AVALIAÇÃO DO FLUXO DE CALOR EM COBERTURAS COM BARREIRAS RADIANTES

Abstract

The energy consumption in buildings is emphasised in national and international scenario, being influence for cooling systems. To reduce the cooling demand, strategies like radiant barriers and reflective insulation shown efficient. Laboratory measurements, in situ measurements and simulations can evaluate the performance of those strategies. The simulation method, the goal of this paper, has limitations since they are simplifications of physical phenomenal regarding the use of equations. Besides that, they are an important tool, since they allow obtaining results faster than laboratory and in situ measurements, and they can be validated comparing the simulation results with laboratory or in situ results. The goal of this paper is to evaluate how modelling in EnergyPlus influences the results of internal surfaces temperature, heat flux and thermal loads of radiant barriers and reflective insulation. To evaluate the influence of modelling, three different scenarios were adopted, using low emissivity materials, and comparing with two reference models with high emissivity materials, for three different cities, Curitiba, Rio de Janeiro and Santa Maria. In All three scenarios was possible to find heat flux reductions between 30 and 55%. The scenario 3, with radiant barriers and Energy Management System had the best’s results for all three cities, reducing 55% the heat flux and 20% the internal cooling loads.