Estimating Feasibility of Regenerating PCM and Desiccant in Room Interior Wall Surfaces Using Pre-dried Air Through an External Desiccant Bed
Abstract
Buildings account for a significant fraction of energy use. Reduction of energy use in buildings has been the subject of research for quite a while to date. Passive means for comfort provision is one way of energy use reduction in buildings. A passive humidity and temperature control requires regeneration of the participating building envelope materials at some point in order for the buffering to be possible when needed. The present work focuses on investigating the potential for regenerating interior building envelope materials of an office that have been enhanced with a desiccant (for moisture buffering) and a PCM (for temperature buffering). The simulation study reveals that with an appropriate design the regeneration of both PCM and desiccant is possible. In winter, the cooling of the PCM takes place at a faster rate because the outdoor air temperatures are highly subdued during the night. The significantly low temperatures, however, are not favorable for the silica gel regeneration but moisture content of as low as 0.04kg/kg is achieved at the fourth hour of regeneration while beyond this hour the moisture content starts to increase. Temperatures are on a decrease towards minimum as dawn approaches. In summer, it is possible to reach about 0.07kg/kg and at the same time being able to freeze PCM that to dispatch about 470W of cooling power for a 10-hour period.
Keywords
Regeneration, Phase change material, Desiccant, Passive humidity and temperature control