Investigation of the thermal performance of a passive solar test-room with wall latent heat storage
Abstract
An experimental and numerical simulation study is presented of the application of phase change materials (PCM) in building envelope components for thermal storage in a passive solar test-room. Gypsum board impregnated with a phase change material was used. The experimental study was conducted in a full-scale outdoor test-room with the PCM gypsum board as inside wall lining. An explicit finite difference model was developed to simulate the transient heat transfer process in the walls. Reasonable agreement between the simulation and the experimental results was observed. It was shown that the utilization of PCM gypsum board in a passive solar building may reduce the maximum room temperature by about 4 °C during the daytime and can reduce the heating load at night significantly.
References (8)
- D. Feldman et al.
Obtaining an energy storing building material by direct incorporation of an organic phase change material in gypsum wallboard
Solar Energy Materials
(1991) - D. Feldman et al.
Energy storage composite with an organic phase change material
Solar Energy Materials
(1989) - D. Feldman et al.
Fatty acids and their mixtures as phase change materials for thermal energy storage
Solar Energy Materials
(1989) - D.W. Hawes
Latent heat storage in concrete
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