Influência das séries históricas de dados pluviométricos no dimensionamento do sistema predial de aproveitamento de água pluvial de uma unidade de ensino

Abstract

The constant increase in demand for drinking water and water crises around the world has been the reason for seeking alternatives that minimize their environmental and social impacts. The rainwater harvesting systems, has stood out due to the direct and indirect benefits generated with its implementation. However, the economic aspect of the system is still of great importance in investor decision making. The high costs often derive from the rainwater storage subsystem, which represents a large percentage of the system's initial investment, and it is important to use accurate data in its sizing. Among the main elements used to find the volume of the rainwater tank is precipitation data obtained from historical series. Thus, this work analyzes the influence of the duration of different historical series of precipitation on the economic feasibility of rainwater harvesting system to be implemented in the building attached to the Federal Institute of Goiás - Câmpus Goiânia. Precipitation periods of 5, 10, 20 and 50 years were considered in monthly and daily data in which the ideal reservoirs were dimensioned with Neptune Computational Program V4.0. The economic evaluation performed through the calculation of consumption indicators, demonstrated the financial unfeasibility of the implementation of rainwater harvesting system in the building. By analyzing the results for each series of precipitation, it was possible to observe that the storage volume increased as the precipitation period increased, thus generating greater saving of drinking water and consequently greater economic attractiveness. When checking the use of daily and monthly data, it is noted that the use of daily data results in lower reserve volumes but with greater economic potential. Even with its economic unfeasibility, the implementation of the system should not be discarded, since it presents considerable contributions in the sustainable context. Thus, the ideal configuration of the rainwater harvesting system would have a lower reservoir of 11500 liters resulting in a saving of 66.78% of non-potable consumption in the building.