ASTM_C_1667_-_15.pdf

Designation:C166715Standard Test Method forUsing Heat Flow Meter Apparatus to Measure the Center-of-Panel Thermal Transmission Properties of VacuumInsulation Panels1This standard is issued under the fixed designation C1667;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This test method covers the measurement of steady-statethermal transmission through the center of a flat rectangularvacuum insulation panel using a heat flow meter apparatus.1.2 Total heat transfer through the non-homogenous geom-etry of a vacuum insulation panel requires the determination ofseveral factors,as discussed in Specification C1484.One ofthose factors is the center-of-panel thermal resistivity.Thecenter-of-panel thermal resistivity is an approximation of thethermal resistivity of the core evacuated region.1.3 This test method is based upon the technology of TestMethod C518 but includes modifications for vacuum insulationpanel applications as outlined in this test method.21.4 This test method shall be used in conjunction withPractice C1045 and Practice C1058.1.5 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.6 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:3C168 Terminology Relating to Thermal InsulationC518 Test Method for Steady-State Thermal TransmissionProperties by Means of the Heat Flow Meter ApparatusC740 Practice for Evacuated Reflective Insulation In Cryo-genic ServiceC1045 Practice for Calculating Thermal Transmission Prop-erties Under Steady-State ConditionsC1058 Practice for Selecting Temperatures for Evaluatingand Reporting Thermal Properties of Thermal InsulationC1484 Specification for Vacuum Insulation PanelsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test MethodE177 Practice for Use of the Terms Precision and Bias inASTM Test Methods3.Terminology3.1 DefinitionsTerminology C168 applies to terms used inthis specification.3.2 Definitions of Terms Specific to This Standard:3.2.1 center-of-panelthe location at the center of thelargest planar surface of the panel,equidistant from each pairof opposite edges of that surface.3.2.2 center-of-panel apparent thermal resistivitythe ther-mal performance of vacuum insulation panels includes an edgeeffect due to heat flow through the barrier material and thisshunting of heat around the evacuated volume of the panelbecomes more prevalent with greater barrier thermalconductivity,as shown in Fig.1.For panels larger than aminimum size(as described in Annex A1),the center-of-panelapparent thermal resistivity is a close approximation of theintrinsic core thermal resistivity of the vacuum insulationpanel.The effective thermal performance of a panel will varywith the size and shape of the panel.3.2.2.1 DiscussionThermal resistivity,the reciprocal ofapparent thermal conductivity,is used when discussing thecenter-of-panel thermal behavior.3.2.3 corethe material placed within the evacuated vol-ume of a vacuum insulation panel.This material may performany or all of the following functions:prevent panel collapsedue to atmospheric pressure,reduce radiation heat transfer,andreduce gas-phase conduction.The apparent thermal conductiv-ity of the core,or core,is defined as the apparent thermal1This test method is under the jurisdiction ofASTM Committee C16 on ThermalInsulation and is the direct responsibility of Subcommittee C16.30 on ThermalMeasurement.Current edition approved Oct.1,2015.Published October 2015.Originallyapproved in 2007.Last previous edition approved in 2009 as C166709.DOI:10.1520/C1667-15.2All references to particular sections of Test Method C518 within this documentrefer to the 2010 edition of Test Method C518.3For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 conductivity of the core material under the same vacuum thatwould occur within a panel,but without the barrier material.This is the apparent thermal conductivity that would bemeasured in a vacuum chamber without the barrier material.3.2.4 effective panel thermal resistance(effective panelR-value)this value reflects the total panel resistance to heatflow,considering heat flow through the evacuated region and