Energy savings and exposure to VOCs of different household sizes with a smart ventilation system

Assessment methods to assess smart ventilation, in most countries focus only on comfort as criteria for the indoor air quality (IAQ), (Guyot et al., 2019). This is an issue as in doing so, pollutants that are known to cause harm to the human health are not taken into consideration while the exposure to VOCs will be elevated if the smart ventilation system lowers the ventilation flowrates to save energy (De Jonge and Laverge, 2021). This research addresses the question what the impact of changing family sizes would be on the individual exposure to unhealthy pollutants for a smart ventilation system that only uses comfort related parameters to control the ventilation system. By introducing sources of Volatile Organic Compounds (VOCs) into a Modelica building energy and IAQ model of a typical Belgian apartment the occupant-dependent (CO2 and RH) smart ventilation can be assessed for non-occupant dependent pollutants (VOCs). For a given smart ventilation system, ten different households, with varying sizes and occupants are simulated. 
The results show that the presence of other family members influences the exposure to VOCs of an individual. For the ten cases, the minimum DALY count is 14.75yr and maximum is 17.72yr. They also show that the energy use of the building can be quite different although the only changing parameter in the simulation are the occupants. For the ten cases, the minimum energy use is 731kwh and maximum is 1319kwh. 
When designing a simulation-based assessment framework for residential ventilation, the occupant’s behavior will always be an unknown factor to consider. The results indicate that in developing a simulations-based assessment framework, it will be best to not assume just one household as in doing so, the system performance for is not properly checked with regards to health and energy use during the lifetime of the system and the expected variation in household types and sizes. The results in this paper confirm the necessity of a stochastic approach for assessing a smart ventilation system based on health-related pollutants (VOCs).