TY - JOUR TI - Effects of airing behaviours on bedroom air pollutants during sleep AU - Liao, Chenxi AU - Fan, Xiaojun AU - Petrova Bivolarova, Mariya AU - Mainka, Anna AU - Sekhar, Chandra AU - Laverge, Jelle AU - Lan, Li AU - Akimoto, Mizuho AU - Wargocki, Pawel T2 - CLIMA 2022 conference AB - Higher ventilation rates were verified to have a positive impact on indoor air quality and therefore benefit sleep quality. However, how does ventilation influence bedroom air quality if the outdoor air quality is poor? Whilst ventilation helps to reduce indoor pollution it inadvertently brings outdoor pollution indoors, such as NO2, which is from vehicular emission. In this study, we collected the info of window and door status during sleep and measured carbon dioxide (CO2), nitrogen dioxide (NO2), volatile organic compounds (VOCs) and particulate matter (PM2.5 and PM10) among 38 bedrooms while occupants were sleeping during nights. Meanwhile, the air change rate (ACR) was calculated. The experiments were conducted in the heating season (September to December 2020) in the capital region of Denmark. The median values were 981.8 ppm (mean CO2 level during sleep), 0.6 h-1 (ACR), 3.4 µg·m−3 (NO2), 166.2 µg·m−3 (VOCs), 11.0 µg·m-3 (PM10) and 2.8 µg·m-3 (PM2.5). CO2 levels were positively correlated with VOCs levels, whereas negatively correlated with NO2 levels in bedrooms. ACR was also negatively correlated with VOCs. CO2 levels were significantly higher whereas NO2 levels were lower with both window and door closed compared to them with either window or door open. With higher ventilation rates, while occupants would be less exposed to indoor pollution of VOCs, they would be increasingly exposed to NO2. Future studies of bedroom ventilation and sleep quality should consider outdoor air quality. DA - 2022/05/13/ PY - 2022 DO - 10.34641/CLIMA.2022.128 DP - DOI.org (Datacite) SP - 2022: EP - CLIMA 2022 The 14th REHVA HVAC World Congress LA - en UR - https://proceedings.open.tudelft.nl/clima2022/article/view/128 Y2 - 2022/05/29/15:11:31 KW - BE:RELEVANT ER - TY - JOUR TI - A survey of bedroom ventilation types and the subjective sleep quality associated with them in Danish housing AU - Liao, Chenxi AU - Akimoto, Mizuho AU - Bivolarova, Mariya Petrova AU - Sekhar, Chandra AU - Laverge, Jelle AU - Fan, Xiaojun AU - Lan, Li AU - Wargocki, Pawel T2 - Science of The Total Environment AB - We performed a survey of the types of bedroom ventilation in Danish dwellings (January–February 2020) and the associated subjective sleep quality. Five hundred and seventeen people responded. Their median age was 33 years old and 55.4% of them were males. We used an online questionnaire and collected information on the type of bedroom ventilation, bedroom airing behaviour by the respondents, the bedroom environment, building surroundings and location, and sleep disturbance caused by stuffy air, noise, and the thermal environment. Subjective sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI); its median among respondents was >5 indicating reduced sleep quality. 35.4% of the bedrooms had mechanical, 24.6% exhaust, and 40.0% natural ventilation. Sleeping in a bedroom with mechanical ventilation tended to reduce sleep disturbance. The absence of mechanical ventilation and the presence of carpet in the bedroom were all associated with stuffy air causing sleep disturbance, which was the second most sleep disturbing factor. PSQI increased significantly with increased sleep disturbance. People who reported that their sleep was disturbed by stuffy air or “too warm” conditions opened windows frequently during the day or night, but no association was found between PSQI and bedroom airing behaviours. Our results are valid for the heating season and the survey would have to be repeated in the non-heating season to permit generalization of the findings. The results present associations and are qualitative, so field measurements are necessary to validate the present observations and provide further explanations. DA - 2021/12/01/ PY - 2021 DO - 10.1016/j.scitotenv.2021.149209 DP - ScienceDirect VL - 798 SP - 149209 J2 - Science of The Total Environment LA - en SN - 0048-9697 UR - https://www.sciencedirect.com/science/article/pii/S0048969721042820 Y2 - 2022/05/29/15:15:57 KW - BE:RELEVANT KW - Noise KW - Occupant behaviour KW - PSQI KW - Sleep disturbance KW - Stuffy air KW - Thermal comfort ER -