User preferences and water use savings owing to washbasin taps retrofit: a case study of the DECivil building of the University of Aveiro

Abstract

During the last decades, achieving water efficiency in buildings has increasingly become an important challenge in the scope of sustainability. Water consumption is directly related to individual conduct. Despite the various technological improvements in fixtures and appliances, their performance will be influenced by human preferences and behavior. As a result, the potential for effective water consumption saving is influenced by behavior change as well as water-efficient fixtures and appliances. This work evaluates the impact of user preferences and behavior change on the water-efficient performance of tap aerators in a case study building: the Department of Civil Engineering building of the University of Aveiro, Portugal. Four aerators with different discharge reductions and types were installed in the toilet's washbasins and the user's preferences and behavior change measured through direct and online questionnaires. It was observed that the effective water consumption reduction (15 to 49%) was less than the discharge reduction (30 to 70%), confirming that user factors influence water savings. Water use reductions in the tested range (2.0 to 6.7 l/min) also varied according to gender, with male users using less water than their female counterparts. It was noted that an awareness of sustainability values prevailed amongst the users when confronted with the choice between comfort and water efficiency, although differences were observed in the user preferences regarding the various aerators. When confronted with the information that the lower discharge aerator would contribute to a reduction of about 70% on the water discharge, 25% of the users agreed with its use, even if it resulted in a certain degree of dissatisfaction. In comparison, only 8% of the users completely disagreed with its installation. On average, the water consumption reduction was 46% smaller than the discharge reduction achievable with the aerator alone. This further confirms the user factors inform the degree of water savings that is achievable from water-efficient fittings and fixtures.

Beyond the flow rate: the importance of thermal range, flow intensity, and distribution for water-efficient showers

“…They concluded that satisfaction and usage water flow have a spurious correlation relationship, and this was also confirmed by this study. But the findings contradict Meireles et al (2018) study of taps, which found that female participants were more conservative in estimating their use duration and therefore water use compared with the male participants. This study did not find such gender correlations; instead, the shower durations varied more in line with the use, and effectiveness of the showerheads to meet the participant's requirements and levels of experiential satisfaction, relative to the purpose of the shower.…”

The influence of different water efficiency ratings of taps and mixers on energy and water consumption in buildings

“…The obtained results allowed them to determine the trends in cold-and hot-water consumption, as well as to estimate the energy required for water heating. Meireles 105 Levels 5 and 6 (CHS) et al [45] carried out a study on water savings for washbasin mixers equipped with different aerators. The authors also analysed how the preferences of users influence the level of water consumption savings and whether the application of water-saving faucets is fully utilized.…”

Greenhouse Gas Emissions and Energy Savings Owing to Water Appliances Retrofit

“…The water reducers efficiency will depend on the users' behaviour. Meireles et al [6] found that reduction in water consumption associated to the installation of water reducers in the DECivil building was lower than the reduction of water discharge due to user's behaviour adjustment to the lower water discharge (no change in the duration of operation per push was introduced).…”