Author(s)

MYRIAM LOPES, JOHNNY REIS, ANA P. FERNANDES, DIOGO LOPES, RÚBEN LOURENÇO, TERESA NUNES, CARLOS H. G. FARIA, CARLOS BORREGO, ANA I. MIRANDA

Abstract

People spend about 90% of their time in indoor environments without really knowing about the quality of the air in these spaces. This lack of knowledge about the indoor air quality and the exposure time can aggravate the health conditions of the individuals in the indoor spaces of houses. The aim of this study was to study the feasibility of using low-cost sensors to quantify and to identify the main causes of poor indoor air quality. For this purpose, three houses with different locations were chosen, either regarding the surrounding environment or the behaviour of residents. Micro sensors for the main indoor air quality pollutants (CO, CO₂, PM₁₀, PM_2.5, NO₂ and Ox) were selected to build a sensor box. Bedrooms and living rooms were monitored for approximately seven months, from September 2019 to March 2020. Several associations between pollutants concentrations and occupant’s activity patterns or outdoor conditions were identified. Results showed that pollutants present in indoor air may also vary according to the season and their concentrations may also vary with outdoor air quality conditions. Results also showed that the determinants of indoor air concentrations varied considerably among different types of pollutants. The geographic location and surrounding environment of the house, resident’s behaviour and time-activity (space heating, ventilation or cooking) can change pollutants concentrations and therefore indoor air quality.

Keywords

indoor air quality, micro sensors, air quality monitoring, smart homes