Quantification of the impact of temperature difference between two connected indoor spaces on 222Rn concentration. (February 2019)

• Record Type: Journal Article
• Authors: Ratiko, ; Moriizumi, J.; Yamazawa, H.; Nasruddin,
• Is Part Of: Building and environment. Volume 149(2019)
• Page Start: 322
• Page End: 329
• Publication Date: 2019-02
• Subjects: Temperature difference-driven flow -- Radon-222 concentration -- Decrease rate -- Very low airflow measurement; Buildings -- Environmental engineering -- Periodicals; Building -- Research -- Periodicals; Constructions -- Technique de l'environnement -- Périodiques; Electronic journals; 696
• DOI: 10.1016/j.buildenv.2018.12.006
• Languages: English
• ISSNs: 0360-1323

Abstract

Abstract: Dependence of the indoor 222 Rn concentration on the temperature difference between two adjacent indoor spaces or rooms was investigated. The variations in 222 Rn concentration in a vessel with two orifices were measured at various inner-to-outer temperature differences, and were numerically modeled based on a theoretical consideration on the static pressure difference. An equation to calculate the decrease of 222 Rn concentration as a function of the temperature difference between two adjacent spaces was developed. The calculation results using the developed equation in this study, if the drag coefficient of the orifice flow was properly formulated as a function of the Reynolds number, were consistent with the measurement results. The equation developed in this study can be applied to the real case (rooms with several orifices). The approach taken in this study can also be performed to measure accurately a very low air flow (Reynolds number < 100). Highlights: This study can contribute to realistic modelling of indoor radon concentration change. An equation of radon concentration vs. air temperature difference is proposed. The air temperature difference in the equation is between two adjacent spaces. The two adjacent spaces can be indoor-indoor or indoor-outdoor spaces. The approach taken in this study can investigate a very low air flow (Re < 100).