Balanced ventilation - energy efficient and healthy

When making homes more sustainable, the emphasis is on scaling up to achieve the climate and energy objectives. Little attention is paid to air quality in homes, despite the fact that an estimated 98% of the Dutch homes do not meet the WHO's 2021 annual guideline value for PM2.5. Tackling sustainability and the indoor environment hand in hand is therefore important. Airtight homes with balanced ventilation and effective range hoods offer the opportunity to significantly improve the air quality for residents in the homes, by reducing both particulate matter from indoor and outdoor sources. This possibility is currently not fully utilized. Most systems use coarse filters, while better indoor air quality can be achieved with a better filter class. The research question in this article is: What influence do ventilation systems, airtightness and effective range hoods and users have on the particulate matter concentration in the indoor air and, in particular, what is the effect of improved filtering? To answer this question, simulations were carried out with a ventilation model that included the effect of the type of ventilation system, cooking extraction, air tightness and window use. The effect of open windows was modelled with wind pressure coefficients and turbulent exchange. 
The simulations show that good cooking extraction in combination with better filtering of the ventilation air in the mechanical supply can significantly reduce exposure to particulate matter in homes, even when windows are open in the bedrooms for a large part of the year. This is mainly due to the much lower exposure in the living room. 
The simulated PM2.5 exposure in for both homes with supply via grilles and for homes with balanced ventilation with standard filters did not meet the WHO annual guideline value. Balanced ventilation with F7 particulate matter filters (ePM1 55%) resulted in a exposure below the WHO annual guideline value. Because the simulations assume that windows are open for cooling during part of the year, the use of even better filters only has a limited effect. In homes with active cooling, there is clear added value to using better filters than F7 quality, because then windows can remain closed.