1、Designation: C687 12Standard 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 fibrous glass, rock/slagwool, or cellulosic fiber materials; granular types includingvermiculite and perlite; pelletized products; and any otherinsulation material
4、 installed pneumatically or poured in place.It does not apply to products that change their character afterinstallation either by chemical reaction or the application ofbinders or adhesives, nor does it consider the effects ofstructures, containments, facings, or air films.1.3 Since this practice is
5、 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 this practice.1.4 Th
6、e 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, even for thoseapplic
7、ations, 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 its use. It is ther
8、esponsibility 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:2C167 Test Methods for Thickness and Density of Blanket orBatt Thermal InsulationsC168 Te
9、rminology 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 by Means of the Heat Flow Meter ApparatusC653 Guide for Det
10、ermination 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 ConditionsC1114 Test Method for Steady-State Thermal Transmis
11、sionProperties 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 Systems Under Simulated Winter Condi-tions3. Terminology3
12、.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.4.2 The thermal resistance of an insulation is related to thedensity and thickness of
13、 the insulation. It is desirable to obtaintest data on thermal resistances at thicknesses and densitiesrelated to the end uses of the product.1This practice is under the jurisdiction of ASTM Committee C16 on ThermalInsulation and is the direct responsibility of Subcommittee C16.30 on ThermalMeasurem
14、ent.Current edition approved Sept. 1, 2012. Published October 2012. Originallyapproved in 1971. Last previous edition approved in 2007 as C687 07. DOI:10.1520/C0687-12.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual
15、 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 States14.3 In normal use, the thickness of these products rangefrom less than 100 mm (
16、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-fill insulations provide coverage information us-ing densities selected by m
17、anufacturers 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 greaterthickness installations usually result in higher installed densi-ties. The use o
18、f 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 bydividing the minimum mass per unit area by the minimumthickness.) If the calcu
19、lated 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 for comparisonpurposes, a recommended practice is to use the Rsi(met-ric)
20、= 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 specifications and codes or, if none apply, agreementbetween the requesting body and the
21、 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 typical of use.NOTE 1The representative thickness is specific for each product a
22、ndis 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 the resistivity of the product. The representative thickness is afunction o
23、f 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 representative thicknesses between 100 to 200 mm (4 to8 in.) for most produc
24、ts. 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 conducted at a thickness that is greateror equal to the representative thickne
25、ss.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 shall be used.4.8 Because of the high cost of construction and operationof larg
26、e 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 obtained from testson the product at the minimum test thickness (see 4.7.1)
27、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, andC1363. Of these test methods, the heat flow meter apparatus,Test Method
28、 C518, is preferred because of its lower cost andshorter testing time.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 specimen with heat flow-
29、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 insulation installed in attic
30、 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 C687 is notapplicable to that measurement unless a C136
31、3 test apparatusis used to reproduce the correct boundary conditions. Todetermine how seasonal differences can affect productperformance, use Practice C1373. Practice C1373 measures theexpected winter thermal performance of loose-fill insulationunder simulated winter design temperature conditions an
32、dprovides specimen requirements necessary for that determina-tion.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 thermal test methodused.5.1.2 Size and ErrorThe appa
33、ratus 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 insight to thisevaluation. For example see Table
34、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 ifproper consideration of the size-thickness restri
35、ctions 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 20 to 28C (36 to 50F). Theequipment shall be c
36、alibrated at the same temperatures as thetest conditions. Some existing test 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.3See Table 1, “Maximum Spacing Between Warm and Cold Plates
37、 of HeatFlowmeter Apparatus,” of Test Method C518 76 published in 1985 Annual Bookof ASTM Standards, Vol 04.06.C687 1225.1.4 HumidityThe absolute humidity within the test ap-paratus shall be maintained low enough to prevent condensa-tion within the specimen or on the cold plate(s). A maximum9C (48F)
38、 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 adverseheat flow condition for testing between two s
39、olid 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 is stretched across the bottom to support them
40、aterial. 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.Choose the combination of hopper, blower, and ho
41、se 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) Blowing MachineA commercial blowing machinewith a
42、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 30 m (100 ft) of the hoseshall be elevated betw
43、een 3 and 6 m (10 and 20 ft) above theblowing machine to simulate a typical installation configura-tion. The hose shall have no more than eight 90 bends and allbends shall be greater than 1.2-m (4-ft) radius. Before eachsample preparation session, examine the hose for materialremaining from previous
44、 blows. Dislodge any remaining ma-terial by mechanically agitating the hose when the machine isrunning. Repeat as necessary to maintain a clean hose for eachspecimen.NOTE 3In case of dispute, for mineral fiber insulations a 75 mm (3 in.)hose shall be used to prepare the specimens.5.2.1.2 Cellulosic
45、Insulations:(1) Blowing MachineUse commercial blowing equipmentdesigned for cellulosic material, that is, hopper, blower, and 30m (100 ft) of typical 50 to 75 mm (2 to 3 in.) diameter hose.(2) Settled Density Catch ContainersContainers shall besized to match the test frames and shall be made of plyw
46、ood orNOTE 1Dimensions to match thermal test apparatus.FIG. 1 Rigid Test FrameC687 123similar materials. A thin sheet of plywood attached across thebottom supports the insulation. Frames shall have fixed sides.NOTE 4In case of dispute, for cellulosic insulations a 51 mm (2 in.)hose shall be used to
47、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. Th
48、e 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.) beyond themetering area boundary.5.2.3 Weighing DevicesA device is required to weigh thetest area material
49、after the thermal test is complete. This deviceshall determine the test area weight to within 0.5 %. A seconddevice is required during sample preparation and conditioningto determine the sample plus frame weight. This device shalldetermine the combined weight to within 0.5 %.5.2.4 Conditioning RoomAn enclosure held at near con-stant temperature and humidity is required to stabilize thematerials or products prior to testing. The conditions aregenerally given in product specifications or in other appropriatedocuments. In the absence of specifi
