Energy efficiency of dwellings' envelope in Rio de Janeiro: the impact of openings on INI-R

o impacto das esquadrias pela INI-R

Abstract

Within the Brazilian National Policy for Saving and Rational Use of Energy, Inmetro's Normative Instruction for the Classification of Energy Efficiency in Residential Buildings (INI-R) is the legal instrument for obtaining the rating the energy efficiency of dwellings. This paper focuses on Rio de Janeiro city  and aims to verify how some architectural variables used in the evaluation process can be more decisive than others for classification of dwellings about their efficiency in terms of electric energy consumption. The influence of openings was specifically investigated, as they are easily replaceable architectural elements in the search for a better classification, unlike the constituent materials of the walls, for example. The work continues a previous investigation, done in a similar way, which used the prescriptive method of the Regulation of Technical Quality Level Energy Efficiency of Residential Buildings (RTQ-R). The current study used the simplified method of INI-R, and both tested the influence of openings on the envelope evaluation results of a hypothetical housing unit, in a multifamily residential building, tested in four different orientations. The parameters defined for the investigation of the frames were their opening percentage (45% or 90%) and the existence or not of louvers. The results indicate shading by louvers as the most significant parameter of influence. The opening percentage may or may not provide gains when changed, although these are more discreet and, in the current regulation, INI-R, it no longer means a change in classification, unlike what happened in the RTQ-R. The product of this analysis can be adopted as a tool for decision-making in housing renovations and as input for new home projects.