Thermal comfort, energy efficiency and economic feasibility in social interest houses

Abstract

Minha Casa Minha Vida Program (PMCMV) contributed to reducing the housing deficit in Brazil. However, its replication characteristics link the inadequacy of housing envelopes to the local climate. The objective of this paper was to evaluate the effect of the adequation of the envelope of a SIH - Real Model (MReal) - to a Housing Prototype (PH), which incorporates guidelines from NBR 15220-3 and Amendment 1 of NBR 15575, regarding thermal comfort and energy efficiency, in addition to the economic feasibility of the modifications. Six procedures were established: (1) selection and characterization of cities in Bioclimatic Zone 8; (2) characterization of materials according to NBR 15220 and NBR 15575 standards; (3) proposition of parametric virtual models; (4) simulation of MReal and PHs; (5) analysis of thermal comfort and energy efficiency of the simulated models and (6) economic feasibility. In the simulation of 72 scenarios, the best performance was obtained by the PH2-20% prototype – ceramic block, roof tiles with PUR core, PVC lining and maxim-air windows with vertical shutters and 20% of usable ventilation area – in Colatina and Vitória, reducing the Cooling degree hours (CDH) by 4,970 and 5,511 °C.h, respectively. It effectively decreased electricity consumption and costs, around 65% (R$ 1,288.55/year) in Colatina and 63% (R$ 1,316.71/year) in Vitória. Changes were also economically viable, featuring attractive projects and Vreturn exceeding 13 thousand reais in 15 years and 20 thousand reais, in 30 years, with Payback less than three years for the two cities, demonstrating that simple changes provided significant improvement in SIH.