibair Filter Media

0.072 - 0.134 0.50 - 0.93 Perlite (concrete)

0.062 0.43 Felted Ceramic Fiber

0.061 0.42 Closed-Cell Foam Glass

0.058 0.40 Calcium Si 1 icate

0.056 0.39 Wood Fiber Board

0.056 0.39 Glass-Foam

0.055 0.38 Wood Fiber Sheathing

*Because of the nature of this report to assess the kinds of products that are actually in use, there will be an occasional use of a trade name or a manufacturer ' r. name. This in no way represents an endorsement of a particular product or manufacturer. The thermal parameter values for the various insulating mater; , were obtained from the literature or from researchers. These values were no f based on experimental research at NBS.

5-1
SI UNITS

W/m*K

ENGLISH UNITS

Btu*in/ft 2 »hr*°F

MATERIAL OR PRODUCT NAME

0.049 0.34 Glass-Fiber (low-density)

0.049 0.34 MBI (low-density)

0.049 0.34 Rock & Slag Wool (loose-fill)

0.048 - 0.059 0.33 - 0.41 Vermiculite (loose-fill)

0.047 - 0.049 0.33 - 0.34 Low-Density Blanket

0.046 - 0.065 0.32 - 0.45 Blowing Wool

0.046 0.32 P 80 Molded (high-density)

0.046 0.32 Loose-Fill Mineral Fiber

0.045 0.31 Matted Glass Fibers

0.043 0.30 Mineral Rock Board

0.040 0.28 Down

0.040 0.28 Polystyrene (expanded)

0.040 0.28 Mineral Fiber

0.040 0.28 Loose-Fill Cellulose

0.039 - 0.058 0.27 - 0.40 Perlite (loose-fill)

0.039 - 0.045 0.27 - 0.31 Cel lulose

0.039 - 0.045 0.27 - 0.31 Rock & Slag Wool (batts)

0.038 0.26 MBI (high-density)

0.038 0.26 Polystyrene Beadboard

0.036 0.25 Thinsulate 200

0.036 0.25 Rigidized Silica Fibertile

0.036 0.25 Rockwool Mineral Fiber

0.035 - 0.049 0.24 - 0.35 Glass-Fiber Appl iance Insulation

0.035 0.24 Urea- Formal dehyde Foam

5-2
APPARENT THERMAL CONDUCTIVITY

SI UNITS ENGLISH UNITS

W/m*K Btu*in/ft

2 *h «°F

MATERIAL OR PRODUCT NAME

0.035 0.24 Air Craft Insulation

(fine glass-fiber)

0.035 0.24 Open-Cell Phenolic Foam

0.033 - 0.038 0.23 - 0.26 Polystyrene (molded)

0.033 0.23 TIW

0.033 0.23 Aluminum-Silicate Refractory

Fiber Insulation Blanket

0.033 0.23 P 80 Molded (low-density)

0.033 0.23 Aercor-Black

0.033 0.23 Duct Board

0.032 - 0.036 0.22 - 0.25 Glass-Fiber (high-density)

0.032 0.22 High-Density Molded Fibrous

Glass Board

0.030 - 0.036 0.21 - 0.25 Aercor Aircraft Insulation

0.030 0.21 Glass-Fiber for Industrial

Insulation

0.029 0.20 Polystyrene (extruded)

0.027 0.19 Microspheres (Fumed Silica)

0.026 0.18 Silica Aerogel Composite

Block

0.023 - 0.025 0.16 - 0.17 Polyurethane

0.020 0.14 Foil Face Insulation

0.020 0.14 Polyisocyanurate Foam

0.016 - 0.020 0.11 - 0.14 Thermax

0.010 - 0.13 0.07 - 0.09 Phenolic Foam (closed-cell)

5-3

APPENDIX 6. Insulation Manufacturers 1 Associations

6.1. Mineral Insulation Manufacturers'

Summit, NJ 07901

(201) 277-1550

6.1.1. Member Companies

a. L. C. Cassidy & Son, Inc.

1918 So. High School Road

Indianapolis, IN 46241

b. Certain-Teed Corporation

P. 0. Box 860

Valley Forge, PA 19482

c. Guardian Industries Corp.

1000 E. North Street

Albion, MI 49224

d. Knauf Fiber Glass

240 Elizabeth Street

Shelbyville, IN 46176

Association, Inc. (MIMA)

Don Cassidy, Sr.

Chairman of the Board

(317) 241-6391

G. A. Hoffmann

Vice-President

Residential Marketing

(215) 687-5000

Richard T. Galloway

Vice-Presi dent

Sales & Marketing

(517) 629-9464

Jeffrey R. Brisley

Market Manager

Residential Manufactured Housing

(317) 398-4434

e. Manville Building Materials Corp.

P. 0. Box 5108

Denver, CO 80217

f. Owens-Corning Fiberglas Corp. 4

Fiberglas Tower

Toledo, OH 43659

g. Rock Wool Manufacturing Co.

P. 0. Box 506

Leeds, AL 35094

h. Rockwool Industries, Inc.

P. 0. Box 5170

Denver, CO 80217

i. United States Mineral Products Co.

Stanhope, NJ 07874

D. W. Korte

Vice-Presi dent

General Merchandising Manager

Fiberglass Building Insulation Div.

(303) 978-2809

B. G. Woodham, Jr.

Manger Technical Services Department

Insulation Operating Division

(419) 248-8513

E. F. Cusick, Jr.

Vice-President Sales

(205) 699-6121

S. L. Matthews

Vice-President Technical Services

& Government Affairs

(303) 773-6200

J. P. Verhalen

President

(201) 347-1200

6-1
6.1.2. Mailing List of Non-Member Companies

Bethlehem Steel Corp.

Stone & Slag Division

Bethlehem, PA 18016

Harry Campbel

1

Carney Insulation Corp. R. L. Wallentine

1009 W. 80th Street

Bloomington, MN 55420

(612) 881-3837

Fiberfine

P. 0. Box 3055

Bruce Graybeal

901 Mitchell Road

Memphis, TN 38109

d. Forty-Eight Insulations, Inc. Victor Von Schlagel

P. 0. Box 1148

Aurora, IL 60507

e. Masa

1402 Dunlavy

Houston, TX 77019

R. Bertrams

(713) 521-1451

f. Spring Hope Rockwool, Inc. Barton W. Bromley

Box 880, Spring Hope, NC 27856 (919) 478-5111

g. Sun Insulation Company Charles W. Miller

1474 Valley Industrial Park Blvd.

Casa Grande, AZ 85222

h. U. S. Pipe & Foundry Company Harold Hall

3300 First Avenue, North

Birmingham, AL 35202

i. United States Gypsum Company Bruce Wittrup

101 S. Wacker Drive

Chicago, IL 60606

6.2. Thermal Insulation Manufacturers' Association (TIMA)

7 Kirby Plaza

Mt. Kisco, NY 19549

(914) 241-2284

6.2.1. Member Companies

a. Apache Building Products Company W. H. Hill

2025 E. Linden Avenue (201) 486-6723

Linden, NJ 07036

6-2
Babcock & Wilcox

P. 0. Box 923

Augusta, GA 39093

M. A.

(404)

Pereyo

798-8000

Benoit Industries, Inc.

36-26 Binz-Engleman Road

San Antonio, TX 78219

J. Willing

(800) 531-1078

Carborundum Company

P. 0. Box 337

Niagara Falls, NY 14302

W. J.

(716)

Breitsman

278-6349

Celotex Corporation

1500 North Dale Mabry

Tampa, FL 33607

E. F. (813)

Levi n 871-4545

C-E Refractories

P. 0. Box 828

Valley Forge, PA 19482

P. J.

(215)

Longua

337-1100

CertainTeed Corporation

P. 0. Box 860

Valley Forge, PA 19482

L. J.

(215)

Law

341-7134

GAF Corporation

1361 Alps Road

Wayne, NJ 07470

W. C.

(201)

Schwi ngen

628-4130

Homasote Company

P. 0. Box 7240

West Trenton, NJ 08628

P. D.

(609)

Petri no 883-3300

International Permalite, Inc.

300 N. Haven Avenue

Ontario, Canada 91761

J. Carcich

(714) 983-9591

Knauf Fiber Glass

240 Elizabeth Street

Shelbyville, IN 46176

D. G.

(317)

Anewal

t

398-4434

Koppers Company, Inc.

700 Koppers Building

Pittsburgh, PA 15219

W. Spencer

(412) 227-2272

Manville Products Corporation

Ken-Caryl Ranch

W. R.

(303)

Browne

978-2000

Denver, CO 80217

6-3
n. NRG Barriers, Inc.

61 Emery Street

Sanford, ME 04073

u. s. (207)

Jel In

324-7745

o. Owens-Corning Fiberglas Corp.

Fiberglas Tower

Toledo, OH 43659

L. T.

(419)

Solari

248-8753

p. Pabco Insulation Division

P. 0. Box 1328

Ruston, LA 71270

K. P.

(318)

Cachill

251-2920

q. Pittsburgh-Corning Corp.

800 Presque Isle Drive

Pittsburgh, PA 15239

C. P.

(412)

Smolensk!"

327-6100

r. Rmax, Inc.

13524 Welch Road

Dallas, TX 75234

R. W.

(214)

Gri ner 387-4500

s. Rock Wool Manufacturing Company

P. 0. Box 506

Leeds, AL 35094

E. F. (205)

Cusick, Jr.

699-6121

t. Temple-Eastex, Inc.

P. 0. Box Drawer N Diboll, TX 75941

A. Tillery

(409) 829-1219

u. Thermal Systems, Inc.

2250 S. Redwood Road, Suite 2

Salt Lake City, UT 84119

H. L.

(801)

Woodcock

972-6650

v. U. S. Gypsum Company

101 South Wacker Drive

W. B. (312)

McManus

312-4000

Chicago, IL 60606

6.3. Rubber Manufacturers 1 Association

1400 K Street, NW

Washington, DC 20005

(202) 682-4818

6.4. Society of Plastic Industries

355 Lexington Avenue

New York, NY 10017

(212) 573-9400

6-4
FO«M NBS-1 14 A iREV 1184)

O.S. DEPT. OF COMM.

BIBLIOGRAPHIC DATA

SHEET (See instructions)

1. PUBLICATION OR

REPORT NO.

NBSIR 85-3146

2. Performing Organ. Report No 3. Publ i cation Date Hay 1985 4.

TITLE AND SUBTITLE

An Assessment of Needs for New Thermal Reference Materials

5. AUTHOR(S)

Brian Rennex

6.

PERFORMING ORGANIZATION (If joint or other than N BS, see instructions)

NATIONAL BUREAU OF STANDARDS

U S. DEPARTMENT OF COMMERCE

GAITHERSBURG, MD 20899

7. Contract/Grant No.

8 . Type of Report & Period Covered

9.

SPONSORING ORGANIZATION NAME AND COMPLETE ADDRESS (Street, City. State. ZIP)

10.

SUPPLEMENTARY NOTES

Document describes a computer program; SF-185, FlPS Software Summary, is attached.

11.

ABSTRACT (A 200-word or less factual summary of most significant information. If document includes a significant

bibliography or literature survey, mention it here)

Thermal insulation specimens are required by users to calibrate their heat transfer

apparatuses. This report assesses the need for additional calibration specimens to cover a wider range of test conditions and materials. It examines two major sources

of measurement error related to the use of calibration specimens. The first is due

to the lack of uniformity over a specimen area and the second is due to systematic

apparatus errors which vary with the values of specimen mean temperature and thermal

conductivity. Possible solutions to these problems are given, based on information

obtained from users in universities, industry, and government laboratories. These

include recommendations to provide calibration specimens over a wide range of values

of specimen temperature and thermal conductivity.

12.

KEY WORDS (Six to twelve entries; alphabetical order; capitalize only proper names; and separate ke,

apparent thermal conductivity; calibration; guarded hot plate; heat flow meter;

standard reference material; thermal insulation; thermal properties; therr.il

resistance

.

13. AVAILABILITY

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|

| For Official Distribution. Do Not Release to NTIS

I Order From Superintendent of Documents, U.S. Government Printing Office, Washington. D(. “ 20402.

[^X1 Order From National Technical Information Service (NTIS). Springfield. VA 22161

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