Impact of ventilation type on indoor generated PM and VOC levels for different indoor activities

Abstract

Abstract Residential ventilation systems target in an energy efficient manner an indoor atmosphere fulfilling people’s desired comfort requirements with regard to CO2, temperature, and RH. However, the reach of an indoor atmosphere is not limited to comfort only. Ensuring a healthy indoor atmosphere reducing the risk of acute and chronic diseases caused by the inhaled air is also of importance. A number of elements contribute to indoor air pollution, such as: Volatile Organic Compounds (VOCs), infectious aerosols, and Particulate Matter (PM). These elements combined with the larger proportion of time spent indoors by humans put an emphasis on creating healthy spaces indoors. This investigation treats and discusses in-situ indoor measurements with the Renson Sense of PM1,2.5,4,10, and VOCs caused during the following activities: induction cooking of a typical European meal, vacuuming, and burning of regular and scented candles. All activities were carried out according to a fixed schedule. Both PM and VOC were measured in several rooms of a single, airtight dwelling in Belgium while the following ventilation options were considered: no ventilation, window ventilation, intensive ventilation via a cooker hood, Mechanical Extract Ventilation (MEV = natural supply, mechanical exhaust), and Mechanical Ventilation with Heat Recovery (MVHR = mechanical supply and exhaust). The exhaust flow rate of both MEV and MVHR was set identical to avoid the impact of different air exchange rates on building level. The following main findings were derived from the results. Particle diameters <1 µm (PM1) were dominantly present during all activities and for all considered ventilation options, possibly due to the sensor technology. The spread of cooking-related PM was confined to the floor where the activity took place, and a cooking hood was most effective in reducing PM, as could be expected. Furthermore, no ventilation exhibited logically the slowest decay of PM1, whereas this was most pronounced for window ventilation followed by an equal decay for MEV and MVHR. Burning scented candles led to higher PM levels compared to regular candles, while the PM peak was observed for both when extinguishing the candle. The spread of PM from burning candles was also restricted to the floor where the activity took place, window ventilation clearly reduced the spreading throughout the floor compared to the other ventilation options. Vacuuming activity created much lower PM levels compared to induction cooking and burning candles and therefore the spread of this PM throughout the dwelling was generally non-significant. Regarding VOC, the impact from induction cooking and burning candles was apparent in contrast to vacuuming for all considered ventilation conditions. Next to this, the spread of VOC throughout the building was more limited compared to PM.