Radon and moisture impacts from interventions integrated with housing energy retrofits

Abstract

Energy retrofits can reduce air exchange, raising the concern of whether indoor radon and moisture levels could increase. This pre/post‐intervention study explored whether simple radon interventions implemented in conjunction with energy retrofits can prevent increases in radon and moisture levels. Treatment homes (n = 98) were matched with control (no energy retrofits or radon intervention) homes (n = 12). Control homes were matched by geographic location and foundation type. t‐tests were used to determine whether post‐energy retrofit radon and moisture level changes in treatment homes significantly differed from those in control homes. The radon interventions succeeded in preventing statistically significant increases in first floor radon using arithmetic (p = 0.749) and geometric means (p = 0.120). In basements, arithmetic (p = 0.060) and geometric (p = 0.092) mean radon levels statistically significantly increased, consistent with previous studies which found that basement radon levels may increase even if first floor levels remain unchanged. Changes in infiltration were related to changes in radon (p = 0.057 in basements; p = 0.066 on first floors). Only 58% of the change in infiltration was due to air sealing, with the rest due to weather changes. There was no statistically significant association between air sealing itself and radon levels on the first floor (p = 0.664). Moisture levels also did not significantly increase.

Seasonal Variation of Indoor Radon Concentration Levels in Different Premises of a University Building

“…Radon 222 Rn is an odorless and colorless radioactive gas [1,2]. It is formed from the decay of 226 Ra, which is a member of the 238 U decay chain [3][4][5].…”

“…Aquilina and Fenech (2019) studied the influence of various meteorological parameters on indoor radon levels in four different locations in the Maltese Islands and found that indoor radon levels mostly depended on the outdoor relative humidity and wind speed [24]. The majority of the studies on indoor radon levels and their seasonal variations were performed in dwellings [1,10,13,23,25]. However, some studies were performed on indoor radon levels in workplaces, such as offices and industrial buildings [26][27][28][29], hospitals [26,30,31], and schools [26,32].…”

Radon levels and indoor air quality after application of thermal retrofit measures—a case study

“…As it will be discussed further, type of flooring could be a reason of this large indoor radon variability. An active radon mitigation system implies covering of porous floors with appropriate covers or materials which prevent radon leakage (Francisco et al 2020 ).…”

Indoor environmental quality, energy efficiency and thermal comfort in the retrofitting of housing

“…Other studies concluded that materials like granite and other stones used in older houses may increase radon levels, while over-pressurized ventilation systems may decrease radon levels (Collignan et al 2016). In crawl spaces, ventilation can also decrease radon when it is emitted by construction materials, rather than by the soil or foundations (Francisco et al 2020).…”