1、Designation: C687 18Standard Practice forDetermination of Thermal Resistance of Loose-Fill BuildingInsulation1This standard is issued under the fixed designation C687; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of las
2、t 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 practice presents a laboratory guide to determinethe thermal resistance of loose-fill building insulations at meante
3、mperatures between 20 and 55C (4 to 131F).1.2 This practice applies to a wide variety of loose-fillthermal insulation products including but not limited to fibrousglass, rock/slag wool, or cellulosic fiber materials; granulartypes including vermiculite and perlite; pelletized products;and any other
4、insulation material installed pneumatically orpoured in place. It does not apply to products that change theircharacter after installation either by chemical reaction or theapplication of binders or adhesives, nor does it consider theeffects of structures, containments, facings, or air films.1.3 Sin
5、ce this practice is designed for reproducible productcomparison, it measures the thermal resistance of an insulationmaterial which has been preconditioned to a relatively drystate. Consideration of changes of thermal performance of ahygroscopic insulation by sorption of water is beyond thescope of t
6、his practice.1.4 The sample preparation techniques outlined in thispractice do not cover the characterization of loose-fill materialsintended for enclosed applications. For those applications, aseparate sample preparation technique that simulates the in-stalled condition will be required. However, e
7、ven for thoseapplications, some other aspects of this practice are applicable.1.5 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.1.6 This standard does not purport to address all of thesafety concerns, if any, associated with
8、its use. It is theresponsibility of the user of this standard to establish appro-priate safety, health, and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.7 This international standard was developed in accor-dance with internationally recognized pri
9、nciples on standard-ization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2C167 Test Methods for Thicknes
10、s and Density of Blanket orBatt Thermal InsulationsC168 Terminology Relating to Thermal InsulationC177 Test Method for Steady-State Heat Flux Measure-ments and Thermal Transmission Properties by Means ofthe Guarded-Hot-Plate ApparatusC518 Test Method for Steady-State Thermal TransmissionProperties b
11、y Means of the Heat Flow Meter ApparatusC653 Guide for Determination of the Thermal Resistance ofLow-Density Blanket-Type Mineral Fiber InsulationC739 Specification for Cellulosic Fiber Loose-Fill ThermalInsulationC1045 Practice for Calculating Thermal Transmission Prop-erties Under Steady-State Con
12、ditionsC1114 Test Method for Steady-State Thermal TransmissionProperties by Means of the Thin-Heater ApparatusC1363 Test Method for Thermal Performance of BuildingMaterials and Envelope Assemblies by Means of a HotBox ApparatusC1373 Practice for Determination of Thermal Resistance ofAttic Insulation
13、 Systems Under Simulated Winter Condi-tions3. Terminology3.1 Unless otherwise stated, the terms and definitions foundin Terminology C168 are applicable herein.4. Significance and Use4.1 The thermal resistance, R, of an insulation is used todescribe its thermal performance.1This practice is under the
14、 jurisdiction of ASTM Committee C16 on ThermalInsulation and is the direct responsibility of Subcommittee C16.30 on ThermalMeasurement.Current edition approved Sept. 1, 2018. Published October 2018. Originallyapproved in 1971. Last previous edition approved in 2017 as C687 17. DOI:10.1520/C0687-18.2
15、For 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 C7
16、00, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the W
17、orld Trade Organization Technical Barriers to Trade (TBT) Committee.14.2 The thermal resistance of an insulation is related to thedensity and thickness of the insulation. It is desirable to obtaintest data on thermal resistances at thicknesses and densitiesrelated to the end uses of the product.4.3
18、In normal use, the thickness of these products rangefrom less than 100 mm (4 in.) to greater than 500 mm (20 in.).Installed densities depend upon the product type, the installedthickness, the installation equipment used, the installationtechniques, and the geometry of the insulated space.4.4 Loose-f
19、ill insulations provide coverage information us-ing densities selected by manufacturers to represent the productsettled densities. Generally, it is necessary to know the productthermal performance at a representative density. Some cover-age charts utilize multiple densities to show that greaterthick
20、ness installations usually result in higher installed densi-ties. The use of multiple densities can be detected from thecoverage chart by calculating the density for several differentthermal resistance levels. (The density for a given thermalresistance can be calculated from the coverage chart bydiv
21、iding the minimum mass per unit area by the minimumthickness.) If the calculated densities are significantly differentat different thermal resistances, the multiple density strategyhas been used.4.5 When applicable specifications or codes do not specifythe nominal thermal resistance level to be used
22、 for comparisonpurposes, a recommended practice is to use the Rsi(met-ric) = 3.3 m2K/W (RIP=19hft2F/Btu) label density andthickness for that measurement.4.6 If the density for test purposes is not available from thecoverage chart, a test density shall be established by use ofapplicable specification
23、s and codes or, if none apply, agreementbetween the requesting body and the testing organization.4.7 Generally, thin sections of these materials are notuniform. Thus, the test thickness must be greater than or equalto the products representative thickness if the results are to beconsistent and typic
24、al of use.NOTE 1The representative thickness is specific for each product andis determined by running a series of tests in which the density is heldconstant but the thickness is increased. The representative thickness isdefined here as that thickness above which there is no more than a 2 %change in
25、the resistivity of the product. The representative thickness is afunction of product blown density. In general, as the density decreases, therepresentative thickness increases. Fortunately, most products are de-signed to be blown over a small range of densities. This limited rangeyields a range of r
26、epresentative thicknesses between 100 to 200 mm (4 to8 in.) for most products. To simplify the process for this Practice, therepresentative thickness for the C687 tests shall be determined at themidpoint of the blown density range. Once this is accomplished, allthermal testing on this product is con
27、ducted at a thickness that is greateror equal to the representative thickness.4.7.1 For this practice, the minimum test thickness shall be100 mm (4 in.) or the representative thickness, whichever islarger. If the test is to represent an installation at a lesserthickness, the installed thickness shal
28、l be used.4.8 Because of the high cost of construction and operationof large test equipment, it is impractical to test at the higherthicknesses at which products are used. For purposes of thispractice, it is acceptable to estimate the thermal resistance atany thickness from the thermal resistivity o
29、btained from testson the product at the minimum test thickness (see 4.7.1) and atthe density expected for the proposed thickness.4.9 In principle, any of the standard methods for thedetermination of thermal resistance are suitable for loose-fillproducts. These include Test Methods C177, C518, C1114,
30、 andC1363. Of these test methods, the heat flow meter apparatus,Test Method C518, is preferred.4.10 The thermal resistance of low-density insulations de-pend upon the direction of heat flow. Unless otherwisespecified, tests shall be performed for the maximum heat flowcondition, that is, a horizontal
31、 specimen with heat flow-up.4.11 Specimens shall be prepared in a manner consistentwith the intended installation procedure. Products for pneu-matic installation shall be pneumatically applied (blown), andproducts for pour-in-place installation shall be poured intospecimen frames.4.12 Loosefill insu
32、lation installed in attic applications willhave heat flow up during the winter. At winter design condi-tions in many areas, the winter design temperature differencewill cause convective heat transfer to occur within someloose-fill insulations. The procedure outlined in Practice C687is not applicable
33、 to that measurement unless a Test MethodC1363 test apparatus is used to reproduce the correct boundaryconditions. To determine how seasonal differences can affectproduct performance, use Practice C1373. Practice C1373measures the expected winter thermal performance of loose-fillinsulation under sim
34、ulated winter design temperature condi-tions and provides specimen requirements necessary for thatdetermination.5. Apparatus5.1 Thermal test apparatus used for this practice shall meetthese requirements.5.1.1 Conformance to StandardsThe apparatus shall con-form to all requirements of the ASTM therma
35、l test methodused.5.1.2 Size and ErrorThe apparatus shall be capable oftesting specimens up to at least 150-mm (6-in.) thickness withan estimated error not greater than 1 % attributed to thickness/guard dimensions. (Parametric studies using a mathematicalmodel of the proposed apparatus will give ins
36、ight to thisevaluation. For example see Table 1 in the 1976 revision ofTest Method C518.3)NOTE 2Thermal test apparatus in use for this practice have overallplate dimensions of 457 to 1220 mm (18 to 48 in.) square with meteringareas 152 to 457 mm (6 to 18 in.) square. Other sizes are acceptable ifpro
37、per consideration of the size-thickness restrictions as outlined in thetest method are observed in their design. (See Practice C1045 foradditional discussion.)5.1.3 TemperatureAs a minimum, the apparatus shall becapable of testing at a mean temperature of 23.9C (75F) witha temperature difference of
38、20 to 28C (36 to 50F). The3See Table 1, “Maximum Spacing Between Warm and Cold Plates of HeatFlowmeter Apparatus,” of Test Method C518 76 published in 1985 Annual Bookof ASTM Standards, Vol 04.06.C687 182equipment shall be calibrated at the same temperatures as thetest conditions. Some existing test
39、 apparatus have been de-signed to provide measurements over a range of mean tem-peratures from 20 to 55C (4 to 131F) and for a wider rangeof temperature differences.5.1.4 HumidityThe absolute humidity within the test ap-paratus shall be maintained low enough to prevent condensa-tion within the speci
40、men or on the cold plate(s). A maximum9C (48F) dew point is consistent with the recommendedmaterial conditioning levels.5.1.5 Orientation and Direction of Heat FlowThe thermaltest apparatus shall be capable of testing horizontal specimenswith heat flow-up. This orientation represents the most advers
41、eheat flow condition for testing between two solid boundaries.5.1.6 Thermal Test Specimen FrameThe test frame shallbe sized to match the test apparatus and shall be made ofmaterials having low thermal conductivity (0.12 W/m K) andminimum thickness. A thin, thermally insignificant, screen ormembrane
42、is stretched across the bottom to support thematerial. Frames have fixed rigid sides or fold-down,collapsible, or compressible sides (see Fig. 1 and Fig. 2).5.2 Specimen Preparation Equipment:5.2.1 Blowing MachineA blowing apparatus is requiredwhen pneumatically applied specimens are to be tested.Ch
43、oose the combination of hopper, blower, and hose size andlength that is representative of common use for the applicationof the material to be tested. The following machine specifica-tions have been developed for use with mineral wool andcellulosic materials.5.2.1.1 Mineral Fiber Insulations:(1) Blow
44、ing MachineA commercial blowing machinewith a design capacity for delivering the subject material at arate between 4 and 15 kg (9 to 33 lb)/min.(2) Blowing HoseThe machine shall utilize 46 m (150 ft)of typical 75 to 100 mm (3 to 4 in.) diameter flexible, internallycorrugated blowing hose. At least 3
45、0 m (100 ft) of the hoseshall be elevated between 3 and 6 m (10 and 20 ft) above theoutlet of the blowing machine to simulate a typical installationconfiguration. The hose shall have no more than eight 90bends and all bends shall be greater than 1.2-m (4-ft) radius.Before each sample preparation ses
46、sion, examine the hose formaterial remaining from previous blows. Dislodge any remain-ing material by mechanically agitating the hose when themachine is running. Repeat as necessary to maintain a cleanhose for each specimen.NOTE 3In case of dispute, for mineral fiber insulations a 75 mm (3 in.)hose
47、shall be used to prepare the specimens.5.2.1.2 Cellulosic Insulations:NOTE 1Dimensions to match thermal test apparatus.FIG. 1 Rigid Test FrameC687 183(1) Blowing MachineUse commercial blowing equip-ment designed for cellulosic material, that is, hopper, blower,and 30 m (100 ft) of typical 50 to 75 m
48、m (2 to 3 in.) diameterhose.(2) Settled Density Catch ContainersContainers shall besized to match the test frames and shall be made of plywood orsimilar materials. A thin sheet of plywood attached across thebottom supports the insulation. Frames shall have fixed sides.NOTE 4In case of dispute, for c
49、ellulosic insulations a 51 mm (2 in.)hose shall be used to prepare the specimens5.2.2 Test Area Specimen CutterA means for isolating thematerial within the metering area is required for the densitydetermination. The isolated region shall have an area and shapeidentical to the metering area. Fig. 3 provides an example of adie cutter used for this purpose. The use of a compression plateto compress an area larger than the metering area, prior tometering area material removal is recommended. The compres-sion plate shall extend at least 75 mm (3 in.
