Due to their thermal performance,domed roofs are one of the passive solutions that affect energy consumption in buildings.The thermal performance of domed roofs has been investigated in many naturally ventilated space...Due to their thermal performance,domed roofs are one of the passive solutions that affect energy consumption in buildings.The thermal performance of domed roofs has been investigated in many naturally ventilated spaces.However,few studies have discussed their performance in conditioned spaces.Therefore,this study introduces a computational comparison between domed and flat roofs to investigate their impact on thermal comfort inside a conditioned mosque.At an earlier stage,field measurements were carried out inside a Bahraini mosque to acquire its indoor air conditions during the summer period of 2021,in addition to validating the computational model.The findings of this study confirm that,under mechanical cooling conditions,the flat roof offers a lower indoor temperature than the domed roof by 0.4℃and 0.1℃for open and closed doors,respectively.Similarly,the air velocity is lower by approximately 0.01 m/s for both door modes.The overall PMV values of the flat roof are also lower by 0.07 and 0.01,while the PPD values are lower by 0.20,and 0.34 for open and closed doors,respectively.Based on these small differences,it can be concluded that the thermal performance of both roofing systems behaves equally in conditioned spaces.However,the air patterns are substantially different,the overall thermal performance is similar.This similarity drives building designers to rethink the thermal performance of the domed roofs in air-conditioned spaces with such a hot climate,regardless of their aesthetic and acoustical behaviour.展开更多
It has been a focus to reduce the energy consumption and improve the space heating performance of high-altitude buildings in winter seasons. In view of the abundant solar energy resources of the high-altitude region, ...It has been a focus to reduce the energy consumption and improve the space heating performance of high-altitude buildings in winter seasons. In view of the abundant solar energy resources of the high-altitude region, the establishment of passive solar houses should be an effective strategy to deal with the problem of thermal comfort. Both window to wall ratio(WWR) and sunspace depth are of vital importance to determine the thermal comfort level of passive solar houses, while there are limited studies on analyzing their impacts on passive solar houses in high-altitude regions. Therefore, this study is designed to examine how WWR and sunspace depth affect space heating of passive solar houses in the Qinghai-Tibetan region. To be specific, the hourly radiation temperature variations and percentages of dissatisfaction of the residential building with different sunspace depth/WWR(including 0.9 m/33%, 0.9 m/45%, 0.9 m/60%, 1.2 m/33% and 1.5 m/33%) were quantitatively examined. Results indicated that under the condition of 0.9 m/45%, the overall average radiation temperature of the building was approximately 16°C during the entire heating season, which could better satisfy the heating requirements. Meanwhile, the average temperature was higher, and the thermal comfort level was better under the ratio of 45% or the depth of 1.5 m, when only an individual factor in either ratio or depth was considered. These findings can provide references for the determination of dimensions of passive solar houses in high-altitude regions.展开更多
文摘Due to their thermal performance,domed roofs are one of the passive solutions that affect energy consumption in buildings.The thermal performance of domed roofs has been investigated in many naturally ventilated spaces.However,few studies have discussed their performance in conditioned spaces.Therefore,this study introduces a computational comparison between domed and flat roofs to investigate their impact on thermal comfort inside a conditioned mosque.At an earlier stage,field measurements were carried out inside a Bahraini mosque to acquire its indoor air conditions during the summer period of 2021,in addition to validating the computational model.The findings of this study confirm that,under mechanical cooling conditions,the flat roof offers a lower indoor temperature than the domed roof by 0.4℃and 0.1℃for open and closed doors,respectively.Similarly,the air velocity is lower by approximately 0.01 m/s for both door modes.The overall PMV values of the flat roof are also lower by 0.07 and 0.01,while the PPD values are lower by 0.20,and 0.34 for open and closed doors,respectively.Based on these small differences,it can be concluded that the thermal performance of both roofing systems behaves equally in conditioned spaces.However,the air patterns are substantially different,the overall thermal performance is similar.This similarity drives building designers to rethink the thermal performance of the domed roofs in air-conditioned spaces with such a hot climate,regardless of their aesthetic and acoustical behaviour.
基金supported by National Key R&D Program of China-Technical System and Key Technology Development of Nearly Zero Energy Building (No. 2017YFC0702600)the opening Funds of State Key Laboratory of Building Safety and Built Environment National Engineering Research Center of Building Technology (BSBE2017-08)+1 种基金the Major Basic Research Development and Transformation Program of Qinghai province (No. 2016-NN-141 )the Fundamental Research Funds for the Central Universities (No. 2018MS103, 2018MS108 and 2017MS119 )
文摘It has been a focus to reduce the energy consumption and improve the space heating performance of high-altitude buildings in winter seasons. In view of the abundant solar energy resources of the high-altitude region, the establishment of passive solar houses should be an effective strategy to deal with the problem of thermal comfort. Both window to wall ratio(WWR) and sunspace depth are of vital importance to determine the thermal comfort level of passive solar houses, while there are limited studies on analyzing their impacts on passive solar houses in high-altitude regions. Therefore, this study is designed to examine how WWR and sunspace depth affect space heating of passive solar houses in the Qinghai-Tibetan region. To be specific, the hourly radiation temperature variations and percentages of dissatisfaction of the residential building with different sunspace depth/WWR(including 0.9 m/33%, 0.9 m/45%, 0.9 m/60%, 1.2 m/33% and 1.5 m/33%) were quantitatively examined. Results indicated that under the condition of 0.9 m/45%, the overall average radiation temperature of the building was approximately 16°C during the entire heating season, which could better satisfy the heating requirements. Meanwhile, the average temperature was higher, and the thermal comfort level was better under the ratio of 45% or the depth of 1.5 m, when only an individual factor in either ratio or depth was considered. These findings can provide references for the determination of dimensions of passive solar houses in high-altitude regions.
