ASTM C1045-19
(Practice)Standard Practice for Calculating Thermal Transmission Properties Under Steady-State Conditions
Standard Practice for Calculating Thermal Transmission Properties Under Steady-State Conditions
SIGNIFICANCE AND USE
4.1 ASTM thermal test method descriptions are complex because of added apparatus details necessary to ensure accurate results. As a result, many users find it difficult to locate the data reduction details necessary to reduce the data obtained from these tests. This practice is designed to be referenced in the thermal test methods, thus allowing those test methods to concentrate on experimental details rather than data reduction.
4.2 This practice is intended to provide the user with a uniform procedure for calculating the thermal transmission properties of a material or system from standard test methods used to determine heat flux and surface temperatures. This practice is intended to eliminate the need for similar calculation sections in the ASTM Test Methods (C177, C335, C518, C1033, C1114, C1199, and C1363) by permitting use of these standard calculation forms by reference.
4.3 This practice provides the method for developing the thermal conductivity as a function of temperature for a specimen from data taken at small or large temperature differences. This relationship can be used to characterize material for comparison to material specifications and for use in calculations programs such as Practice C680.
4.4 Two general solutions to the problem of establishing thermal transmission properties for application to end-use conditions are outlined in Practice C1058. (Practice C1058 should be reviewed prior to use of this practice.) One is to measure each product at each end-use condition. This solution is rather straightforward, but burdensome, and needs no other elaboration. The second is to measure each product over the entire temperature range of application conditions and to use these data to establish the thermal transmission property dependencies at the various end-use conditions. One advantage of the second approach is that once these dependencies have been established, they serve as the basis for estimating the performance for a given product at othe...
SCOPE
1.1 This practice provides the user with a uniform procedure for calculating the thermal transmission properties of a material or system from data generated by steady state, one dimensional test methods used to determine heat flux and surface temperatures. This practice is intended to eliminate the need for similar calculation sections in Test Methods C177, C335, C518, C1033, C1114 and C1363 and Practices C1043 and C1044 by permitting use of these standard calculation forms by reference.
1.2 The thermal transmission properties described include: thermal conductance, thermal resistance, apparent thermal conductivity, apparent thermal resistivity, surface conductance, surface resistance, and overall thermal resistance or transmittance.
1.3 This practice provides the method for developing the apparent thermal conductivity as a function of temperature relationship for a specimen from data generated by standard test methods at small or large temperature differences. This relationship can be used to characterize material for comparison to material specifications and for use in calculation programs such as Practice C680.
1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.5 This practice includes a discussion of the definitions and underlying assumptions for the calculation of thermal transmission properties. Tests to detect deviations from these assumptions are described. This practice also considers the complicating effects of uncertainties due to the measurement processes and material variability. See Section 7.
1.6 This practice is not intended to cover all possible aspects of thermal properties data base development. For new materials, the user should investigate the variations in thermal properties seen in similar materials. The information contained in Section 7, the Appendix and the technical papers listed in the References secti...
General Information
Relations
Buy Standard
Standards Content (Sample)
This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: C1045 − 19
Standard Practice for
Calculating Thermal Transmission Properties Under Steady-
1
State Conditions
This standard is issued under the fixed designation C1045; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope propertiesseeninsimilarmaterials.Theinformationcontained
inSection7,theAppendixandthetechnicalpaperslistedinthe
1.1 Thispracticeprovidestheuserwithauniformprocedure
Referencessectionofthispracticemaybehelpfulindetermin-
forcalculatingthethermaltransmissionpropertiesofamaterial
ing whether the material under study has thermal properties
orsystemfromdatageneratedbysteadystate,onedimensional
that can be described by equations using this practice. Some
test methods used to determine heat flux and surface tempera-
examples where this method has limited application include:
tures.Thispracticeisintendedtoeliminatetheneedforsimilar
(1) the onset of convection in insulation as described in
calculation sections in Test Methods C177, C335, C518,
Reference (1);(2) while a phase change is taking place in one
C1033, C1114 and C1363 and Practices C1043 and C1044 by
of the insulation components causing an unsteady-state condi-
permitting use of these standard calculation forms by refer-
tion; and (3) the influence of heat flow direction and tempera-
ence.
ture difference changes for reflective insulations.
1.2 The thermal transmission properties described include:
1.7 This international standard was developed in accor-
thermal conductance, thermal resistance, apparent thermal
dance with internationally recognized principles on standard-
conductivity,apparentthermalresistivity,surfaceconductance,
ization established in the Decision on Principles for the
surface resistance, and overall thermal resistance or transmit-
Development of International Standards, Guides and Recom-
tance.
mendations issued by the World Trade Organization Technical
1.3 This practice provides the method for developing the
Barriers to Trade (TBT) Committee.
apparent thermal conductivity as a function of temperature
relationship for a specimen from data generated by standard 2. Referenced Documents
2
test methods at small or large temperature differences. This
2.1 ASTM Standards:
relationship can be used to characterize material for compari-
C168Terminology Relating to Thermal Insulation
son to material specifications and for use in calculation
C177Test Method for Steady-State Heat Flux Measure-
programs such as Practice C680.
ments and Thermal Transmission Properties by Means of
1.4 The values stated in SI units are to be regarded as the Guarded-Hot-Plate Apparatus
standard. No other units of measurement are included in this C335TestMethodforSteady-StateHeatTransferProperties
standard. of Pipe Insulation
C518Test Method for Steady-State Thermal Transmission
1.5 Thispracticeincludesadiscussionofthedefinitionsand
Properties by Means of the Heat Flow Meter Apparatus
underlying assumptions for the calculation of thermal trans-
C680Practice for Estimate of the Heat Gain or Loss and the
mission properties. Tests to detect deviations from these
Surface Temperatures of Insulated Flat, Cylindrical, and
assumptions are described. This practice also considers the
Spherical Systems by Use of Computer Programs
complicating effects of uncertainties due to the measurement
C1033Test Method for Steady-State Heat Transfer Proper-
processes and material variability. See Section 7.
ties of Pipe Insulation Installed Vertically (Withdrawn
3
1.6 Thispracticeisnotintendedtocoverallpossibleaspects
2003)
of thermal properties data base development. For new
C1043Practice for Guarded-Hot-Plate Design Using Circu-
materials, the user should investigate the variations in thermal
lar Line-Heat Sources
1 2
This practice is under the jurisdiction of ASTM Committee C16 on Thermal For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Insulation and is the direct responsibility of Subcommittee C16.30 on Thermal contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Measurement. Standards volume information, refer to the standard’s Document Summary page on
Current edition approved April 1, 2019. Published May 2019. Originally the ASTM website.
3
approved in 1985. Last previous edition approved in 2013 as C1045–07 (2013). The last approved version of this historical standard is referenced on
DOI: 10.1520/C1045-19. www.astm.org.
Copyright © ASTM International, 100
...
This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: C1045 − 07 (Reapproved 2013) C1045 − 19
Standard Practice for
Calculating Thermal Transmission Properties Under Steady-
1
State Conditions
This standard is issued under the fixed designation C1045; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope
1.1 This practice provides the user with a uniform procedure for calculating the thermal transmission properties of a material
or system from data generated by steady state, one dimensional test methods used to determine heat flux and surface temperatures.
This practice is intended to eliminate the need for similar calculation sections in Test Methods C177, C335, C518, C1033, C1114
and C1363 and Practices C1043 and C1044 by permitting use of these standard calculation forms by reference.
1.2 The thermal transmission properties described include: thermal conductance, thermal resistance, apparent thermal
conductivity, apparent thermal resistivity, surface conductance, surface resistance, and overall thermal resistance or transmittance.
1.3 This practice provides the method for developing the apparent thermal conductivity as a function of temperature relationship
for a specimen from data generated by standard test methods at small or large temperature differences. This relationship can be
used to characterize material for comparison to material specifications and for use in calculation programs such as Practice C680.
1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.5 This practice includes a discussion of the definitions and underlying assumptions for the calculation of thermal transmission
properties. Tests to detect deviations from these assumptions are described. This practice also considers the complicating effects
of uncertainties due to the measurement processes and material variability. See Section 7.
1.6 This practice is not intended to cover all possible aspects of thermal properties data base development. For new materials,
the user should investigate the variations in thermal properties seen in similar materials. The information contained in Section 7,
the Appendix and the technical papers listed in the References section of this practice may be helpful in determining whether the
material under study has thermal properties that can be described by equations using this practice. Some examples where this
method has limited application include: (1) the onset of convection in insulation as described in Reference (1); (2) while a phase
change of is taking place in one of the insulation system components such as a blowing gas in foam; components causing an
unsteady-state condition; and (3) the influence of heat flow direction and temperature difference changes for reflective insulations.
1.7 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Referenced Documents
2
2.1 ASTM Standards:
C168 Terminology Relating to Thermal Insulation
C177 Test Method for Steady-State Heat Flux Measurements and Thermal Transmission Properties by Means of the
Guarded-Hot-Plate Apparatus
C335 Test Method for Steady-State Heat Transfer Properties of Pipe Insulation
C518 Test Method for Steady-State Thermal Transmission Properties by Means of the Heat Flow Meter Apparatus
C680 Practice for Estimate of the Heat Gain or Loss and the Surface Temperatures of Insulated Flat, Cylindrical, and Spherical
Systems by Use of Computer Programs
3
C1033 Test Method for Steady-State Heat Transfer Properties of Pipe Insulation Installed Vertically (Withdrawn 2003)
1
This practice is under the jurisdiction of ASTM Committee C16 on Thermal Insulation and is the direct responsibility of Subcommittee C16.30 on Thermal Measurement.
Current edition approved Sept. 1, 2013April 1, 2019. Published January 2014May 2019. Originally approved in 1985. Last previous edition approved in 20072013 as
C1045 – 07.C1045 – 07 (2013). DOI: 10.1520/C1045-07R13.10.1520/C1045-19.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at s
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.