Title

Phase-change material wallboard for distributed thermal storage in buildings

Abstract

Development and testing were conducted for a prototype phase-change material (PCM) wallboard to enhance the thermal energy storage capacity of buildings with particular interest in peak load shifting. Most important, it was determined that small-scale differential scanning calorimetry can adequately predict (within 9%) the performance of PCM wallboard when installed in full-scale applications. Initial PCM wallboard developmental tests were conducted on a small scale using a differential scanning calorimeter (DSC). The DSC measured the melting point and latent heat of selected phase-change materials and some prototype PCM wallboard. Based on these initial DSC tests, coconut fatty acid was selected for the room-scale PCM wallboard tests due to its favorable melting and freezing temperature range. At a loading of 25% by weight, the DSC measured an average latent heat of 9.57 Btu/lb (22.26 J/g) for the PCM wallboard. The average melting point was 76.8 °F (24.9 °C). Additional tests were conducted to ascertain DSC measurement reproducibility, spatial uniformity of PCM loading, and PCM high-temperature stability. Room-scale tests showed that the PCM wallboard had an average thermal storage capacity of 10.4 Btu/lb (24.2 J/g). This varied by only 8.7% compared to the latent heat recorded by the DSC. Thus expensive, large-scale testing may not be required until a PCM wallboard product is well along in development. Thus far, the PCM wallboard development work has experimentally shown that the concept is workable on a large scale and that phase-change material can be successfully integrated and distributed within a building with a significant thermal storage effect. However, to obtain the magnitude of storage required, more work is needed to identify or develop new materials with greater latent heat capacity while keeping the melting/freezing range between 72 °F (22.2 °C) and 79 °F (26.1 °C).

Publication Date

12-1-1993

Publication Title

ASHRAE Transactions

Volume

99

Issue

pt 2

Number of Pages

339-346

Document Type

Article

Identifier

scopus

Socpus ID

0027885793 (Scopus)

Source API URL

https://api.elsevier.com/content/abstract/scopus_id/0027885793

This document is currently not available here.

Share

COinS