Water use in collective student housing

Abstract

[EN] Today, there is limited information available about actual cold and hot water use in collective student housing. Furthermore, equally little is known about how this water use is distributed throughout the day and how it is divided over all end users (e.g. toilet, shower, sink). Although some water use profiles can be found in standards and literature, these profiles are often an overestimate of the buildings water use.The production of hot water accounts for a large proportion of the total energy used in collective student housing. Current installations are often overdimensioned because the hot water use is not correctly estimated. This leads to unjustifiably higher energy use and installation cost. Understanding hot water use is important, not only for better design of domestic hot water systems in the buildings mentioned above, in order to ensure comfort, but also for a more accurate assessment of the health risks of such systems. With an oversized system, there is more stagnation of water, resulting in Legionella problems. Having more correct tap profiles available in the design phase will inevitably lead to better understanding of the dimensioning and temperature distribution of the domestic hot water.In this paper, distribution system analyses and water monitoring has been carried out for six collective student accommodations, inhabited by 1756 students. The measurements show that the average water usage of a student is limited compared to numbers mentioned in standards, namely 40 litres of cold and 20 litres of hot water a day.