The challenges on operating a zero net energy building facing global warming conditions

This study proposes a methodology to evaluate the energy performance of existing Zero Energy Buildings and to prospect retrofit strategies in a Savannah climate, concerning the A2 scenario of emissions from the Fourth Report of the Intergovernmental Panel on Climate Change. The selected building to study is recognized for its high energy performance, named Centro SEBRAE de Sustentabilidade (CSS). Two efficient measures were considered: (i) improvement in the air conditioning system coefficient of performance (COP) and (ii) in the energy efficiency of the photovoltaic plates of generation on-site. The methodology is grounded in the potential bioclimatic concept and the employed steps applied were: preparation of climate archives in the 2020, 2050 and 2080 time-slices; calibration of the computational model; evaluation of the retrofit strategies on its energy consumption efficiency through computer simulation. Considering the CSS has already attended mostly the bioclimatic strategies for the local climate and has high efficiency measures in its systems, the retrofit focused the air conditioning and PV system. The isolated retrofit of the air conditioning system was unable to guarantees the NZEB condition despite providing an adequate level of energy efficiency until 2080. The retrofit of the PV system was the only one that provides the NZEB condition for climate change scenarios. The contribution of this paper is to provide a guide to be used in NZEBs, with measures of optimization that provide high potential bioclimatic face to the local where it is built, making it possible to maintain this condition in scenarios of global warming.