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
The paper aims to investigate the potential of a water body to influence in lowering the warmth in the city of Sao Jose do Rio Preto, Brazil, due to the evaporative cooling effects. In order to verify its potential, t...The paper aims to investigate the potential of a water body to influence in lowering the warmth in the city of Sao Jose do Rio Preto, Brazil, due to the evaporative cooling effects. In order to verify its potential, three collecting points of temperature and humidity were placed in an urban area close to the municipal dam. The first one was placed on the dam margin, the second one, 50 m distant of the margin and, the third one, 100 m distant. The data were taken during December 2010 and then compared to the climate data of the Climate Station of CIIAGRO-Integrated Center of Agro Meteorological. The results show that the closer the collection point is to the water body, and the lower is the temperature variation. The humidity taxes verified at the closest point to the water body indicate values higher than those ones collected at the most distant point. The insertion of moisture through the water bodies in an urban environment demonstrated to be a strategy that improved the thermal conditions and has to be considered for urban planners to establish strategies of urban occupation.展开更多
Evaporative cooling is a widely used air cooling technique. In this method, evaporation of a liquid in the surrounding air cools the air in contact with it. In the current investigation, numerical simulations are card...Evaporative cooling is a widely used air cooling technique. In this method, evaporation of a liquid in the surrounding air cools the air in contact with it. In the current investigation, numerical simulations are carded out to visualize the evaporation and dynamics of tiny water droplets of different diameters in a long air duct. The effect of initial droplet size on the temperature and relative humidity distribution of the air stream in the duct is investigated. Three different initial conditions of air are considered to verify the influence of ambient conditions. Droplet spray patterns are also analyzed to identify the suitable locations for the spray nozzles within the duct. The resuits obtained are displayed in a series of plots to provide a clear understanding of the evaporative cooling process as well as the droplet dynamics within the ducts.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.
文摘The paper aims to investigate the potential of a water body to influence in lowering the warmth in the city of Sao Jose do Rio Preto, Brazil, due to the evaporative cooling effects. In order to verify its potential, three collecting points of temperature and humidity were placed in an urban area close to the municipal dam. The first one was placed on the dam margin, the second one, 50 m distant of the margin and, the third one, 100 m distant. The data were taken during December 2010 and then compared to the climate data of the Climate Station of CIIAGRO-Integrated Center of Agro Meteorological. The results show that the closer the collection point is to the water body, and the lower is the temperature variation. The humidity taxes verified at the closest point to the water body indicate values higher than those ones collected at the most distant point. The insertion of moisture through the water bodies in an urban environment demonstrated to be a strategy that improved the thermal conditions and has to be considered for urban planners to establish strategies of urban occupation.
基金supported by the Ministry of Education, Science Technology (MEST) and Korea Institute for Advancement of Technology (KIAT) through the Human Resource Training Project for Regional Innovation
文摘Evaporative cooling is a widely used air cooling technique. In this method, evaporation of a liquid in the surrounding air cools the air in contact with it. In the current investigation, numerical simulations are carded out to visualize the evaporation and dynamics of tiny water droplets of different diameters in a long air duct. The effect of initial droplet size on the temperature and relative humidity distribution of the air stream in the duct is investigated. Three different initial conditions of air are considered to verify the influence of ambient conditions. Droplet spray patterns are also analyzed to identify the suitable locations for the spray nozzles within the duct. The resuits obtained are displayed in a series of plots to provide a clear understanding of the evaporative cooling process as well as the droplet dynamics within the ducts.
