raw · papers · ingested 2026-07-02
PCMs integrated into transparent building elements: A review (Mater. Renew. Sustain. Energy 2015)
confidence: high
Source: https://link.springer.com/article/10.1007/s40243-015-0047-8
Source: Materials for Renewable and Sustainable Energy (Springer) 2015, doi:10.1007/s40243-015-0047-8. Credibility: High (peer-reviewed review; the single best integration/encapsulation taxonomy found).
Integration methods (packaging taxonomy)
- Between-pane fill — PCM directly in the cavity of a double-glazed unit.
- Container behind glazing — PCM in sealed transparent plastic containers, ~10 mm air gaps behind double glazing.
- Glass blocks/bricks — hollow translucent blocks filled with PCM as thermal-storage wall elements.
- Translucent PMMA / polycarbonate panels — PCM inside a plastic panel in a glass facade.
Material selection is optics-first
- Only organic PCMs and high-water-content salt hydrates are transparent as both solid and liquid.
- CaCl2·6H2O (24–29 °C, 192 J/g) sealed in clear polycarbonate is the dominant translucent packaging.
- Stearic acid noted as transparent insulation; paraffin composites also used.
Products & durability
- GlassX (CaCl2·6H2O in polycarbonate, up to 4268 kJ/m², 30–50% load-reduction claim); Delta-Cool 28 in PMMA facade panels.
- Supercooling is the main salt-hydrate failure mode → nucleators/thickeners. One formulation showed no property change after 5,650 melt/freeze cycles.
- Limits: incomplete nighttime discharge; low thermal conductivity 0.15–0.5 W/mK caps usable latent capacity.