Discussão das possibilidades de Retrofit energético no Casarão 2 segundo os critérios da INI-C e da EnerPHit Standard.

Abstract

Buildings were responsible for 50.5% of total electricity consumption in Brazil and the trend is for this consumption to increase over the years. This shows the importance of investing in legislation and techniques aimed at energy efficiency in buildings. The performance of retrofits is complex in many cases, especially in historic buildings, since the legislation for the preservation of historical heritage restricts the possibilities of changes in the envelope. Due to this difficulty, the present work aims to analyze the possibilities of energy retrofit in a historic building with level 1 listed, from the perspective of historical heritage, energy efficiency and economic viability, in the climatic context of southern Brazil (bioclimatic zone 2). This research can be classified as a case study of Casarão 2, using qualitative and quantitative techniques to define the quality of the energy retrofit. In the quantitative part, computer simulation was used to ascertain the energy efficiency of the real and modified model, from the perspective of INI-C and EnerPHit Standard. In this part, a budget and a simple payback for each retrofit were also made, to ascertain the viability of the models. In the qualitative part, the impact of each modification of the retrofits on the Casarão 2 envelope was evaluated. The real model obtained 67% of the hours occupied in thermal comfort to 80% of acceptability of the adaptive comfort of ASHRAE 55 (2010). Even using passive strategies to optimize the building, it was not possible to reach 90% of hours in thermal comfort, required by INI-C for the building to be fully ventilated naturally, being necessary to implement a hybrid climate system. With this system, Casarão 2 now has level “B”. Of all the models, the Model 45 - PTHP and 5cm of glass wool - came close to being viable in a historic building. This model reached level A of INI-C, the minimum criteria of EnerPHit Standard. Its modifications do not cause visual impacts on the building's facade and can be considered economically viable, depending on the useful life limits adopted by NBR 15575 (2013) for air conditioning systems. The results of this research showed the complex relationship between improving the energy efficiency of a historic building and maintaining its characteristics of historical relevance. Every retrofit changed the envelope of the historic building to some degree. The important thing in buildings listed on level 1 is that this change does not cause visual impacts or cause loss of historical material in the envelope. Although it is difficult for retrofit in a historic building to find a balance between energy efficiency, preservation of historic heritage and economic viability, this is not impossible. Model 45 showed this possibility, and further studies on this topic are needed to reach a more solid verdict.