Environment and health in children day care centre analysis and simulation of ventilation

Abstract

The need for studies on the relation between buildings physical characteristics and the indoor environment in children day care centres (CDCC) led an interdisciplinary team of researchers to develop the project ENVIRH, funded by the Portuguese Foundation for Science and Technology (FCT). The project team proposed to study the physical characteristics of the buildings, their indoor air quality and children's health. Physical modelling of ventilation is strongly dependent on the characteristics of the building and the precise evaluation of such characteristics is a complex and a time consuming work. As part of this project, a CDCC was selected in order to measure the envelope air permeability, the flow rate of mechanical ventilation systems and indoor and outdoor temperature. The effect of the wind on the envelope was estimated through the pressure coefficients and meteorological data was collected. This data was then used to perform a computational study of ventilation (using CONTAM model) the obtained results being validated against direct measurements of ventilation flow rate carried out with tracer gas techniques (short term measurements with CO2 tracer gas and medium term measurements with PFT method). After validation, this model is used to predict the ventilation rates under a range of weather conditions in order to perform a sensitivity analysis of the main parameters that affect ventilation. The purpose of this assessment was to find the best practices to improve natural ventilation avoiding impairing the indoor comfort. The purpose of this paper is to present and discuss the results obtained in this study.