occupant behaviour

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.

Elderly people residing in nursing homes spend a vast majority of their times indoors and often in common recreation areas, to allow for socialization and interaction. Elderly people are a vulnerable age group. Hence, it is essential to provide them with good breathable air quality during these common activities and reduce cross contamination through ventilation. Prolonged exposures of elderly to contaminants may adversely affect their health, quality of life and increase medical expenditures due to frequent hospitalizations.

Computational predictions of buildings' indoor-environmental conditions and energy performance would presumably benefit from the inclusion of models that could reliably capture occupants' window operation behaviour. Frequently, models derived from empirical data have a black-box character. However, the utility of window operation models could be conceivably improved, if the model derivation process is preceded by specific hypotheses regarding the variables that are assumed to influence the frequency and timing of window operation actions.

Heatwaves are extreme events that will become more frequent and intense with climate change. Maintaining a comfortable and healthy indoor environment becomes crucial during these periods. The occupants are not just passive individuals who undergo the evolution of their environment. They can act to ensure their thermal comfort, in particular by opening or closing windows in summer.

The opening of windows can lead to high energy losses in wintertime, especially in nearly zero-energy buildings. But can reduce overheating significantly in summertime. Therefore, window use models have been created in the past to assess the energy use and thermal comfort in residential buildings. The models are mostly based on weather-variables. However, a recent study (Verbruggen, Janssens, et al. 2018) indicated that these models were not able to accurately predict the window use in wintertime. For that reason, an occupancy and activity based model was developed.

Occupants control indoor environments to meet their individual needs for comfort. The control of window is the most common natural ventilation method influencing indoor environment as well as the energy use of the buildings to maintain a suitable environment. Therefore a better understanding of window control behaviour of the occupants has significant implication to enhance occupant comfort with minimal energy consumption. The objective of this study was to identify an appropriate algorithm and variables to develop a predictive model for window control.

Indoor air quality and thermal comfort was measured in 14 three-bedroom, semi-detached, cavity wall naturally-ventilated homes during the winter following an energy efficient retrofit. As part of the energy retrofit, homes received new windows and doors, an upgraded heating system, attic insulation, and wall vents, as well as pumped beaded wall insulation into three external walls.

It has already been proven that a large portion of the energy consumption gap between simulations and reality is due to the occupant behaviour in buildings. The improving airtightness of buildings makes that Indoor Air Quality (IAQ) can no longer rely on air renewal through infiltrations, bringing the need of ventilation systems. Within this frame, an ongoing dissertation focuses on the relationship between occupancy behaviour and ventilation systems in low energy buildings.

The proceedings of the seventh AIVC Conference contain 16 papers and 5 posters as follows: Requirements for adequate and user-acceptable ventilation installations in dwellings; Ventilation air infiltration and building occupant behaviour; A preliminary study of window opening in 18 low energy houses; Occupants' influence on air change in dwellings; The influence of occupant behaviour on indoor air quality - a case study; Ventilation and occupant behaviour in two apartment buildings; Inhabitant behaviour with regard to mechanical ventilation in France; Ventilation heating system of small hou

This paper presents an ideal and worst case scenario approach for occupancy modelling in early design stages which can be used in building simulation. It defines the range of impact that occupant behaviour can have on comfort and energy performance in buildings, and can thus contribute to the decision making of architectural projects in early design stages.