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Today's common demand controlled ventilation systems lower the ventilation airflow rate based on real-time CO 2 and H 2 O measurements. Both ventilation system design and the Belgian assessment method for such systems, based on Monte-Carlo simulations, only consider these two comfort parameters. The health aspect of indoor air quality is thereby overlooked. A first step towards adding this aspect is the addition of Volatile Organic Compounds (VOC). As part of this research, eight different methods to model VOC emission and behavior in the airflow simulation software CONTAM are discussed: two methods to model event-based emissions, five methods to model continuous VOC emissions and one additional method to model sorption behavior. The overview illustrates the lack of an adequate, ready-to-use method that can be used to update the simulation based assessment method. Two methods (.CVF and TCP/IP) hold the potential to be used for this purpose but need to be further investigated.

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Indoor Air Quality (IAQ) is a complex issue. In a typical indoor environment, a large number of contaminants is present in the indoor air of varying nature and sources. Contaminants can be chemical (e.g., volatile organic compounds), biological (e.g., airborne viruses) or physical (e.g., airborne particles). The way people interact or react to the presence of some of these contaminants is another complex issue. This interaction between people and the indoor air can be classified into two categories: the way people perceive the indoor

The performance assessment of ventilation systems often focusses only on CO2 and humidity levels. The indoor Volatile Organic Compounds (VOC) emissions of building materials or other products is thereby overlooked. The new generation of ventilation systems, Demand Controlled Ventilation (DCV), are systems that do not supply the nominal airflow continuously but are controlled by CO2 or humidity sensors in order to save energy. This poses potential problems for exposure to VOCs. In this study, a dynamic VOC model, which takes into account changing temperature and humidity that was derived from literature, is implemented in a CONTAM model of the Belgian reference apartment. The impact of a DCV system on the indoor VOC levels is investigated. Results show that the use of a dynamic model is necessary compared to the previously used approximation of a constant emission. Furthermore, on a system level, the influence of the ventilation system control on the indoor VOC levels shows. The overall VOC concentration in the different rooms will be higher because of lowered ventilation rates. Especially in rooms that are often unoccupied during the day, the accumulation of VOCs shows. In the development of DCV system controls, the aspect of VOC exposure should not be overlooked to be able to benefit from both the energy savings and improved Indoor Air Quality (IAQ).