Navegando por Autor "Sattler, Miguel Aloysio"

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An experimental study on the use of earth-air heat exchangers (EAHE)
(2014) Vaz, Joaquim; Sattler, Miguel Aloysio; Brum, Ruth da Silva; Santos, Elizaldo Domingues dos; Isoldi, Liércio André
The thermal potential of Earth-Air Heat Exchangers (EAHE) is experimentally investigated for a placementin Viamão, city located in the south of Brazil. Three independent ducts are buried in the soil, ducts A and B are installed at a depth of 1.60 m and 0.60 m apart, while duct C is installed at a depth of 0.50 m. Thethermal conditions of one build named Casa Ventura are improved with the EAHE. The temperatures forthe soil, external air and in buried ducts in several positions are acquired along one year (2007). The mainpurpose here is the achievement of the transient behavior of temperature fields for the external air, soiland buried ducts and the best periods of time for employment of device. Results showed that the monthsof May and February were the best for heating and cooling the air used in Casa Ventura, respectively.Moreover, it was developed a complete database about the transient temperatures of the soil, externalair and inside the building.
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Analysis of the thermal behaviour of a low cost, single-family, more sustainable house in Porto Alegre, Brazil
(2008) Grigoletti, Giane de Campos; Sattler, Miguel Aloysio; Morello, Alessandro
Efforts have been made in Brazil to improve the thermal performance of low-cost buildings. Since 1997 studies on low-cost housing have been developed by Nu´ cleo Orientado para a Inovac¸a˜o da Edificac¸a˜o, the construction sector of the Engineering College of the Rio Grande do Sul University, Brazil. In 2000 a prototype of a low-cost house was built on the university campus. This prototype has undergone several evaluations in an attempt to assess its thermal and environmental performance, like: energy consumption, rainwater harvesting, use of sustainably managed wood for window frames and doors, besides a detailed accounting of overall costs. The thermal performance of the house was monitored, by recording outdoor and indoor air temperatures and relative humidity, over the period of whole year. A brief appraisal of such results, as well as the annual heating and cooling degree-hours are presented. Daily swings in outdoor are a common climatic event in Porto Alegre and the building response to daily temperature swings, greater than 10 K, and hot and cold spells are presented. The results show that the thermal performance of the prototype is fairly satisfactory, considering the limitations of a low-cost house, when artificial heating and cooling is not affordable
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Experimental and numerical analysis of an earth-air heat exchanger
(2011) Vaz, Joaquim; Sattler, Miguel Aloysio; Santos, Elizaldo Domingues dos; Isoldi, Liércio André
The need to develop new technologies that allow the use of sustainable alternative sources of energy is increasingly evident. Thus, this work presents an experimental and numerical study of earth–air heat exchangers, which are used to reduce consumption of conventional energy for heating and cooling of built environments through the use of thermal energy contained in the soil. The experiment was conducted in southern Brazil in the city of Viamão, and its results were used to validate the computational modeling of heat exchangers. In the present work, the variation of air temperature inside the ducts, to an annual cycle, was investigated. The numerical solution of the conservation equations of the problem is performed with a commercial code (FLUENT) which is based on the Finite Volume Method (FVM). Turbulence is tackled with the Reynolds Stress Model (RSM). The transient temperature fields predicted numerically was compared with the experimental ones, the highest difference found was lower than 15%. The results showed the validity and effectiveness of the employed computational model, enabling its use for future researches and projects developments about earth–air heat exchangers.