DESEMPENHO TÉRMICO DE ÁTICOS COM ISOLAMENTO TÉRMICO REFLEXIVO: ESTUDO EM UMA BANCADA EXPERIMENTAL
DOI:
https://doi.org/10.46421/entac.v17i1.1362Palavras-chave:
Roof, Heat flux, Thermal resistanceResumo
One of the major worries arisen in the past years concerns the quantity of energy spent in order to provide thermal comfort in buildings, since a large part of this energy results from the heat transference through the coverage. Encouraging the reduction of thermal gain through this surface is one of the ways to decrease the expenses with energy and to provide thermal comfort. This research aims to evaluate the thermal performance of attics with and without reflective thermal insulation in the summer and winter by experimental measurements. To this end, a testing workbench was built and four samples of coverage were evaluated. All samples contained fiber cement tiles and concrete slab, one of which was used as the reference, two present reflective thermal insulation and the last is formed by white tiles. Results showed that the use of reflective thermal insulation increased the attic thermal resistance in both seasons. In the descendant heat flow (summer), the attic thermal resistance was higher than in the ascendant flow (winter). Regarding the white tiles effect, there was a decrease in the superficial temperatures and the diurnal heat transference in both seasons.
Referências
ASADI, S.; HASSAN, M.; BEHESHTI, A. Development and validation of a simpleestimating tool to predict heating and cooling energy demand for attics ofresidential buildings. Energy and Buildings, v. 54, p. 12 21, 2012.
ASADI, S.; HASSAN, M. M. Evaluation of the thermal performance of a roof-mountedradiant barrier in residential buildings: Experimental study. Journal of Building Physics,v. 38, n. 1, p. 66 80, 2014.
BELUSKO, M.; BRUNO, F.; SAMAN, W. Investigation of the thermal resistance of timberattic spaces with reflective foil and bulk insulation, heat flow up. Applied Energy, v.88, n. 1, p. 127 137, 2011.
CHANG, P. C.; CHIANG, C. M.; LAI, C. M. Development and preliminary evaluation ofdouble roof prototypes incorporating RBS (radiant barrier system). Energy andBuildings, v. 40, n. 2, p. 140 147, 2008.
CRAVEN, C.; GARBER-SLAGHT, R. Reflective Insulation in Cold Climates. Fairbanks,Alaska, USA, 2011.
insulation: Field tests under hot climatic conditions. Journal of Building Physics, v. 36,n. 3, p. 229 246, 2013.
DESJARLAIS, A. O. Radiant Barrier Fact Sheet. 2010.
DIMOUDI, A.; LYKOUDIS, S.; ANDROUTSOPOULOS, A. Thermal performance of aninnovative roof component. Renewable Energy, v. 31, n. 14, p. 2257 2271, 2006.
GUO, W. et al. Study on energy saving effect of heat-reflective insulation coating onenvelopes in the hot summer and cold winter zone. Energy and Buildings, v. 50, p.196 203, 2012.
GÜTHS, S. et al. Um transdutor de fluxo de calor a gradiente tangencial. XI CongressoBrasileiro em Engenharia Mecânica. Belo Horizonte, Minas Gerais: Anais do XICOBEM, 1995HAUSER, G. et al. Experimental and numerical investigations for comparing thethermal performance of infrared reflecting insulation and of mineral wool. Energyand Buildings, v. 58, p. 131 140, 2013.
International Organization for Standardization - ISO: 9869 Thermal insulationBuilding elements In-situ measurement of thermal resistance and thermaltransmittance Part 1: Heat flow meter method, 2014.
MEDINA, M. A comprehensive review of radiant barrier research including laboratoryand field experiments. ASHRAE Transactions, , 2012.
MEDINA, M. A. Effects of shingle absorptivity, radiant barrier emissivity, atticventilation flowrate, and roof slope on the performance of radiant barriers.
International Journal of Energy Research, v. 24, n. 8, p. 665 678, 2000a.
MEDINA, M. A. On the performance of radiant barriers in combination with differentattic insulation levels. Energy and Buildings, v. 33, n. 1, p. 31 40, 2000b.
MEDINA, M. A.; YOUNG, C. B. Evaluating the Sensitivity of Attic Radiant BarrierPerformance to Climate Parameters. Journal of Energy Engineering, v. 134, n. 1, p. 25, 2008.
MICHELS, C.; LAMBERTS, R.; GÜTHS, S. Evaluation of heat flux reduction provided bythe use of radiant barriers in clay tile roofs. Energy and Buildings, v. 40, n. 4, p. 445451, 2008a.
MICHELS, C.; LAMBERTS, R.; GÜTHS, S. Theoretical/experimental comparison of heatflux reduction in roofs achieved through the use of reflective thermal insulators.
Energy and Buildings, v. 40, n. 4, p. 438 444, 2008b.
MIRANVILLE, F. et al. A combined approach for determining the thermalperformance of radiant barriers under field conditions. Solar Energy, v. 82, n. 5, p.399 410, 2008.
MIRANVILLE, F. et al. Evaluation of the thermal resistance of a roof-mounted multireflectiveradiant barrier for tropical and humid conditions: Experimental study fromfield measurements. Energy and Buildings, v. 48, p. 79 90, 2012.
SABER, H. H. Investigation of thermal performance of reflective insulations for differentapplications. Building and Environment, v. 52, p. 32 44, 2012.
SABER, H. H. Practical correlations for thermal resistance of horizontal enclosedairspaces with upward heat flow for building applications. Building and Environment,v. 61, p. 169 187, 2013.
SABER, H. H. Practical correlation for thermal resistance of horizontal enclosedairspaces with downward heat flow for building applications. Building andEnvironment, v. 37 (4), p. 403 435, 2014a.
SABER, H. H. Practical correlation for thermal resistance of horizontal enclosedairspaces with downward heat flow for building applications. Journal of BuildingPhysics, v. 37 (4), p. 403 435, 2014b.
WINIARSKI, D. W. -steady-state model of attic heat transfer withradiant barriers. Energy and Buildings, v. 24, n. 3, p. 183 194, 1996.
