Modelling sanitary demands for occupant loads in shopping centres of Hong Kong

Abstract

This paper presents a quantitative mathematical model of sanitary demands from occupants in shopping complexes. In-situ measurements and interview surveys with occupants were conducted in typical local shopping malls in order to determine the model parameters for their visiting patterns, load patterns, demand patterns and their preferred or acceptable duration for waiting and using water closets (WCs). The model is used to assess the probable acceptance of sanitary facilities towards the acceptable amount of time for waiting at a typical female washroom designed for an occupant load of 600 occupants in a shopping mall. The results showed that the current sanitary provisions for female washrooms in local shopping malls could meet occupants’ minimum expectation, while with an additional 33% of WC, the sanitary would fully satisfy ‘all’ occupants in terms of amount of time for waiting. Practical applications: This paper presents a quantitative mathematical model of sanitary demands from a group of building occupants. This model is applied to evaluate the performance of sanitary provisions at typical female washrooms in Hong Kong shopping malls and to quantify the provisions required to achieve the most acceptable amount of time for waiting to their users.

A Review of Demand Models for Water Systems in Buildings including a Bayesian Approach

“…can be included either through various approximations of parametric distribution functions, surveyed frequency distributions, or further physical relationships. The queuing models by Goncalves and Alves da Graca [25] and Mui and Wong [45] for sanitary appliances in congested use and a fuzzy algorithm by Oliverira et al [46] …”

“…can be included either through various approximations of parametric distribution functions, surveyed frequency distributions, or further physical relationships. The queuing models by Goncalves and Alves da Graca [25] and Mui and Wong [45] for sanitary appliances in congested use and a fuzzy algorithm by Oliverira et al [46] for demand start time and duration calculations are a few good examples. For simulations of the simultaneous demands, a time-series is subdivided into a number of time partitions τi, i = 1, 2, 3, …, with a number of demands N of appliances j = 1, 2, 3, …; and each demand has a time variant demand qj(t) for each operation and a uniformly distributed demand start time tj in τi [36].…”