Assessment of water end-uses in four office buildings located in Florianópolis

Abstract

This paper presents the methodology used to estimate the water end-uses in four office buildings located in Florianópolis, southern Brazil. The estimates were performed considering the water consumption habits, which were obtained by interviewing the occupants of the buildings. The answers given by the occupants indicate the daily amount of time and frequency of use of water for four specific consumptions: toilet flushing, taps, cleaning and other uses. Water flow rates from taps and bowl-and-tank toilets were obtained through local measurements; for toilets with wall flushing valves, the water flow rate was obtained from a the NBR 5626 standard. From these data, monthly water consumption in the buildings and water end-uses were calculated. The estimated water consumptions were compared with the measured consumptions for a period of two years. In order to eliminate the difference between the estimated and the measured consumption, a sensitivity analysis was performed. Consumption habits were varied to find out which specific consumption has the most important influence on the estimated water consumption for each building. An analysis on the influence of the size of the sample of occupants interviewed was also performed. Toilet flushing was the most important specific consumption in all four buildings, indicating that there is a great potential for potable water savings in those buildings.