For a deep understanding of the airflow in an environment of historic wooden trusses, it is necessary to analyze the object using simulation methods. To calculate the amount of air passing through the structural openings (components) using dynamic simulation, multi-zone network models based on the simplicity of modeling the individual zones are suitable. For a more detailed analysis of airflow and temperature distribution within one space, a computational fluid dynamics (CFD) simulation model was performed. The air volume through openings and surface temperatures was adopted from the multi-zone airflow network model. By using this simulation technique during a sunny summer day four characteristic states of air movement were simulated in the attic: more intense flow at noon and at midnight caused by a large temperature difference between air and surrounding surfaces and, subsequently, less intense flow when the air was mixed up effectively. The temperature distribution in the cross-sections did not only indicate an increase in temperature with increasing height (up to 50 °C at noon) but also a temperature increase near the southern roof. The surface temperature of the masonry walls was stable (19–33 °C), while the air temperature fluctuated. The image of the flow was completed by ventilation through the tower, which acted as a solar chimney. The airflow through the door to the tower was almost 0.5 m3 s−1 at summer midnight.
The airtightness of buildings is an essential topic regarding energy preservation. The development of new and more sophisticated materials and technology approaches is inevitable. Uncontrolled infiltration is undesirable in buildings with lower energy demands with regulated ventilation. Envelope structure, building method, quality, and others are the main factors influencing the airtightness of the building. However, the correlation between airtightness and climatic factors is less known and researched. This paper comprises measurements of a critical timber-house corner in climatic chambers. It captures the correlation between airtightness and gradual temperature and relative humidity adjustments, simulated from the exterior side. The initial timber moisture content was 12%, and during the experiment it increased with the exterior conditions to 18%. Afterward, we simulated conditions causing a humidity decrease while measuring airtightness. The drying process caused a decrement in airtightness by 18%. In addition to this experiment, this paper also analyses two methods of an airtight membrane connection—constricting or taping the contact. The discrepancy between those two methods was more than 21% in favor of tape.
Measuring climate data is a lengthy and technically challenging task. To record temperature data, small meteorological stations are located on the facade of the Research Centre building. Due to the position of the meteorological stations, which are mounted directly on the facade of the building, the temperature measurement sensor is not only affected by the solar radiation falling on the sensor housing, but also by the solar radiation falling on the facade of the building. The illuminated surface of the facade gradually heats up during the day and warms the air flowing near the facade. The temperature readings during the day may therefore be significantly distorted. To avoid this phenomenon, better-quality radiation shields have been purchased. The new radiation shield is characterized by a design that resembles eddy currents. The relationship between the shape of the outer and inner spiral is optimized, allowing vortices to form even in virtually windless conditions. In this paper, we would like to point out the differences in the measured air temperature data, according to the radiation shield used and the distance of the temperature sensor from the building facade.
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.