ASTM C1784-20
(Test Method)Standard Test Method for Using a Heat Flow Meter Apparatus for Measuring Thermal Storage Properties of Phase Change Materials and Products
Standard Test Method for Using a Heat Flow Meter Apparatus for Measuring Thermal Storage Properties of Phase Change Materials and Products
SIGNIFICANCE AND USE
5.1 Materials used in building envelopes to enhance energy efficiency, including PCM products used for thermal insulation, thermal control, and thermal storage, are subjected to transient thermal environments, including transient or cyclic boundary temperature conditions. This test method is intended to enable meaningful PCM product classification, as steady-state thermal conductivity alone is not sufficient to characterize PCMs.
Note 3: This test method defines a dynamic test protocol for complex products or composites containing PCMs. Due to the macroscopic structure of these products or composites, conventional measurements using a Differential Scanning Calorimeter (DSC) as specified in E793 and E967, which use very small specimens, are not necessarily representative of the relationship between temperature and enthalpy of full-scale PCM products due to the specimen size limitation.
5.2 Dynamic measurements of the thermal performance of PCM products shall only be performed by qualified personnel with understanding of heat transfer and error propagation. Familiarity with the configuration of both the apparatus and the product is necessary.
5.3 This test method focuses on testing PCM products used in engineering applications, including in building envelopes to enhance the thermal performance of insulation systems.
5.3.1 Applications of PCM in building envelopes take multiple forms, including: dispersed in, or otherwise combined with, a thermal insulation material; a separate object implemented in the building envelope as boards or membranes containing concentrated PCM that operates in conjunction with a thermal insulation material. Both of these forms enhance the performance of the structure when exposed to dynamic, that is, fluctuating, boundary temperature conditions.
5.3.2 PCMs can be studied in a variety of forms: as the original “pure” PCM; as a composite containing PCM and other embedded materials to enhance thermal performance; as a product cont...
SCOPE
1.1 This test method covers the measurement of non-steady-state heat flow into or out of a flat slab specimen to determine the stored energy (that is, enthalpy) change as a function of temperature using a heat flow meter apparatus (HFMA).
1.2 In particular, this test method is intended to measure the sensible and latent heat storage capacity for products incorporating phase-change materials (PCM).
1.2.1 The storage capacity of a PCM is well defined via four parameters: specific heats of both solid and liquid phases, phase change temperature(s) and phase change enthalpy (1).2
1.3 To more accurately predict thermal performance, information about the PCM products’ performance under dynamic conditions is needed to supplement the properties (thermal conductivity) measured under steady-state conditions.
Note 1: This test method defines a dynamic test protocol for products or composites containing PCMs. Due to the macroscopic structure of these products or composites, small specimen sizes used in conventional Differential Scanning Calorimeter (DSC) measurements, as specified in E793 and E967, are not necessarily representative of the relationship between temperature and enthalpy of full-scale PCM products.
1.4 This test method is based upon the HFMA technology used for Test Method C518 but includes modifications for specific heat and enthalpy change measurements for PCM products as outlined in this test method.
1.5 Heat flow measurements are required at both the top and bottom HFMA plates for this test method. Therefore, this test method applies only to HFMAs that are equipped with at least one heat flux transducer on each of the two plates and that have the capability for computerized data acquisition and temperature control systems. Further, the amount of energy flowing through the transducers must be measureable at all points in time. Therefore, the transducer output shall never be saturated during a test. ...
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Standards Content (Sample)
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.
Designation: C1784 − 20
Standard Test Method for
Using a Heat Flow Meter Apparatus for Measuring Thermal
Storage Properties of Phase Change Materials and
1
Products
This standard is issued under the fixed designation C1784; 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 through the transducers must be measureable at all points in
time. Therefore, the transducer output shall never be saturated
1.1 Thistestmethodcoversthemeasurementofnon-steady-
during a test.
state heat flow into or out of a flat slab specimen to determine
1.6 This test method makes a series of measurements to
the stored energy (that is, enthalpy) change as a function of
determine the thermal energy storage of a test specimen over a
temperature using a heat flow meter apparatus (HFMA).
temperature range. First, both HFMA plates are held at the
1.2 In particular, this test method is intended to measure the
same constant temperature until steady state is achieved.
sensible and latent heat storage capacity for products incorpo-
Steadystateisdefinedbythereductionintheamountofenergy
rating phase-change materials (PCM).
entering the specimen from both plates to a very small and
1.2.1 ThestoragecapacityofaPCMiswelldefinedviafour
nearly constant value. Next, both plate temperatures are
parameters: specific heats of both solid and liquid phases,
changed by identical amounts and held at the new temperature
2
phase change temperature(s) and phase change enthalpy (1).
until steady state is again achieved. The energy absorbed or
released by the specimen from the time of the temperature
1.3 To more accurately predict thermal performance, infor-
change until steady state is again achieved will be recorded.
mation about the PCM products’ performance under dynamic
Using a series of temperature step changes, the cumulative
conditions is needed to supplement the properties (thermal
enthalpy stored or released over a certain temperature range is
conductivity) measured under steady-state conditions.
determined.
NOTE 1—This test method defines a dynamic test protocol for products
1.6.1 The specific heats of the solid and liquid phases are
orcompositescontainingPCMs.Duetothemacroscopicstructureofthese
products or composites, small specimen sizes used in conventional determined from the slope of the temperature-dependant en-
Differential Scanning Calorimeter (DSC) measurements, as specified in
thalpy function during sensible heating/cooling, before and
E793 and E967, are not necessarily representative of the relationship
after the phase change process.
between temperature and enthalpy of full-scale PCM products.
1.7 Calibration of the HFMA to determine the ‘correction
1.4 This test method is based upon the HFMA technology
factors’ for the energy stored within the plate heat flux
used for Test Method C518 but includes modifications for
transducers and any material placed between the test specimen
specific heat and enthalpy change measurements for PCM
and the HFMAplates must be performed following AnnexA1.
products as outlined in this test method.
These correction factors are functions of the beginning and
1.5 Heatflowmeasurementsarerequiredatboththetopand ending temperatures for each step, as described in Annex A1.
bottom HFMA plates for this test method. Therefore, this test
1.8 This test method applies to PCMs and composites,
method applies only to HFMAs that are equipped with at least
products and systems incorporating PCMs, including those
oneheatfluxtransduceroneachofthetwoplatesandthathave
with PCM dispersed in or combined with a thermal insulation
the capability for computerized data acquisition and tempera-
material, boards or membranes containing concentrated or
ture control systems. Further, the amount of energy flowing
dispersed PCM, etc. Specific examples include solid PCM
composites and products, loose blended materials incorporat-
ing PCMs, and discretely contained PCM.
1
ThistestmethodisunderthejurisdictionofASTMCommitteeC16onThermal
1.9 This test method may be used to characterize material
Insulation and is the direct responsibility of Subcommittee C16.30 on Thermal
properties, which may or may not be representative of actual
Measurement.
conditions of use.
Current edition approved April 1, 2020. Published May 2020. Originally
approved in 2013. Last previous edition approved in 2014 as C1784 – 14. DOI:
1.10 The values stated in SI units are to be regarded as
10.1520/C1784-20.
2
standard. No ot
...
This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: C1784 − 14 C1784 − 20
Standard Test Method for
Using a Heat Flow Meter Apparatus for Measuring Thermal
Storage Properties of Phase Change Materials and
1
Products
This standard is issued under the fixed designation C1784; 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 test method covers the measurement of non-steady-state heat flow into or out of a flat slab specimen to determine the
stored energy (that is, enthalpy) change as a function of temperature using a heat flow meter apparatus (HFMA).
1.2 In particular, this test method is intended to measure the sensible and latent heat storage capacity for products incorporating
phase-change materials (PCM).
1.2.1 The storage capacity of a PCM is well defined via four parameters: specific heats of both solid and liquid phases, phase
2
change temperature(s) and phase change enthalpy (1).
1.3 To more accurately predict thermal performance, information about the PCM products’ performance under dynamic
conditions is needed to supplement the properties (thermal conductivity) measured under steady-state conditions.
NOTE 1—This test method defines a dynamic test protocol for products or composites containing PCMs. Due to the macroscopic structure of these
products or composites, small specimen sizes used in conventional Differential Scanning Calorimeter (DSC) measurements, as specified in E793 and
E967, are not necessarily representative of the relationship between temperature and enthalpy of full-scale PCM products.
1.4 This test method is based upon the HFMA technology used for Test Method C518 but includes modifications for specific
heat and enthalpy change measurements for PCM products as outlined in this test method.
1.5 Heat flow measurements are required at both the top and bottom HFMA plates for this test method. Therefore, this test
method applies only to HFMAs that are equipped with at least one heat flux transducer on each of the two plates and that have
the capability for computerized data acquisition and temperature control systems. Further, the amount of energy flowing through
the transducers must be measureable at all points in time. Therefore, the transducer output shall never be saturated during a test.
1.6 This test method makes a series of measurements to determine the thermal energy storage of a test specimen over a
temperature range. First, both HFMA plates are held at the same constant temperature until steady state is achieved. Steady state
is defined by the reduction in the amount of energy entering the specimen from both plates to a very small and nearly constant
value. Next, both plate temperatures are changed by identical amounts and held at the new temperature until steady state is again
achieved. The energy absorbed or released by the specimen from the time of the temperature change until steady state is again
achieved will be recorded. Using a series of temperature step changes, the cumulative enthalpy stored or released over a certain
temperature range is determined.
1.6.1 The specific heats of the solid and liquid phases are determined from the slope of the temperature-dependant enthalpy
function during sensible heating/cooling, before and after the phase change process.
1.7 Calibration of the HFMA to determine the ‘correction factors’ for the energy stored within the plate heat flux transducers
and any material placed between the test specimen and the HFMA plates must be performed following Annex A1. These correction
factors are functions of the beginning and ending temperatures for each step, as described in Annex A1.
1.8 This test method applies to PCMs and composites, products and systems incorporating PCMs, including those with PCM
dispersed in or combined with a thermal insulation material, boards or membranes containing concentrated or dispersed PCM, etc.
Specific examples include solid PCM composites and products, loose blended materials incorporating PCMs, and discretely
contained PCM.
1
This test method 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 Oct. 1, 2014April 1, 2020. Published December 2014May 2020. Originally approved in 2013. Last previous edition approved in 20132014 as
C1784C1784 – 14.-13. DO
...
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