The rapid commercialization of Phase Change Materials(PCMs)for HVAC applications effectively leverages ambient temperature fluctuations to meet growing energy demands in buildings.This study outlines a systematic appr...The rapid commercialization of Phase Change Materials(PCMs)for HVAC applications effectively leverages ambient temperature fluctuations to meet growing energy demands in buildings.This study outlines a systematic approach to passively integrate PCM into building roofs for cooling load reduction.The process involves PCM selection,characterization,analysis of melting front propagation,and thermal performance assessment.Thermal/digital imaging approach tracks the melting front's propagation,revealing significant natural convection due to heat flux from modules bottom surface.Melting front propagation occurs primarily in one dimension.Two identical roof slab units are fabricated and tested in Rupnagar City,India,for assessing thermal performance,with one unit equipped with PCM(PSU)and the other as a conventional reinforced slab unit(CSU).Various energetic and thermal performance metrics,including Maximum Temperature Reduction(MTR),Operative Temperature Difference(OTD),Heat transfer,electricity cost savings(Esc),Discomfort Hours Reduction(DHR),and Maximum Heat Gain Reduction(MHGR),are evaluated.PCM integration results in a significant MTR of 4℃and a 60%reduction in heat flux compared to the conventional unit.Moreover,the PCM room exhibits an 11.2%and 34.8%enhancement in thermal comfort,as indicated by DHR and MHGR,respectively,compared to the reference unit.In addition,considering heating and cooling spaces,it offers a maximum daily saving of 0.06 USD/(kWh·m^(2)).These findings highlight PCM's potential to mitigate temperature fluctuations,enhance thermal comfort,and reduce energy consumption in severe climatic conditions.展开更多
文摘The rapid commercialization of Phase Change Materials(PCMs)for HVAC applications effectively leverages ambient temperature fluctuations to meet growing energy demands in buildings.This study outlines a systematic approach to passively integrate PCM into building roofs for cooling load reduction.The process involves PCM selection,characterization,analysis of melting front propagation,and thermal performance assessment.Thermal/digital imaging approach tracks the melting front's propagation,revealing significant natural convection due to heat flux from modules bottom surface.Melting front propagation occurs primarily in one dimension.Two identical roof slab units are fabricated and tested in Rupnagar City,India,for assessing thermal performance,with one unit equipped with PCM(PSU)and the other as a conventional reinforced slab unit(CSU).Various energetic and thermal performance metrics,including Maximum Temperature Reduction(MTR),Operative Temperature Difference(OTD),Heat transfer,electricity cost savings(Esc),Discomfort Hours Reduction(DHR),and Maximum Heat Gain Reduction(MHGR),are evaluated.PCM integration results in a significant MTR of 4℃and a 60%reduction in heat flux compared to the conventional unit.Moreover,the PCM room exhibits an 11.2%and 34.8%enhancement in thermal comfort,as indicated by DHR and MHGR,respectively,compared to the reference unit.In addition,considering heating and cooling spaces,it offers a maximum daily saving of 0.06 USD/(kWh·m^(2)).These findings highlight PCM's potential to mitigate temperature fluctuations,enhance thermal comfort,and reduce energy consumption in severe climatic conditions.
