English

Long-term continuous measurements of temperature, humidity and CO₂ concentrations were conducted in offices in three buildings of over 3,000 m² and three non-specified buildings of less than 3,000 m². These measurements were carried out to investigate the effect of the hygrothermal environment in winter and summer, with a particular focus on the impact of humidity in winter and the hot and humid environment when air conditioning is turned off in summer, on microbial contamination.

In recent years, population exposure to air pollution has been a major concern. Indoor air quality (IAQ) is mainly monitored with CO2-concentration-based indicators. High levels of CO2-concentration are avoided in buildings when airing by the windows is done and/or when air exchange rate of the existing ventilation is regulated, based on a CO2-level-information. However, as contributing to maintain low CO2-concentration-levels indoors, the increase of outdoor air intake is associated with a more or less important introduction of outdoor air pollutants in the building.

In this work we investigate the bidirectional filtration efficiencies of respirators, such as FFP2 masks and medical masks, under cyclic breathing and different fits. We developed a test bench, which consists of a test chamber with an artificial head, and which is connected to a specially developed artificial breathing function. The exhalation filtration performance of masks can be evaluated by exhaling particle-laden air into the test chamber. Similarly, the inhalation filtration performance can be evaluated by inhalation of particle-laden air from the test chamber.

This paper presents a comprehensive evaluation of Relative Humidity-Controlled Mechanical Extract Ventilation (RH-MEV) systems installed in multi-family social housing buildings, focusing on the assessment of in-situ aging and the impact of maintenance on the performance of the system. Building upon the Performance 2 project conducted from 2020 to 2024, which evaluated the durability and performance of RH-MEV systems over a 15-year period, this study delves deeper into the longevity and maintenance aspects of these systems.

Ensuring acceptable indoor air quality (IAQ) is critical for managing built environments. This is done by ventilating spaces with outdoor air to keep indoor pollutants like CO2, humidity, particulate matter, and VOCs within healthy levels. The effectiveness of ventilation strategies depends on factors like occupancy, pollutant types, and air terminal devices, which can be influenced by outdoor air quality, especially in urban areas with particulate matter and NOx. Ventilation devices can operate with constant airflow or adjust based on occupancy.

This study investigates the performance of Temporary Isolation Rooms (TIRs) in controlling airborne transmission of aerosols. The study utilized a full-scale experimental chamber with various airflow rates of Fan Filter Units (FFUs) and Air Changes per Hour (ACH). Aerosol removal efficiency and penetration coefficients were evaluated using Di-Ethyl-Hexyl-Sebacate (DEHS) particles and optical particle counters. Results showed that TIR performance varies significantly with aerosol diameters and FFU airflow rates.

Ventilation impacts the quality of the indoor environment. Indoor air quality (IAQ) contributes to the overall personal exposure of occupants of a building to certain pollutants and is therefore an important environmental determinant of health. Research shows that European citizens spend on average 90% of their time indoors. The Flemish government, and more specifically the Flemish Department of Environment & Spatial Development, has been conducting research on IAQ in homes and schools to inform and develop policy since 2007.

Increasing attention is being paid to radon concentrations in the assessment of indoor climatic comfort. Radon is a naturally occurring radioactive element that, under unfavourable circumstances, accumulates in excess in a building. Elevated concentrations of it can adversely affect the health of building occupants, resulting in increased interest in this element.

Many children between 1 and 3 years of age spend a fraction of their time in kindergartens. Poor indoor air quality, IAQ, could negatively affect children’s health, particularly respiratory health, attendance, and academic achievement.

In recent times, society has become increasingly aware of potential health problems associated with indoor environments. This is particularly important when considering young children, whose immune systems are not fully developed. Additionally, indoor air quality is influenced by outdoor air quality, which is often poor in many areas, especially in urbanized areas. This article presents the results of research on selected environmental comfort parameters conducted in preschool classrooms located near busy roads.