Mold growth poses a high risk to a large number of existing buildings and their users. Air leakage through the air cavities of the building walls, herein gaps between walls and air conditioner pipes penetrating the walls, may increase the risks of interstitial condensation, mold growth and other moisture-related problems. In order to quantify the mold growth risks due to air leakage through air cavity, an office room in a historical masonry building in Nanjing, China, was selected, and its indoor environment has been studied. Fungi colonization can be seen on the surface of air conditioner pipes in the interior side near air cavity of the wall. Hygrothermometers and thermocouples logged interior and exterior temperature and relative humidity from June 2018 to January 2020. The measured data show that in summer the outdoor humidity remained much higher than that of the room, while the temperature near the air cavity stays lower than those of the other parts in the room. Hot and humid outdoor air may condense on the cold wall surface near an air cavity. A two-dimensional hygrothermal simulation was made. Air leakage through the air cavities of walls proved to be a crucial factor for mold growth.Energies 2020, 13, 1177 2 of 20 wall materials is the most important factor triggering the growth of microorganisms. The United States (US) Center for Disease Control stated in its guidance that "elimination of moisture intrusion and leaks and removal of mold" constitutes one of the three crucial interventions for houses implementation [16].Currently, advanced mold prediction models deal with the main influencing factors for mold growth: the surface temperature and relative humidity. Vereecken et al. [17] reviewed the models for mold growth and environmental risk prediction (isopleth systems [18,19], bio-hygrothermal model [20], ESP-r mold prediction model [21,22], VTT model [23]). Abe et al. [24] developed the fungal index to indicate the environmental capacity for mold growth. Hukka et al. [25] proposed a quantitative relationship between mold growth initiation conditions, maximum growth and growth rate. Sedlbauer [26] developed WUFI-Bio software (Klaus Sedlbauer, Department Hygrothermics at the Fraunhofer IBP, Munich, Germany) to assess mold risk by temperature, humidity and substrate in cases of transient conditions.Heat and moisture transfer simulation coupled with suitable temperature and humidity conditions for mold growth can also be used for evaluation [27].Building walls made of porous bricks or stones are easily exposed to outdoor moisture, including wind-driven rain [28] and rising dampness [29]. Additionally, improper energy conservation treatment [30][31][32], including inadequate insulation and unwanted air pathways, may cause thermal bridges and allow the surface temperature to become lower than the dew point of surrounding air, leading to unwanted condensation. Among them, air leakage through an air cavity [33] serves as one of the main moisture-transferring routes, redistributing the temperature and humidit...
Mould growth causes damage and poses high risk to a large number of existing buildings and their users. Air leakage through air cavity of the building walls, such as gaps between walls and some pipes penetrating the walls, produces obvious hygrothermal exchange, altering the temperature and humidity distribution of the walls. It would promote condensation and mould growth. Air cavity are common on the walls of existing buildings. In order to make a quantitative analysis on the mould growth risks due to air leakage through air cavity, an office room in an existing building in Nanjing, China was selected and hygrothermometers were arranged indoor and outdoor for monitoring. The measured results showed the room was in high temperature and relative humidity from June to early September. Two-dimensional hygrothermal simulation was made to investigate the hygrothermal conditions of the walls with air cavity, using the measured data as boundary conditions and validation for the numerical simulation. Mould growth risks under these situations were estimated.
Nanjing City Wall, one of the most important cultural heritages in China, has been damaged in a natural environment for centuries. Plants can be a candidate to regulate the micro-environment and mitigate the influence of local climates, which cannot be easily controlled by human efforts. Therefore, we examined the potential of the roadside trees along the City Wall to buffer the hygrothermal cycles that can deteriorate the City Wall. We surveyed the deteriorated state and measured the temperature and moisture content of the City Wall. Measured results showed smaller temperature fluctuation at shaded surface than the unshaded with a maximum temperature difference of 10.9 ℃ in summer. The measured water content decreased with height. A coupled two-dimensional hygrothermal 'City Wall-plant' model was proposed to clarify the influence of the roadside trees on the hygrothermal distribution of the City Wall. The proposed city wall-plant hygrothermal model could predict the surface temperature and water content well.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.