CO2

In 2022, a new law was passed by the Belgian federal government with the purpose to enhance the indoor air quality in public spaces in the aftermath of the COVID-19 pandemic. This new law, among other things, requires publicly accessible spaces to apply a CO2 meter and provides the option to have an IAQ label in place that informs the visitor about the indoor air quality of that space.

This study focuses on the impact of filtration efficiency level and airflow control, based on CO2, on indoor air quality described by particle concentration in an urban low energy consumption nursery school during an autumn and a winter period. Measurements of indoor and outdoor particle concentrations have been carried out by using three different filter efficiency configurations in the school equipped with a balanced ventilation system with heat recovery. The tested filters are respectively classed G4, M5 and F7 according to NF EN 779 (2012).

In many countries, the traditional method of ventilating dwellings involved natural ventilation, based on the operation of windows and high levels of infiltration through the building envelope, particularly through windows and window-wall joints. In Spain, in the middle of the last century, the use of vertical ventilation shafts in the wet rooms of dwellings became widespread, and it is currently the most common ventilation system in existing dwellings.

Efforts must be made to promote the use of efficient ventilation systems in buildings with the aim of reducing energy demand, as ventilation is a major source of energy loss. Nevertheless, the implementation of efficient ventilation systems is frequently constrained by regulations. It is therefore essential that governments and regulatory bodies facilitate and even encourage the use of appropriate solutions through the introduction of performance-based regulations. 

The COVID-19 pandemic increased the awareness and importance of infectious pathogens as contaminant in the indoor air, especially for non-residential buildings with a high occupational density like schools. During the COVID-19 pandemic air cleaning is often proposed as mitigation strategy for infectious risk in these types of buildings. However, indoor air quality (IAQ) in general comprises of a large range of possible contaminants and factors that can equally impact the health, comfort and well-being of occupants.

This paper presents the results of an Indoor Environment Quality (IEQ) monitoring study (including relative humidity, temperature and IAQ in terms of indoor CO₂) in naturally ventilated dwellings (mainly based on vertical shafts and infiltrations) and the analysis of the data obtained. The aim of the study is to identify patterns that relate occupants’ ventilation behaviour to outdoor temperature and to increase knowledge of occupant’s perceptions of IEQ. The results could be used to improve ventilation models and building regulations.

The relation between the concentration and particle size of the human breathing and the way in which these particles are dispersed in hospital indoor environments are studied in this research. Breathing thermal manikins are used to, experimentally, simulate a human person and its breathing activity. Two breathing thermal manikins are placed in a hospital room, simulating an infected patient, together with another standing manikin simulating a health worker.

Indoor air quality is a major area of concern in northern housing and could be influenced by ventilation. The required ventilation rate set by North American ventilation standards (ASHRAE 62.2, CSA-F326) is calculated on the basis of fixed floor area and number of bedrooms or people. The heat/energy recovery ventilators (HRV/ERV) on the market offer constant airflows and are selected to meet the required ventilation.

Indoor air quality (IAQ) control in educative centres, where students spend most of their time, is essential. The presence of high levels of contaminants can impact the academic performance of the students and, ultimately, their health. A study has been carried out to assess the IAQ of higher education classrooms with natural ventilation in order to quantify the exposure of the occupants to certain contaminants during the cold season. CO2, PM10, PM2.5, PM1.0, and volatile organic compounds (VOC) have been measured.

How accurately can reduced-order dynamic building energy simulation models (with Dymola simulation software) simulate the indoor climate (i.e., indoor air temperature, relative humidity and CO2-concentration) in common inhabited residential buildings? In order to address this question, high resolution measurement data of a zero-energy case study dwelling were gathered through a measurement campaign. A dynamic multi-zone modelling approach has been applied to have room-level indoor climate results.