ASTM_C_1199_-_14.pdf

Designation:C119914Standard Test Method forMeasuring the Steady-State Thermal Transmittance ofFenestration Systems Using Hot Box Methods1This standard is issued under the fixed designation C1199;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 requirements and guidelinesand specifies calibration procedures required for the measure-ment of the steady-state thermal transmittance of fenestrationsystems installed vertically in the test chamber.This testmethod specifies the necessary measurements to be made usingmeasurement systems conforming to Test Method C1363 fordetermination of fenestration system thermal transmittance.NOTE1This test method allows the testing of projecting fenestrationproducts(that is,garden windows,skylights,and roof windows)installedvertically in a surround panel.Current research on skylights,roofwindows,and projecting products hopefully will provide additionalinformation that can be added to the next version of this test method sothat skylight and roof windows can be tested horizontally or at some angletypical of a sloping roof.1.2 This test method refers to the thermal transmittance,Uof a fenestration system installed vertically in the absence ofsolar radiation and air leakage effects.NOTE2The methods described in this document may also be adaptedfor use in determining the thermal transmittance of sections of buildingwall,and roof and floor assemblies containing thermal anomalies,whichare smaller than the hot box metering area.1.3 This test method describes how to determine the thermaltransmittance,USof a fenestration product(also called testspecimen)at well-defined environmental conditions.The ther-mal transmittance is also a reported test result from TestMethod C1363.If only the thermal transmittance is reportedusing this test method,the test report must also include adetailed description of the environmental conditions in thethermal chamber during the test as outlined in 10.1.14.1.4 For rating purposes,this test method also describes howto calculate a standardized thermal transmittance,UST,whichcan be used to compare test results from laboratories withvastly different thermal chamber configurations,and facilitatesthe comparison to results from computer programs that usestandard heat transfer coefficients to determine the thermaltransmittance of fenestration products.Although this testmethod specifies two methods of calculating the standardizedthermal transmittance,only the standardized thermal transmit-tance result from one method is reported for each test.Onestandardized thermal transmittance calculation procedure is theCalibration Transfer Standard(CTS)Method and another is theArea Weighting(AW)Method(see Section 9 for furtherdescriptions of these two methods).The Area Weightingmethod requires that the surface temperatures on both sides ofthe test specimen be directly measured as specified in PracticeE1423 in order to determine the surface heat transfer coeffi-cients on the fenestration product during the test.The CTSMethod does not use the measured surface temperatures on thetest specimen and instead utilizes the calculation of equivalentsurface temperatures from calibration data to determine the testspecimen surface heat transfer coefficients.The AW shall beused whenever the thermal transmittance,US,is greater than3.4 W/(m2K)0.6 Btu/(hrft2F),or when the ratio of testspecimen projected surface area to wetted(that is,total heattransfer or developed)surface area on either side of the testspecimen is less than 0.80.Otherwise the CTS Method shall beused to standardize the thermal transmittance results.1.5 Adiscussion of the terminology and underlying assump-tions for measuring the thermal transmittance are included.1.6 The values stated in SI units are to be regarded as thestandard.The values given in parentheses are provided forinformation purposes only.1.7 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:2C168 Terminology Relating to Thermal Insulation1This 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 Feb.1,2014.Published February 2014.Originallyapproved in 1991.Last previous edition approved in 2012 as C1199 12.DOI:10.1520/C1199-14.2For 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