ASTM E861-13

Designation: E861 − 13Standard Practice forEvaluating Thermal Insulation Materials for Use in SolarCollectors1This standard is issued under the fixed designation E861; 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 practice sets forth a testing methodology forevaluating the properties of thermal insulation materials to beused in solar collectors with concentration ratios of less than10. Tests are given herein to evaluate the pH, surface burningcharacteristics, moisture adsorption, water absorption, thermalresistance, linear shrinkage (or expansion), hot surfaceperformance, and accelerated aging. This practice provides atest for surface burning characteristics but does not provide amethodology for determining combustibility performance ofthermal insulation materials.1.2 The tests shall apply to blanket, rigid board, loose-fill,and foam thermal insulation materials used in solar collectors.Other thermal insulation materials shall be tested in accordancewith the provisions set forth herein and should not be excludedfrom consideration.1.3 The assumption is made that elevated temperature,moisture, and applied stresses are the primary factors contrib-uting to the degradation of thermal insulation materials used insolar collectors.1.4 Solar radiation is not considered a contributing factorsince insulating materials are not normally exposed to it.1.5 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:2C177 Test Method for Steady-State Heat Flux Measure-ments and Thermal Transmission Properties by Means ofthe Guarded-Hot-Plate ApparatusC209 Test Methods for Cellulosic Fiber Insulating BoardC356 Test Method for Linear Shrinkage of Preformed High-Temperature Thermal Insulation Subjected to SoakingHeatC411 Test Method for Hot-Surface Performance of High-Temperature Thermal InsulationC518 Test Method for Steady-State Thermal TransmissionProperties by Means of the Heat Flow Meter ApparatusC553 Specification for Mineral Fiber Blanket Thermal Insu-lation for Commercial and Industrial ApplicationsC687 Practice for Determination of Thermal Resistance ofLoose-Fill Building InsulationD2842 Test Method for Water Absorption of Rigid CellularPlasticsE84 Test Method for Surface Burning Characteristics ofBuilding MaterialsE772 Terminology of Solar Energy Conversion3. Terminology3.1 The definitions and description of terms found in thisstandard may be included in Terminology E772.4. Summary of Practice4.1 The following factors, in most cases, should be consid-ered when evaluating insulation materials for use in solarcollectors. Design considerations should dictate priorities inmaterial test evaluations:Factor ReferenceSectionpH 8.2Surface Burning Characteristics 8.3Moisture Adsorption 8.4Water Absorption 8.5Thermal Resistance 8.6Linear Shrinkage (or Expansion) 8.7Hot Surface Performance 8.8Chemical Compatibility 8.9Outgassing 8.10Durability 8.115. Significance and Use5.1 The exposure conditions in solar collectors, especiallyunder stagnation conditions, may degrade the performance of1These test methods are under the jurisdiction of ASTM Committee E44 onSolar, Geothermal and Other Alternative Energy Sources and is the direct respon-sibility of Subcommittee E44.05 on Solar Heating and Cooling Systems andMaterials.Current edition approved Nov. 1, 2013. Published December 2013. Originallyapproved in 1982. Last previous edition approved in 2007 as E861 – 94 (2007).DOI: 10.1520/E0861-13.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at service@astm.org. For Annual Book of ASTMStandards volume information, refer to the standard’s Document Summary page onthe ASTM website.Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1thermal insulation materials. This practice sets forth a meth-odology for evaluating the degree of degradation, if any, of thethermal insulation materials after exposure to simulated in-service conditions.5.2 This practice is also intended to aid in the assessment oflong-term performance by comparative testing of insulationmaterials. However, correlations between performance underlaboratory and actual in-service conditions have not beenestablished.5.3 This practice also sets forth criteria that shall be con-sidered in the selection and specification of thermal insulationmaterials. One such criterion is surface burning characteristics(Test Method E84), which is used by many code officials as areference. This practice does not represent that the numericalvalues obtained in any way reflect the anticipated performanceof the thermal insulation under actual fire conditions.6. Sampling and Test Specimens6.1 Representative specimens shall be selected at randomfrom the original sample lot for each test condition.6.2 At least three representative specimens shall be mea-sured for each property tested unless otherwise stipulated in aparticular test.6.3 The size and shape of the representative specimens shallbe as specified in the property measurement test.6.4 A separate set of test specimens shall be prepared foreach test.7. Conditioning7.1 Unless otherwise specified, maintain the test specimensin a conditioned space at 24°C (75 6 5°F) and 50 6 5%relative humidity for at least 48 h before testing.7.2 Maintain test samples in the conditioned space untilremoved to perform a particular test sequence.8. Procedure8.1 Conduct all the tests described in 8.2 – 8.11. Thesequence of testing is optional.8.2 pH:8.2.1 Measure the pH of a mixture consisting of the insula-tion material and water with a pH meter using the followingprocedure:8.2.1.1 Pulverize a sample of approximately5goftheinsulation to pass through a 4760-µm sieve.8.2.1.2 Mix the pulverized sample with 100 mL of distilledwater at 24°C (75 6 5°F) in a 500-mL glass beaker.8.2.1.3 Stir the mixture, using a glass rod, and allow to standfor1hat24°C (75 6 5°F).8.2.1.4 Measure the pH to the nearest 0.1 unit.8.2.2 Calibrate the pH meter and electrodes before eachtesting sequence using standard buffer solutions. Buffer solu-tion pH shall be within 6 2 pH units of the expected measuredpH.8.3 Surface Burning Characteristics—Determine flamespread and smoke-developed classifications of the insulationmaterial in accordance with Test Method E84.8.4 Moisture Adsorption—Determine the moisture adsorp-tion of the insulation material in accordance with SpecificationC553. Express the quantity of moisture (water) adsorbed by theinsulation material as a percentage by mass and by volume.8.5 Water Absorption— Determine the water absorption ofthe insulation material in accordance with Methods C209 orTest Method D2842 as applicable. Express the quantity ofwater absorbed by the insulation material as a percentage bymass and by volume.8.6 Thermal Resistance—Determine the thermal resistanceof the insulation material in accordance with Test MethodsC518, C177, or Practice C687, as applicable.8.7 Linear Shrinkage— Determine the linear shrinkage (orexpansion) of the insulation material in accordance with TestMethod C356, at the expected maximum in-servicetemperature, including stagnation conditions.NOTE 1—Maximum in-service temperatures, including stagnation con-ditions must be determined by testing the solar collector design underconsideration.8.8 Hot Surface Performance—Determine the hot surfaceperformance in accordance with Test Method C411. Testmaterials at the expected maximum in-service temperature,including stagnation conditions. See Note 1.8.9 Chemical Compatibility with Adjoining Material:8.9.1 Cut samples of adjoining materials to be evaluated to100 by 40 mm (3.7 by 1.5 in.) from stock materials and washthoroughly with cr grade isopropyl alcohol. After dryingovernight in a desiccator, weigh the samples to at least foursignificant figures. Then photograph the specimens at a mag-nification of 200×.8.9.1.1 Cut samples of the insulation material to be evalu-ated to 145 by 90 mm (5.7 by 3.5 in.) along with a surgicalcotton control sample that has been thoroughly washed with cpgrade isopropyl alcohol.8.9.1.2 Prepare test samples of the insulation material andcotton control using one piece of adjoining material to twopieces of insulation (or control) forming a sandwich composite.Take care to ensure intimate contact.8.9.2 Subject all the test samples to 49°C (120 6 3°F) and95 6 3 % relative humidity for 96 h. Dry the test material in adesiccator, weigh, and record the change in mass. Photographthe test materials in contact with both the insulation and thecotton control at 200× magnification of any distressed areas.Compare and contrast these photographs and record the differ-ences.8.9.2.1 Although it is recognized that this test method isappropriate for identifying chemical incompatibility in mostinsulation materials, it must be stated that other temperatureand humidity parameters will also induce distress.8.10 Outgassing (Volatile Condensibles)—Release of vola-tiles from the insulation materials, in some cases, may be asignificant factor that can effect the transmittance of a coverplate, or the properties of the absorber itself, or both. It isexpected that elevated temperatures or reactions, or both,E861 − 132between materials may cause outgassing. A generally appli-cable test is not presently available to evaluate effects ofoutgassing products. It is essential however, that this factor berecognized.8.11 Durability:8.11.1 Evaluate the durability of the test sample by measur-ing the thermal resistance of the insulation material in accor-dance with 8.6 before and after exposure to aging.8.11.2 Measure specimens at least 300 × 300 mm (12 × 12in.).8.11.3 Place the specimen in an aluminum pan as shown inFig8.11.4 Cover the pan and expose the specimens to maxi-mum in-service temperature, including stagnation conditions(see Note 1), for 30 days in an electric oven.8.11.5 Determine the change in thermal resistance in accor-dance with Test Methods C177, C518, or Practice C687,asapplicable, after exposure to the aging test.8.11.6 Examine the specimen and record any visiblechanges that may have occurred during accelerated aging.Observe and record changes, such as cracking, decomposition,delamination, dimensional variations, and warpage, as tonumber and extent of occurrences.9. Report9.1 The report shall include the following:9.1.1 Identification of the Insulation Material:9.1.1.1 Name of manufacturer,9.1.1.2 Generic nature of insulation material,9.1.1.3 Density, and9.1.1.4 Thickness.9.1.2 pH—Report measured pH from 8.2 to the nearest 0.1pH unit.9.1.3 Surface Burning Characteristics—Report test resultsas calculated by Section 9 of Test Method E84.9.1.4 Moisture Adsorption—Report percentage by mass andby volume as calculated by 15.4 of Specification C553.9.1.5 Water Absorption— Report percentage by mass and byvolume as calculated by 13.4 of Methods C209 or by Section10 of Test Method D2842.9.1.6 Thermal Resistance:9.1.6.1 Report test method used, test temperaturedifferential, density, and thickness.9.1.6.2 Report thermal transmission properties in accor-dance with 9.3 of Test Method C177, 9.2 of Test Method C518,or Section 7 of Practice C687.9.1.7 Linear Shrinkage (or Expansion):9.1.7.1 Report test temperature used in 8.7.9.1.7.2 Report linear shrinkage (or expansion) as calculatedby Section 7 of Test Method C356 and observations inaccordance with 7.2.4, 7.1.5, 7.1.6, 7.1.7, and 7.1.8 of TestMethod C356.9.1.8 Hot Surface Performance:9.1.8.1 Report test temperature used in 8.8.9.1.8.2 Report warpage as calculated by Section 7 of TestMethod C411 and observations in accordance with 7.1.8, 7.1.9,7.1.12, 7.1.13 of Test Method C411.9.1.9 Chemical Compatibility with Adjoining Materials—Report observed differences from 8.9.2 and include photo-graphs.E861 − 1339.1.10 Durability Results:9.1.10.1 Report test temperature used in 8.11.4.9.1.10.2 Report the change in thermal resistance expressedas a percentage from 8.11.5.9.1.10.3 Report recorded observations from 8.11.6.10. Keywords10.1 chemical compatibility; degradation; durability; insu-lation; solar collectors; stagnation; thermal insulationASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. 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