La influencia de las repisas de luz en el aprovechamiento de la luz natural bajo obstrucción

The research considers the hypothesis that the use of the device known as “light shelf” could contribute to optimize internal natural light distribution and control, improving visual comfort and increasing the building´s energy efficiency. The purpose of the inquiry was to evaluate the device’s influence combined with different types of glasses in condition of external obstruction, resembling the reality of the urbanization model with skyscrapers. Three Brazilian cities in different latitudes were chosen, where a simulation of an office building with windows having different obstruction percentages of the celestial sphere took place. With the help of Daysim software, we analyzed the Useful Daylight Illuminances –UDI, verifying that the increase of vertical buildings in urban centers –the usual model in Brazilian cities- could interfere in the quality of light of the internal atmosphere.A investigação considera a hipótese de que o uso do dispositivo prateleira de luz pode contribuir para aperfeiçoar a distribuição e o controle da luz natural interna, o que melhoraria o conforto visual e aumentaria a eficiência energética do edifício. O objetivo da pesquisa foi avaliar a influência desse dispositivo combinado com diferentes tipos de vidro em condições de obstrução externa, aproximando-se da realidade dos centros urbanos verticalizados. Foram escolhidas seis cidades brasileiras em diferentes latitudes, nas quais foi simulado um edifício de escritórios composto por aberturas com diferentes percentuais de obstrução da abóbada celeste. Analisou-se a iluminância útil (Useful Daylight Illuminances — UDI), por meio do software Daysim, e obteve-se como resultado a comprovação de que a inserção dos edifícios verticais nos centros urbanos —modelo usual nas cidades brasileiras— pode interferir na qualidade lumínica do ambiente interno

Noise metrics analysis in schools near airports: A Brazilian case study

This study compares metrics for environmental noise diagnosis in schools at airport vicinity. The goal is to analyze and identify the most suitable criteria for scaling aircraft noise impact over schools, during landing and take-off operations. A Brazilian case study is conducted, based on the noise mapping and sound level verification. The day-night average noise level (DNL) and the time above limit (TA) are investigated using acoustic simulation and noise mapping and in order to identify the critical receivers. Results of DNL and TA for two schools at airport surroundings show that the criteria adopted by the municipal and airport authorities to describe the airport noise are unsatisfactory and do not reflect the intermittent behavior of this type of noise. It was verified that individual receiver analysis, based on noise interruptions thought TA parameter is more suitable for evaluation of noise impact over schools at airport vicinity