1.1This test method covers the measurement of non-steady-state thermal transmission into or out of a specimen to measure the energy storage corresponding to a given temperature step using a heat flow meter apparatus. 1.2In particular, this test method is intended to measure the energy storage for a specimen incorporating phase-change energy storage. 1.3Materials used in building envelopes to enhance energy efficiency, including Phase Change Material (PCM)- enhanced materials used for thermal insulation, thermal control, and thermal storage, are subjected to transient thermal environments, including transient or cyclic boundary temperature conditions. 1.4 To more accurately predict thermal performance, information about the PCM-enhanced material performance under dynamic conditions is needed to supplement the property values measured under steady-state conditions. NOTE: This Test Method defines a dynamic test protocol for complex materials or composites containing PCMs. Due to the macroscopic structure of these materials or composites, conventional measurements using a Differential Scanning Calorimeter (DSC) as specified in ASTM E793 and ASTM do not provide sufficient accuracy regarding the relationship between temperature and heat storage. 1.5The dynamic performance characterization is intended to enable meaningful PCM-enhanced material labeling and classification. 1.6This test method is based upon the technology of Test Method C 518 but includes modifications for phase change-enhanced insulation materials as outlined in this test method. 1.7This test method shall be used in conjunction with Practice C 1045 and Practice C 1058. 1.8This Test Method applies only to the 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. 1.9 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.10This 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 appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
Phase change materials must be measured using dynamic test methods. Equipment developed for steady state heat flux measurements can be adapted for this purpose. The resulting values can be used to develop a useful rating method for phase change materials.
Keywords13.1 Phase Change Material, Energy Storage, Latent Heat
The title and scope are in draft form and are under development within this ASTM Committee.Back to Top
Ballot Item Approved as C1784-2013 and Pending Publication