Passive strategies for acclimatization of buildings have been studied by several authors in many countries, especially the evaporative and radiant cooling techniques. Fiber cement tiles are very common in popular cons...Passive strategies for acclimatization of buildings have been studied by several authors in many countries, especially the evaporative and radiant cooling techniques. Fiber cement tiles are very common in popular constructions due to their low cost. However, they have over twice of the value thermal transmittance indicated to this bioclimatic zone according to Brazilian guidelines. The objective is to present an alternative to reduce high temperatures on fiber cement tiles. In this paper, the monitoring of passive cooling of roofing during the spring season in a city with subtropical climate is described. Single and combined reflective and evaporative cooling systems were studied in different environmental conditions. Internal surface temperatures of tiles were monitored together with weather variables. Results show a decrease of about 6 ℃, 9 ℃, 10 ℃ and 11 ℃ as compared to the original tiles according to environment conditions and the combined passive cooling techniques. These results allow for the conclusion that the use of passive cooling techniques opens up new possibilities to attenuate the internal surface temperatures of tiles and to consequently decrease the roofing solar heat gain into buildings, thus, providing less air cooling energy consumption.展开更多
Energy demand is growing significantly worldwide to create thermal comfort in buildings.Air-conditioning is contributing to energy consumption at a massive scale in the residential and commercial sectors.The roof is o...Energy demand is growing significantly worldwide to create thermal comfort in buildings.Air-conditioning is contributing to energy consumption at a massive scale in the residential and commercial sectors.The roof is one of the most critical components of the building envelopes,and it achieved maximum heat gain in summer,and it covered nearly 20-25%of overall urban surface areas.In this respect,cool roofs are considered one of the sustainable solutions to maintain thermal comfort in buildings.The results achieved from the literature review indicate that cool roof application reduced energy use in the buildings and a useful tool to mitigate Urban Heat Island(UHI)effect.This paper summarizes cool roof thermal performance with different types of surface coatings in different climatic zones for buildings with additional benefits,limitations,and recommendations for future research work.The results of this review can be helpful for engineers,researchers,dwellers,and architectures to have a good understanding of the benefits of cool roofs to mitigate energy consumption demand in dwelling in a sustainable,cost-effective,and energy-efficient way.The average energy-saving effect of the roof is expressed from 15%to 35.7%in different climatic zones(Temperate,Tropical,Composite,Hot and Warm-Humid)as per the literature survey results.Also,the average roof surface temperature reduction is possible from 1.4℃ to up to 4.7℃ using cool roof technology.展开更多
文摘Passive strategies for acclimatization of buildings have been studied by several authors in many countries, especially the evaporative and radiant cooling techniques. Fiber cement tiles are very common in popular constructions due to their low cost. However, they have over twice of the value thermal transmittance indicated to this bioclimatic zone according to Brazilian guidelines. The objective is to present an alternative to reduce high temperatures on fiber cement tiles. In this paper, the monitoring of passive cooling of roofing during the spring season in a city with subtropical climate is described. Single and combined reflective and evaporative cooling systems were studied in different environmental conditions. Internal surface temperatures of tiles were monitored together with weather variables. Results show a decrease of about 6 ℃, 9 ℃, 10 ℃ and 11 ℃ as compared to the original tiles according to environment conditions and the combined passive cooling techniques. These results allow for the conclusion that the use of passive cooling techniques opens up new possibilities to attenuate the internal surface temperatures of tiles and to consequently decrease the roofing solar heat gain into buildings, thus, providing less air cooling energy consumption.
基金Acknowledgement I would like to express my sincere gratitude to Late Dr.S.P.Singh for the continuous support of my research work for his patience,in-spiration,interest,and immense knowledge.I could not have imagined having a better advisor and mentor for this research article.
文摘Energy demand is growing significantly worldwide to create thermal comfort in buildings.Air-conditioning is contributing to energy consumption at a massive scale in the residential and commercial sectors.The roof is one of the most critical components of the building envelopes,and it achieved maximum heat gain in summer,and it covered nearly 20-25%of overall urban surface areas.In this respect,cool roofs are considered one of the sustainable solutions to maintain thermal comfort in buildings.The results achieved from the literature review indicate that cool roof application reduced energy use in the buildings and a useful tool to mitigate Urban Heat Island(UHI)effect.This paper summarizes cool roof thermal performance with different types of surface coatings in different climatic zones for buildings with additional benefits,limitations,and recommendations for future research work.The results of this review can be helpful for engineers,researchers,dwellers,and architectures to have a good understanding of the benefits of cool roofs to mitigate energy consumption demand in dwelling in a sustainable,cost-effective,and energy-efficient way.The average energy-saving effect of the roof is expressed from 15%to 35.7%in different climatic zones(Temperate,Tropical,Composite,Hot and Warm-Humid)as per the literature survey results.Also,the average roof surface temperature reduction is possible from 1.4℃ to up to 4.7℃ using cool roof technology.
