Analysis of Ventilation Efficiency as Simultaneous Control of Radon and Carbon Dioxide Levels in Indoor Air Applying Transient Modelling.

Autor: Dovjak M; Buildings and Constructional Complexes, Faculty of Civil and Geodetic Engineering, University of Ljubljana, 1000 Ljubljana, Slovenia., Vene O; Buildings and Constructional Complexes, Faculty of Civil and Geodetic Engineering, University of Ljubljana, 1000 Ljubljana, Slovenia., Vaupotič J; Department of Environmental Sciences, Jožef Stefan Institute, 1000 Ljubljana, Slovenia.
Jazyk: angličtina
Zdroj: International journal of environmental research and public health [Int J Environ Res Public Health] 2022 Feb 14; Vol. 19 (4). Date of Electronic Publication: 2022 Feb 14.
DOI: 10.3390/ijerph19042125
Abstrakt: The impact of ventilation efficiency on radon ( 222 Rn) and carbon dioxide (CO 2 ) concentrations in the indoor air of a residential building was studied by applying transient data analysis within the CONTAM 3.4 program. Continuous measurements of 222 Rn and CO 2 concentrations, together with basic meteorological parameters, were carried out in an apartment (floor area about 27 m 2 ) located in Ljubljana, Slovenia. Throughout the experiment (October 3-15), frequent ventilation (several times per day), poor ventilation (once to twice per day) and no ventilation scenarios were applied, and the exact ventilation and occupancy schedule were recorded. Based on the measurements, a transient simulation of 222 Rn and CO 2 concentrations was performed for six sets of scenarios, where the design ventilation rate (DVR) varied based on the ventilation requirements and recommendations. On the days of frequent ventilation, a moderate correlation between the measured and simulated concentrations ( r = 0.62 for 222 Rn, r = 0.55 for CO 2 ) was found. The results of the simulation indicated the following optimal DVRs: (i) 36.6 m 3 h -1 (0.5 air changes per hour, ACH) to ensure a CO 2 concentration below 1000 ppm and a 222 Rn concentration below 100 Bq m -3 ; and (ii) 46.9 m 3 h -1 (0.7 ACH) to ensure a CO 2 concentration below 800 ppm. These levels are the most compatible with the 5C_Cat I (category I of indoor environmental quality, defined by EN 16798-1:2019) scenario, which resulted in concentrations of 656 ± 121 ppm for CO 2 and 57 ± 13 Bq m -3 for 222 Rn. The approach presented is applicable to various types of residential buildings with high overcrowding rates, where a sufficient amount of air volume to achieve category I indoor environmental quality has to be provided. Lower CO 2 and 222 Rn concentrations indoors minimise health risk, which is especially important for protecting sensitive and fragile occupants.
Databáze: MEDLINE