ASTM C687 - 24 松散填充建筑隔热材料热阻测定的标准规范

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那山那人那狗 2025-06-25 22 521.84KB 10 页 18星币
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Designation: C687 −24
Standard Practice for
Determination of Thermal Resistance of Loose-Fill Building
Insulation
1
This standard is issued under the fixed designation C687; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope
1.1 This practice presents a laboratory guide to determine
the thermal resistance of loose-fill building insulations at mean
temperatures between −20 and 55°C (−4 to 131°F).
1.2 This practice applies to a wide variety of loose-fill
thermal insulation products including but not limited to fibrous
glass, rock/slag wool, or cellulosic fiber materials; granular
types including vermiculite and perlite; pelletized products;
and any other insulation material installed pneumatically or
poured in place. It does not apply to products that change their
character after installation either by chemical reaction or the
application of binders or adhesives, nor does it consider the
effects of structures, containments, facings, or air films.
1.3 Since this practice is designed for reproducible product
comparison, it measures the thermal resistance of an insulation
material which has been preconditioned to a relatively dry
state. Consideration of changes of thermal performance of a
hygroscopic insulation by sorption of water is beyond the
scope of this practice.
1.4 The sample preparation techniques outlined in this
practice do not cover the characterization of loose-fill materials
intended for enclosed applications. For those applications, a
separate sample preparation technique that simulates the in-
stalled condition will be required. However, even for those
applications, some other aspects of this practice are applicable.
1.5 The values stated in SI units are to be regarded as the
standard. The values given in parentheses are for information
only.
1.6 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
responsibility 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 principles on standard-
ization established in the Decision on Principles for the
Development of International Standards, Guides and Recom-
mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee.
2. Referenced Documents
2.1 ASTM Standards:
2
C167 Test Methods for Thickness and Density of Blanket or
Batt Thermal Insulations
C168 Terminology Relating to Thermal Insulation
C177 Test Method for Steady-State Heat Flux Measure-
ments and Thermal Transmission Properties by Means of
the Guarded-Hot-Plate Apparatus
C518 Test Method for Steady-State Thermal Transmission
Properties by Means of the Heat Flow Meter Apparatus
C653 Guide for Determination of the Thermal Resistance of
Low-Density Blanket-Type Mineral Fiber Insulation
C739 Specification for Cellulosic Fiber Loose-Fill Thermal
Insulation
C1045 Practice for Calculating Thermal Transmission Prop-
erties Under Steady-State Conditions
C1114 Test Method for Steady-State Thermal Transmission
Properties by Means of the Thin-Heater Apparatus
C1363 Test Method for Thermal Performance of Building
Materials and Envelope Assemblies by Means of a Hot
Box Apparatus
C1373 Practice for Determination of Thermal Resistance of
Attic Insulation Systems Under Simulated Winter Condi-
tions
E2935 Practice for Evaluating Equivalence of Two Testing
Processes
3. Terminology
3.1 Unless otherwise stated, the terms and definitions found
in Terminology C168 are applicable herein.
4. Significance and Use
4.1 The thermal resistance, R, of an insulation is used to
describe its thermal performance.
1
This practice is under the jurisdiction of ASTM Committee C16 on Thermal
Insulation and is the direct responsibility of Subcommittee C16.30 on Thermal
Measurement.
Current edition approved Sept. 1, 2024. Published October 2024. Originally
approved in 1971. Last previous edition approved in 2018 as C687 – 18. DOI:
10.1520/C0687-24.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at www.astm.org/contact. For Annual Book of
ASTM Standards volume information, refer to the standard’s Document Summary
page on the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
4.2 The thermal resistance of an insulation is related to the
density and thickness of the insulation. It is desirable to obtain
test data on thermal resistances at thicknesses and densities
related to the end uses of the product.
4.3 In normal use, the thickness of these products range
from less than 100 mm (4 in.) to greater than 500 mm (20 in.).
Installed densities depend upon the product type, the installed
thickness, the installation equipment used, the installation
techniques, and the geometry of the insulated space.
4.4 Loose-fill insulations provide coverage information us-
ing densities selected by manufacturers to represent the product
settled densities. Generally, it is necessary to know the product
thermal performance at a representative density. Some cover-
age charts utilize multiple densities to show that greater
thickness installations usually result in higher installed densi-
ties. The use of multiple densities can be detected from the
coverage chart by calculating the density for several different
thermal resistance levels. (The density for a given thermal
resistance can be calculated from the coverage chart by
dividing the minimum mass per unit area by the minimum
thickness.) If the calculated densities are significantly different
at different thermal resistances, the multiple density strategy
has been used.
4.5 When applicable specifications or codes do not specify
the nominal thermal resistance level to be used for comparison
purposes, a recommended practice is to use the R
si
(met-
ric) = 3.3 m
2
K/W (R
IP
= 19 [h ft
2
F/Btu]) label density and
thickness for that measurement.
4.6 If the density for test purposes is not available from the
coverage chart, a test density shall be established by use of
applicable specifications and codes or, if none apply, agreement
between the requesting body and the testing organization.
4.7 Generally, thin sections of these materials are not
uniform. Thus, the test thickness must be greater than or equal
to the product’s representative thickness if the results are to be
consistent and typical of use.
NOTE 1—The representative thickness is specific for each product and
is determined by running a series of tests in which the density is held
constant but the thickness is increased. The representative thickness is
defined here as that thickness above which there is no more than a 2 %
change in the resistivity of the product. The representative thickness is a
function of product blown density. In general, as the density decreases, the
representative thickness increases. Fortunately, most products are de-
signed to be blown over a small range of densities. This limited range
yields a range of representative thicknesses between 100 to 200 mm (4 to
8 in.) for most products. To simplify the process for this Practice, the
representative thickness for the C687 tests shall be determined at the
midpoint of the blown density range. Once this is accomplished, all
thermal testing on this product is conducted at a thickness that is greater
or equal to the representative thickness.
4.7.1 For this practice, the minimum test thickness shall be
100 mm (4 in.) or the representative thickness, whichever is
larger. If the test is to represent an installation at a lesser
thickness, the installed thickness shall be used.
4.8 Because of the high cost of construction and operation
of large test equipment, it is impractical to test at the higher
thicknesses at which products are used. For purposes of this
practice, it is acceptable to estimate the thermal resistance at
any thickness from the thermal resistivity obtained from tests
on the product at the minimum test thickness (see 4.7.1) and at
the density expected for the proposed thickness.
4.9 In principle, any of the standard methods for the
determination of thermal resistance are suitable for loose-fill
products. These include Test Methods C177,C518,C1114, and
C1363. 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 otherwise
specified, tests shall be performed for the maximum heat flow
condition, that is, a horizontal specimen with heat flow-up.
4.11 Specimens shall be prepared in a manner consistent
with the intended installation procedure. Products for pneu-
matic installation shall be pneumatically applied (blown), and
products for pour-in-place installation shall be poured into
specimen frames.
4.12 Loosefill insulation installed in attic applications will
have heat flow up during the winter. At winter design condi-
tions in many areas, the winter design temperature difference
will cause convective heat transfer to occur within some
loose-fill insulations. The procedure outlined in Practice C687
is not applicable to that measurement unless a Test Method
C1363 test apparatus is used to reproduce the correct boundary
conditions. To determine how seasonal differences can affect
product performance, use Practice C1373. Practice C1373
measures the expected winter thermal performance of loose-fill
insulation under simulated winter design temperature condi-
tions and provides specimen requirements necessary for that
determination.
5. Apparatus
5.1 Thermal test apparatus used for this practice shall meet
these requirements.
5.1.1 Conformance to Standards—The apparatus shall con-
form to all requirements of the ASTM thermal test method
used.
5.1.2 Size and Error—The apparatus shall be capable of
testing specimens up to at least 150-mm (6-in.) thickness with
an estimated error not greater than 1 % attributed to thickness/
guard dimensions. (Parametric studies using a mathematical
model of the proposed apparatus will give insight to this
evaluation. For example see Table 1 in the 1976 revision of
Test Method C518.
3
)
NOTE 2—Thermal test apparatus in use for this practice have overall
plate dimensions of 457 to 1220 mm (18 to 48 in.) square with metering
areas 152 to 457 mm (6 to 18 in.) square. Other sizes are acceptable if
proper consideration of the size-thickness restrictions as outlined in the
test method are observed in their design. (See Practice C1045 for
additional discussion.)
5.1.3 Temperature—As a minimum, the apparatus shall be
capable of testing at a mean temperature of 23.9°C (75°F) with
a temperature difference of 20 to 28°C (36 to 50°F). The
3
See Table 1, “Maximum Spacing Between Warm and Cold Plates of Heat
Flowmeter Apparatus,” of Test Method C518 – 76 published in 1985 Annual Book
of ASTM Standards, Vol 04.06.
C687 − 24
2
equipment shall be calibrated at the same temperatures as the
test conditions. Some existing test apparatus have been de-
signed to provide measurements over a range of mean tem-
peratures from −20 to 55°C (−4 to 131°F) and for a wider range
of temperature differences.
5.1.4 Humidity—The 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
9°C (48°F) dew point is consistent with the recommended
material conditioning levels.
5.1.5 Orientation and Direction of Heat Flow—The thermal
test apparatus shall be capable of testing horizontal specimens
with heat flow-up. This orientation represents the most adverse
heat flow condition for testing between two solid boundaries.
5.1.6 Thermal Test Specimen Frame—The test frame shall
be sized to match the test apparatus and shall be made of
materials having low thermal conductivity (<0.12 W/m K) and
minimum thickness. A thin, thermally insignificant, screen or
membrane is stretched across the bottom to support the
material. 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 Machine—A blowing apparatus is required
when pneumatically applied specimens are to be tested.
Choose the combination of hopper, blower, and hose size and
length that is representative of common use for the application
of the material to be tested. The following machine specifica-
tions have been developed for use with mineral wool and
cellulosic materials.
5.2.1.1 Mineral Fiber Insulations:
(1) Blowing Machine—A commercial blowing machine
with a design capacity for delivering the subject material at a
rate between 4 and 15 kg (9 to 33 lb)/min.
(2) Blowing Hose—The machine shall utilize 46 m (150 ft)
of typical 75 to 100 mm (3 to 4 in.) diameter flexible, internally
corrugated blowing hose. At least 30 m (100 ft) of the hose
shall be elevated between 3 and 6 m (10 and 20 ft) above the
outlet of the blowing machine to simulate a typical installation
configuration. The hose shall have no more than eight 90°
bends and all bends shall be greater than 1.2-m (4-ft) radius.
Before each sample preparation session, examine the hose for
material remaining from previous blows. Dislodge any remain-
ing material by mechanically agitating the hose when the
machine is running. Repeat as necessary to maintain a clean
hose for each specimen.
NOTE 3—In 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 Insulations:
NOTE 1—Dimensions to match thermal test apparatus.
FIG. 1 Rigid Test Frame
C687 − 24
3
摘要:

ASTM C687 - 24 是用于测定松散填充建筑隔热材料热阻的标准规范,主要针对如纤维素、玻璃纤维或矿棉等松散填充隔热材料在建筑应用中的热性能评估。该规范详细描述了在实验室条件下,通过热流计装置或防护热板装置测量材料热阻的标准测试程序,涵盖样品制备、密度控制、测试条件及数据处理要求。遵循 ASTM C687 标准,可确保松散填充隔热材料的热阻数据具有一致性、可重复性和可靠性,为建筑节能设计、材料选型及能效评估提供重要依据。该标准适用于新建建筑或既有建筑改造中保温隔热层性能的验证,并有助于工程

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作者:那山那人那狗 分类:国外协会 价格:18星币 属性:10 页 大小:521.84KB 格式:PDF 时间:2025-06-25

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