Multi-melting-point paraffin-microsphere double glazing for cold-climate buildings: Synergistic optimization of daylighting and winter thermal stability
Energy, cilt.361, 2026 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 361
- Basım Tarihi: 2026
- Doi Numarası: 10.1016/j.energy.2026.141883
- Dergi Adı: Energy
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Applied Science & Technology Source, Compendex, Environment Index, Geobase, INSPEC, Public Affairs Index, Academic Search Ultimate (EBSCO), Engineering Source (EBSCO)
- Anahtar Kelimeler: Building energy conservation, Cold-climate buildings, Daylighting performance, Phase change microsphere, Photothermal synergistic optimization
- Kocaeli Üniversitesi Adresli: Evet
Özet
In cold-climate applications, transparent envelopes must provide daylight and solar gains under severe indoor–outdoor temperature gradients; under these conditions, heat transfer is intensified and winter thermal stability is reduced, so passive photothermal strategies are required to regulate heat flow and maintain daylight availability. A paraffin-microsphere double-glazed envelope was proposed; different phase-change temperatures were selected to combine latent-heat regulation, PCM containment, and distribution stability. Five layer arrangements were evaluated experimentally and numerically through a laboratory-scale photothermal framework validated against indoor midpoint temperatures; the average relative error was 4.48%. The arrangements represented three design categories: a 50:50 mixture of 9°C and 14°C paraffin microspheres, a two-layer paraffin sequence, and glass–paraffin sequences defined by the 5-mm glass-layer position inside the 9°C/14°C paraffin-microsphere assembly. The optical maximum was obtained from the 50:50 mixed 9°C/14°C paraffin-microsphere arrangement, as shown by 563.28 lx average illuminance and 0.57 maximum transmittance. In contrast, the integrated photothermal optimum was achieved by the 5-mm glass–9°C-14°C paraffin-microsphere sequence; midpoint-temperature fluctuation was limited to 1.97 K, fluctuation was reduced by 73.7%, a 99.87% DF-compliant area was obtained, and indoor illuminance increased by 86 lx (25%) relative to the reference case. An 8 mm paraffin-microsphere double-glazed envelope, defined by a 50:50 9°C/14°C paraffin ratio and the 5-mm glass–9°C-14°C sequence, is recommended for passive cold-climate transparent-envelope design, supported by limited room-side heat flux (52.05–76.23 W m−2), temperature stabilization, daylight adequacy, and PCM containment.