A simulated case study of a library in Brazil to improve energy efficiency

The aim of this study is to quantify the energy savings of a library in the city of Foz do Iguaçu/Brazil, through simulations in EnergyPlus. Due to the great participation of air conditioning in the electric consumption of the building under study, the following proposals were studied: the exchange of the current split air conditioning units by a Variable Refrigerant Flow (VRF) system; the application of solar control films on the glasses; and both options together. The methodology followed these steps: firstly, it was simulated the current electricity consumption and the results were validated with real measures; secondly, the retrofitting measures were sized and implemented in the program and the energy savings were quantified; finally, an economic analysis was performed in order to determine the feasibility of the proposals. As a result, the VRF system showed an annual saving in air-conditioning of 42.08% related to the mini-split system. The annual electricity savings were 32.01, 2.14 and 32.80% for the VRF, solar control films, and both options together, respectively. The feasibility analysis of the VRF, considering financing and for a scenario consistent with the historical average growth of the electricity prices and inflation rate, showed that the use of a VRF instead of the splits units recovers the initial investment in 14 years. The application of solar control films proved to be economically unfeasible.