1、Designation: C 687 07Standard Practice forDetermination of Thermal Resistance of Loose-Fill BuildingInsulation1This standard is issued under the fixed designation C 687; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of l
2、ast revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) 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 mea
3、ntemperatures 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 mater
4、ial 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
5、 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 this practice.1.4
6、 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, even for thoseapp
7、lications, 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 t
8、heresponsibility 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:2C 167 Test Methods for Thickness and Density of Blanketor Batt Thermal InsulationsC 1
9、68 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 518 Test Method for Steady-State Thermal TransmissionProperties by Means of the Heat Flow Meter ApparatusC 653 Guide
10、 for Determination of the Thermal Resistanceof Low-Density Blanket-Type Mineral Fiber InsulationC 739 Specification for Cellulosic Fiber Loose-Fill ThermalInsulationC 1045 Practice for Calculating Thermal TransmissionProperties Under Steady-State ConditionsC 1114 Test Method for Steady-State Thermal
11、 TransmissionProperties by Means of the Thin-Heater ApparatusC 1363 Test Method for Thermal Performance of BuildingMaterials and Envelope Assemblies by Means of a HotBox ApparatusC 1373 Practice for Determination of Thermal Resistanceof Attic Insulation Systems Under Simulated Winter Con-ditions3. T
12、erminology3.1 Unless otherwise stated, the terms and definitions foundin Terminology C 168 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
13、thickness of the insulation. It is desirable to obtain1This practice is under the jurisdiction of ASTM Committee C16 on ThermalInsulation and is the direct responsibility of Subcommittee C16.30 on ThermalMeasurement.Current edition approved Nov. 15, 2007. Published January 2008. Originallyapproved i
14、n 1971. Last previous edition approved in 2005 as C 687 05.2For 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 the standards Document Summary page onthe ASTM website.1C
15、opyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.test data on thermal resistances at thicknesses and densitiesrelated to the end uses of the product.4.3 In normal use, the thickness of these products rangefrom less than 100 mm (4 in.) t
16、o 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 manufactu
17、rers 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 of multip
18、le 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 calculated de
19、nsities 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) = 3.3 m2
20、K/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 testing
21、 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 andis det
22、ermined 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 of produc
23、t 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 products. To s
24、implify the process for this Practice, therepresentative thickness for the C 687 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 thickness.4.7.
25、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 large test
26、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) and att
27、he 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 C 177, C 518, C 1114,and C 1363. Of these test methods, the heat flow meterapparatus, Test Method C
28、518, is preferred because of its lowercost and shorter testing time.4.10 The thermal resistance of low-density insulations de-pend upon the direction of heat flow. Unless otherwise speci-fied, 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 C 687 is notapplicable to that measurement unless a C 1
31、363 test apparatusis used to reproduce the correct boundary conditions. Todetermine how seasonal differences can affect product perfor-mance, use Practice C 1373. Practice C 1373 measures theexpected winter thermal performance of loose-fill insulationunder simulated winter design temperature conditi
32、ons andprovides 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 ErrorTh
33、e 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 insight to thisevaluation. For example see
34、Table 1 in the 1976 revision ofTest Method C 518.3)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
35、 restrictions as outlined in thetest method are observed in their design. (See Practice C 1045 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 sh
36、all be calibrated at the same temperatures as the3See Table 1, “Maximum Spacing Between Warm and Cold Plates of HeatFlowmeter Apparatus,” of Test Method C 518 76 published in 1985 Annual Bookof ASTM Standards, Vol 04.06.C687072test conditions. Some existing test apparatus have been de-signed to prov
37、ide 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 specimen or on the cold plate(s). A maximum
38、9C (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 adverseheat flow condition for testing betwe
39、en 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 is stretched across the bottom to supp
40、ort thematerial. Frames have fixed rigid sides or fold-down, collaps-ible, 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, blow
41、er, 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) Blowing MachineA commercial blowing mach
42、inewith 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 30 m (100 ft) of the hoseshall be ele
43、vated between 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 fro
44、m previous 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 (3in.) hose shall be used to prepare the specimens.5.2.1.2 C
45、ellulosic Insulations:NOTE 1Dimensions to match thermal test apparatus.FIG. 1 Rigid Test FrameC687073(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 Ca
46、tch 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 cellulosic insulations a 51 mm (2 in.)hose shall be
47、 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 pu
48、rpose. 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.) beyond themetering area boundary.5.2.3 Weighing DevicesA device is required to weigh thetest area
49、material 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 s
