Conference Paper
Proceedings of BSA Conference 2024: Sixth Conference of IBPSA-Italy
Examining Indoor Humidity Ratio in Response to Varying Window-To-Wall Ratio and Ventilation in Indian Climate Zones for Earth-Plaster Based Dwellings
Examining Indoor Humidity Ratio in Response to Varying Window-To-Wall Ratio and Ventilation in Indian Climate Zones for Earth-Plaster Based Dwellings
Suchi Priyadarshani, Monto ManiDOI: https://doi.org/10.13124/9788860462022_54Abstract: Indoor Earth-based plasters in buildings offer indoor humidity regulation through moisture buffering. This study examines the applicability of using earth-based plaster indoors as a passive strategy for regulating indoor humidity for occupant comfort, using a simulation-based approach. BESTEST model geometry was used to simulate indoor T/RH conditions with varying window-to-wall ratio (WWR) and air changes per hour (ACH) for Indian climate zones using EMPD (Effective Moisture Penetration Depth) model in DesignBuilder tool. Experimentally derived material properties of earth-plaster were used as input to the model. The results revealed that the surface area available for moisture sorption/desorption or WWR is critical in determining the moisture buffering potential. High WWR leads to low surface area available for moisture buffering, resulting in high diurnal indoor Humidity Ratio peaks. Also, air changes per hour (ACH) have a significant bearing on moisture buffering. As the ACH increases, the peaks in indoor HR increase and become closer to the outdoor HR. In this chapter, monthly mean indoor HR for the given geometry was computed for the 5 climate zones of India. These results were examined vis-à-vis indoor comfort Humidity Ratio recommendations for comfort (accounting for thermal, skin, and respiratory comfort) for occupants in the rural Indian setup as reported in our previous work. The results suggest that earth-plaster for moisture buffering can be effectively used in Warm and Humid, Hot and Dry, and Composite climate zones of India. Using this strategy in Temperate and Cold climate zones was not found effective. Earth-based plasters are derived from natural soil, and their use can avoid cementitious (energy and carbon-intensive) material and support occupants' wellness simultaneously. Pages: 445 - 452 Paper: