English

Control of HVAC systems may reduce congestion of the electricity grid on district level by shifting energy demand of buildings and increase the self-consumption of local photovoltaic energy. To achieve an optimal control of ventilation, occupant behaviour should be taken into account. To describe occupant behaviour, usually black box models are used and typically need large amounts of high quality training data. Alternatively, use of physical relations allows for a good predictive power requiring less training data.

The placement of mobile air cleaners (MACs) in classrooms was widely discussed between parents, teachers, and authorities in Germany during the peak of Corona infections in 2020 and 2021. Measurements of mobile air cleaner efficiencies in larger laboratory rooms indicated that there are substantial efficiency differences between test re-sults in a real room compared to results measured in a standardized 28m³ well-mixed clean test room according to a standard. The test method described here overcomes the multiple problems and uncertainties of aerosol particle decay tests.

Indoor Air quality (IAQ) of dwellings is the result of several sources and processes, and the impact of ventilation system is the one amongst many others. Definition and metrics of IAQ are several and we choose in this study to focus on airborne particle levels. Our question was: How the filtration of supply air impacts particle levels in indoor air?  

Within the ventilation principle of buildings, the outdoor air is considered as a source of fresh, "clean" air. However, as we all know, this is not always the case. Although the outdoor air quality in our cities already improved, the concentrations of certain pollutants, especially particulate matter and peak pollutions of ozone (and its precursors nitrogen oxides and volatile organic compounds), remain problematic.

Outdoor air is usually considered as a source of clean air in building ventilation principles. Although outdoor air quality has already improved in our cities, this principle may be challenged. Particulate matter remains especially problematic. This simulation study investigates the role that the mechanical ventilation system, with or without filtration, plays in the penetration of outdoor air pollutants, which may have adverse effects on indoor air quality and occupant health. Based on the Brussels PM2.5 pollutant data, several configurations were examined using the CONTAM software.

Airtight and highly insulated buildings are subjected to overheating risks, even in moderate climates, due to unforeseeable events like frequent heatwaves and power outages. Educational buildings share a major portion of building stocks and a large percentage of the energy is expended in maintaining thermal comfort in these buildings. Overheating risks in educational buildings can lead to heat-stress and negatively impact the health conditions and also cognitive performance of the occupants.

The use of the word “resilience” has increased significantly since 2010, however, there is a lack of understanding around 1) how thermal resilience is defined (where some definitions were offered only recently) and 2) what distinguishes it from typical overheating assessments. In addition to this, there is a lack of uptake in the remote monitoring industry (which uses low-cost solutions) when it comes to typical parameters used in thermal comfort studies and there is need to demonstrate how resilience performance can be reported going forward.

Urban settings change the microclimate around buildings and resulting thermal comfort inside.  This paper presents a method to consider microclimatic conditions, especially the effect of wind variations around the building, which impacts natural ventilation rates and indoor operative temperatures.

Current HVAC control systems assume occupant-related information, i.e., preferences, occupancy and behaviour. Furthermore, occupants often have limited control over the indoor environment in non-residential buildings. As a result, occupants are often dissatisfied with the indoor environmental quality (IEQ). This study works towards defining a novel occupant-centric control (OCC) framework which integrates occupants’ feedback regarding their satisfaction with the IEQ. This study collected both occupant satisfaction assessments via surveys and IEQ measurement data in various case studies.

In the frame of the project Flux50 smart ventilation, researchers and industrials aim at qualifying ventilation in mid-sized buildings through multidisciplinary consideration of sleep quality, user satisfaction, acoustic comfort, installation, maintenance, resilience and indoor air quality. As those factors may impact at different levels it is important to select a common metric for evaluation. Assessment of financial costs induced by the various categories will be used in that purpose.