1、Designation: C 1199 00 (Reapproved 2008)Standard Test Method forMeasuring the Steady-State Thermal Transmittance ofFenestration Systems Using Hot Box Methods1This standard is issued under the fixed designation C 1199; the number immediately following the designation indicates the year oforiginal ado
2、ption 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 calibr
3、ation 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 either Test MethodsC 236, C 976,orC 1363 fo
4、r determination of fenestrationsystem thermal transmittance.NOTE 1This 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
5、 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, U,and the corresponding thermal resi
6、stance, R, of a fenestrationsystem installed vertically in the absence of solar and airleakage effects.NOTE 2The 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 anomal
7、ies, whichare smaller than the hot box metering area.1.3 This test method describes how to determine a fenestra-tion products (also called test specimen) thermal transmit-tance, US, at well-defined environmental conditions. The ther-mal transmittance, which is sometimes called the air-to-airU-factor
8、, is also a reported test result from Test Methods C 236,C 976, and C 1363. If only the thermal transmittance isreported using this test method, the test report must alsoinclude a detailed description of the environmental conditionsin the thermal chamber during the test as outlined in 10.3.1.4 For r
9、ating purposes, this test method also describes howto calculate a standardized thermal transmittance, UST, whichcan be used to compare test results from laboratories withdifferent weather side wind directions and thermal chamberconfigurations, and can also be used to directly compare tocalculated re
10、sults from current computer programs for deter-mining the thermal transmittance of fenestration products.Although this test method specifies two methods of calculatingthe standardized thermal transmittance, only the standardizedthermal transmittance result from one method is reported foreach test. O
11、ne standardized thermal transmittance calculationprocedure is the Calibration Transfer Standard (CTS) methodand another is the area weighting (AW) method (see 4.3 andSection 8 for further descriptions of these two methods). Thearea weighting method requires that the surface temperatureson both sides
12、 of the test specimen be directly measured asspecified in Practice E 1423 in order to determine the surfaceheat transfer coefficients on the fenestration product during thetest. The CTS method does not use the measured surfacetemperatures on the test specimen and instead utilizes thecalculation of e
13、quivalent surface temperatures from calibrationdata to determine the test specimen surface heat transfercoefficients. The area weighting (AW) method shall be usedwhenever the thermal transmittance, US, is greater than 3.4W/(m2K) 0.6 Btu/(hrFt2F), or when the ratio of testspecimen projected surface a
14、rea 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
15、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
16、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.1This test method is under the jurisdiction ofASTM Committee C16 on ThermalInsulation and is the direct responsibility of Subcommittee C16.30 on
17、ThermalMeasurement.Current edition approved Oct. 15, 2008. Published July 2009. Originallyapproved in 1991. Last previous edition approved in 2000 as C 1199 00.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.2. Referenced Documents2.
18、1 ASTM Standards:C 168 Terminology Relating to Thermal InsulationC 177 Test Method for Steady-State Heat Flux Measure-ments and Thermal Transmission Properties by Means ofthe Guarded-Hot-Plate ApparatusC 236 Test Method for Steady-State Thermal Performanceof Building Assemblies by Means of a Guarded
19、 Hot Box2C 518 Test Method for Steady-State Thermal TransmissionProperties by Means of the Heat Flow Meter ApparatusC 976 Test Method for Thermal Performance of BuildingAssemblies by Means of a Calibrated Hot Box2C 1045 Practice for Calculating Thermal TransmissionProperties Under Steady-State Condi
20、tionsC 1114 Test Method for Steady-State Thermal TransmissionProperties by Means of the Thin-Heater ApparatusC 1363 Test Method for Thermal Performance of BuildingMaterials and Envelope Assemblies by Means of a HotBox ApparatusE 283 Test Method for Determining Rate of Air LeakageThrough Exterior Win
21、dows, Curtain Walls, and DoorsUnder Specified Pressure Differences Across the SpecimenE 631 Terminology of Building ConstructionsE 783 Test Method for Field Measurement of Air LeakageThrough Installed Exterior Windows and DoorsE 1423 Practice for Determining Steady State ThermalTransmittance of Fene
22、stration Systems2.2 ISO Standards:ISO 8990 Thermal Insulation-Determination of Steady-State Thermal Transmission PropertiesCalibrated andGuarded Hot Box3ISO125671:2000 Thermal InsulationDetermination ofThermal Resistance of ComponentsHot Box Methodfor Windows and Doors32.3 Other Standards:NFRC 100-9
23、7 Procedure for Determining FenestrationProduct Thermal U-factors4BS874 Part 3, Section 3.1, 1987, British Standard Methodsfor Determining Thermal Insulation Properties, (Part 3,Tests for Thermal Transmittance and Conductance, Sec-tion 3.1) Guarded Hot Box Method5BS874 Part 3, Section 3.2, 1990, Bri
24、tish Standard Methodsfor Determining Thermal Insulation Properties, Part 3,Tests for Thermal Transmittance and Conductance, Sec-tion 3.2 Calibrated Hot Box Method5ASHRAE Fundamentals Handbook, 199763. Terminology3.1 DefinitionsDefinitions and terms are in accordancewith definitions in Terminologies
25、E 631 and C 168, from whichthe following have been selected and modified to apply tofenestration systems. See Fig. 1 for temperature locations.3.2 Definitions of Terms Specific to This Standard:3.2.1 calibration transfer standard, n an insulation boardthat is faced with glazing, and instrumented wit
26、h temperaturesensors between the glazing and the insulation board core,which is used to calibrate the surface resistances and thesurround panel (see Annex A1 for design guidelines forcalibration transfer standards).3.2.2 overall thermal resistance, RS, nthe temperaturedifference between the environm
27、ents on the two sides of a bodyor assembly when a unit heat flow per unit area is establishedthrough the body or assembly under steady-state conditions. Itis defined as follows:RS5 1/US(1)3.2.3 standardized thermal transmittance, UST, nthe heattransmission in unit time through unit area of a test sp
28、ecimenand standardized boundary air films, induced by unit tempera-ture difference between the environments on each side. It iscalculated using the CTS method as follows:1/USTCTS5 1/US11/hSTh1/hh!11/hSTc1/hc! (2)and using the area weighting (AW) method:1/USTAW51/US1AS/Ah!1/hSTh1/hh!1AS/Ac!1/hSTc1/hc
29、!(3)where hSThand hSTcare the standardized surface heat transfercoefficients on the room side and weather side, respectively.Their numerical values are specified in 8.2.9.1.3.2.3.1 DiscussionThe calculation of the standardizedthermal transmittance, UST, assumes that only the surface heattransfer coe
30、fficients change from the calibrated standardizedvalues for the conditions of the test. This assumption may notbe valid if the surface temperature differentials for the stan-dardized calibration conditions are different from the surfacetemperature differential that existed for the fenestration produ
31、ctduring the test procedure. Therefore, the standardized thermaltransmittance should only be considered as an approximationfor use in comparing with calculated thermal transmittancevalues with standardized surface heat transfer coefficients.2Withdrawn. The last approved version of this historical st
32、andard is referencedon www.astm.org.3Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036, http:/www.ansi.org.4Available from National Fenestration Rating Council, 1300 Spring Street, Suite120, Silver Spring, MD 20910.5Available from British Stand
33、ards Institute (BSI), 389 Chiswick High Rd.,London W4 4AL, U.K., http:/www.bsi-.6Available from American Society of Heating, Refrigerating, and Air-Conditioning Engineers, Inc. (ASHRAE), 1791 Tullie Circle, NE, Atlanta, GA30329, http:/www.ashrae.org.FIG. 1 Schematic Representation of Various Tempera
34、tures forFenestration SystemsC 1199 00 (2008)23.2.4 surface resistance, nthe temperature difference be-tween an isothermal surface and its surroundings when a unitheat flow per unit area is established between the surface andthe surroundings under steady-state conditions by the com-bined effects of
35、convection and radiation. Subscripts h and care used to differentiate between room side and weather sidesurface resistances, respectively. Surface resistances are calcu-lated as follows:rh5 1/hh(4)rc5 1/hc(5)3.2.5 surface heat transfer coeffcient, h, nthe time rate ofheat flow from a unit area of a
36、surface to its surroundings,induced by a unit temperature difference between the surfaceand the environment. (This is sometimes called surface con-ductance or film coeffcient.)3.2.5.1 DiscussionSubscripts are used to differentiate be-tween room side (1 or h) and weather side (2 or c) surfaceconditio
37、ns (see Fig. 1). It should be recognized that due toradiation effects, the room side or weather side temperature (thand tc, respectively), may differ from the respective room sideor weather side baffle temperatures (tb1and tb2, respectively).If there is a difference of more than 61C(62.0 F), either
38、onthe room side or weather side, the radiation effects shall beaccounted for to maintain accuracy in the calculated surfaceheat transfer coefficients. The areas used to calculate thesurface heat transfer coefficients (Eq 6 and 8) are differentdepending on which method of standardization is used. Whe
39、nthe CTS Method is used to standardize the thermal transmit-tance, the projected area, AS, is used to calculate the surfaceheat transfer coefficients, whereas when using the area weight-ing method, the actual “wetted or heat transfer” surface area,Ahor Ac, is used to determine the surface heat trans
40、fercoefficients.The room side and weather side surface heat transfer coefficients arecalculated as follows:when:th5 tb161C!, (6)hh5 QS/ASorh!th t1!#when:thfi tb161 C!, (7)hh5 qr11 qc1!/th t1!when:tc5 tb261C!,hc5 QS/ASorc! t2 tc!#when:tcfi tb26 1C!, (8)hc5 qr21 qc2!/t2 tc! (9)3.2.5.2 DiscussionWhen t
41、esting inhomogeneous testspecimens, the test specimen surface temperatures and surfaceheat transfer coefficients will not be exactly the same as thoseobtained using the calibration transfer standard. As a conse-quence, the surface heat transfer coefficients obtained using thecalibration transfer sta
42、ndard cannot be unambiguously definedand hence a test specimen conductance cannot be defined andmeasured. For inhomogeneous test specimens, only the thermaltransmittance, US, can be defined and measured. It is thereforeessential to calibrate with surface heat transfer coefficients onthe Calibration
43、Transfer Standard (CTS) which are as close aspossible to the conventionally accepted values for buildingdesign. Likewise, it would be desirable to have a surroundpanel that closely duplicates the actual wall where the fenes-tration system would be installed. However, due to the widevariety of fenest
44、ration opening designs and constructions, thisis not feasible. Furthermore, for high resistance fenestrationsystems installed in fenestration opening designs and construc-tions that are thermal bridges, the large relative amount of heattransfer through the thermal bridge will cause the relativelysma
45、ll amount of heat transfer through the fenestration systemto have a larger than desirable error. As a result of the pointsstated above, the calculation of a specimen thermal conduc-tance or resistance (surface to surface) from a measuredthermal transmittance and the calculated surface heat transferc
46、oefficients is not part of the basic measurement procedure.However, by using the CTS method or the area weighting(AW) method described in Section 8 it is possible to obtain astandardized thermal transmittance, UST, which is a ratheruseful tool for the evaluation and comparison of experimentalresults
47、 for fenestration systems with computer calculations ofthe thermal transmittance.3.2.6 surround panel (sometimes called the mask, maskwall, or homogeneous wall), na homogeneous panel with anopening where the test specimen is installed (see 5.1.2 for adescription of a surround panel.)3.2.7 test speci
48、men, nthe fenestration system or productbeing tested.3.2.8 test specimen thermal transmittance, US(sometimescalled the overall coefficient of heat transfer or air-to-airU-factor), n the heat transfer in unit time through unit area ofa test specimen and its boundary air films, induced by unittemperat
49、ure difference between the environments on each side.It is determined as follows:US5 QS/ASth tc!# (10)3.3 SymbolsThe symbols, terms, and units used in thistest method are as follows:Ah= total heat transfer (or developed) surface areaof test specimen on room side, m2,Ac= total heat transfer (or developed) surface areaof test specimen on weather side, m2,Ab1= area of room side baffle and all other surfacesin view of the test specimen, m2,Ab2= area of weather side baffle and all othersurfaces in view of th
