ASTM C1667-07
(Test Method)Standard Test Method for Using Heat Flow Meter Apparatus to Measure the Center-of-Panel Thermal Resistivity of Vacuum Panels
Standard Test Method for Using Heat Flow Meter Apparatus to Measure the Center-of-Panel Thermal Resistivity of Vacuum Panels
SIGNIFICANCE AND USE
Heat flow meter apparatus are being used to measure the center-of-panel portion of a vacuum insulation panel, which typically has a very high value of thermal resistivity [that is, equal to or greater than 90 m-K/W (12.5 h-ft2-°F/Btu-in.)]. As described in Specification C 1484, the center-of-panel thermal resistivity is used, along with the panel geometry and barrier material thermal conductivity, to determine the effective thermal resistance of the evacuated panel.
Using a heat flow meter apparatus to measure the thermal resistivity of non-homogenous and high thermal resistance specimens is a non-standard application of the equipment, and shall only be performed by qualified personnel with understanding of heat transfer and error propagation. Familiarity with the configuration of both the apparatus and the vacuum panel is necessary.
The center-of-panel thermal transmission properties of evacuated panels vary due to the composition of the materials of construction, mean temperature and temperature difference, and the prior history. The selection of representative values for the thermal transmission properties of an evacuated panel for a particular application must be based on a consideration of these factors and will not apply necessarily without modification to all service conditions.
SCOPE
1.1 This test method covers the measurement of steady-state thermal transmission through the center of a flat rectangular vacuum insulation panel using a heat flow meter apparatus.
1.2 Total heat transfer through the non-homogenous geometry of a vacuum insulation panel requires the determination of several factors, as discussed in Specification C 1484. One of those factors is the center-of-panel thermal resistivity. The center-of-panel thermal resistivity is an approximation of the thermal resistivity of the core evacuated region.
1.3 This test method is based upon the technology of Test Method C 518 but includes modifications for vacuum panel applications as outlined in this test method.
1.4 This test method shall be used in conjunction with Practice C 1045 and Practice C 1058.
1.5 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only. Either SI or inch-pound units are acceptable in the report, unless otherwise specified.
This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
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Designation:C1667–07
Standard Test Method for
Using Heat Flow Meter Apparatus to Measure the Center-of-
1
Panel Thermal Resistivity of Vacuum Panels
This standard is issued under the fixed designation C 1667; 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 (e) indicates an editorial change since the last revision or reapproval.
1. Scope C 1045 Practice for Calculating Thermal Transmission
Properties Under Steady-State Conditions
1.1 Thistestmethodcoversthemeasurementofsteady-state
C 1058 Practice for Selecting Temperatures for Evaluating
thermal transmission through the center of a flat rectangular
and Reporting Thermal Properties of Thermal Insulation
vacuum insulation panel using a heat flow meter apparatus.
C 1484 Specification for Vacuum Insulation Panels
1.2 Total heat transfer through the non-homogenous geom-
etry of a vacuum insulation panel requires the determination of
3. Terminology
several factors, as discussed in Specification C 1484. One of
3.1 Definitions—Terminology C 168 applies to terms used
those factors is the center-of-panel thermal resistivity. The
in this specification.
center-of-panel thermal resistivity is an approximation of the
3.2 Definitions of Terms Specific to This Standard:
thermal resistivity of the core evacuated region.
3.2.1 center-of-panel—the location at the center of the
1.3 This test method is based upon the technology of Test
largest planar surface of the panel, equidistant from each pair
Method C 518 but includes modifications for vacuum panel
2 of opposite edges of that surface.
applications as outlined in this test method.
3.2.2 center-of-panel apparent thermal resistivity—the ther-
1.4 This test method shall be used in conjunction with
mal performance of vacuum panels includes an edge effect due
Practice C 1045 and Practice C 1058.
to heat flow through the barrier material and this shunting of
1.5 The values stated in SI units are to be regarded as the
heat around the evacuated volume of the panel becomes more
standard. The values given in parentheses are for information
prevalentwithgreaterbarrierthermalconductivity,asshownin
only. Either SI or inch-pound units are acceptable in the report,
Fig. 1. For panels larger than a minimum size (as described in
unless otherwise specified.
AnnexA1), the center-of-panel apparent thermal resistivity is a
1.6 This standard does not purport to address all of the
close approximation of the intrinsic core thermal resistivity of
safety concerns, if any, associated with its use. It is the
the vacuum insulation panel. The effective thermal perfor-
responsibility of the user of this standard to establish appro-
manceofapanelwillvarywiththesizeandshapeofthepanel.
priate safety and health practices and determine the applica-
3.2.2.1 Discussion—Thermal resistivity, the reciprocal of
bility of regulatory limitations prior to use.
apparent thermal conductivity, is used when discussing the
2. Referenced Documents center-of-panel thermal behavior.
3
3.2.3 core—the material placed within the evacuated vol-
2.1 ASTM Standards:
ume of a vacuum insulation panel. This material may perform
C 168 Terminology Relating to Thermal Insulation
any or all of the following functions: prevent panel collapse
C 518 Test Method for Steady-State Thermal Transmission
due to atmospheric pressure, reduce radiation heat transfer, and
Properties by Means of the Heat Flow Meter Apparatus
reduce gas-phase conduction. The apparent thermal conductiv-
C 740 Practice for Evacuated Reflective Insulation In Cryo-
ity of the core, or l , is defined as the apparent thermal
core
genic Service
conductivity of the core material under the same vacuum that
would occur within a panel, but without the barrier material.
This is the apparent thermal conductivity that would be
1
ThistestmethodisunderthejurisdictionofASTMCommitteeC16onThermal measured in a vacuum chamber without the barrier material.
Insulation and is the direct responsibility of Subcommittee C16.30 on Thermal
3.2.4 effective panel thermal resistance (effective panel
Measurement.
R-value)—this value reflects the total panel resistance to heat
Current edition approved Sept. 1, 2007. Published September 2007.
2
flow, considering heat flow through the evacuated region and
AllreferencestoparticularsectionsofTestMethodC 518withinthisdocument
refer to the 2004 edition of Test Method C 518.
through the barrier material. Depending on the thermal con-
3
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
ductivity of the barrier material and the size of the panel, the
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
effective thermal resistance may be
...
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