文献一覧: 梅野徹也 (著者)

3 0 0 0 OA 通気層内温湿度変動の実態把握壁体内通気層における防露性能の実態に関する研究その2

著者: 梅野徹也鉾井修一齋藤宏昭本間義規
出版者: 日本建築学会
雑誌: 日本建築学会環境系論文集 (ISSN:13480685)
巻号頁・発行日: vol.81, no.729, pp.951-959, 2016 (Released:2016-11-30)
参考文献数: 17
被引用文献数: 1 2

Most exterior walls of wooden residential buildings in Japan have a vented air space between the exterior cladding and insulation. This air space is designed to dehumidify exterior walls by discharging humidity to the outside and taking outdoor air into the walls, in order to decrease the risk of condensation on exterior walls in winter. Many studies have been carried out on vented air space, and the most effective thickness for dehumidification has been determined. However, most of these studies have only investigated the performance of vented air spaces under laboratory conditions, and the characteristics of vented air spaces in the field have not been clarified. Our previous study clarified the characteristics of ventilation volume through the vented air space based on field measurements. This study continues that work by reporting on the hygro-thermal characteristics of vented air space. Temperature and humidity were measured in an experimental house built in Iwate prefecture, and the hygro-thermal characteristics of the vented air space were verified. Temperature and humidity in the vented air space were affected by the outdoor temperature and humidity during most periods of time, except when the wall was exposed to solar radiation. Indoor temperature and humidity had less of an effect on the vented air space, because the walls of the experimental house are well insulated and highly moisture proof. The temperature of the vented air space is 20 or 30 degrees higher than the outdoor temperature when exposed to the sun during the day, and the humidity of the vented air space also rises. It is thought that the rise in humidity is due to moisture desorption from the exterior cladding. The vented air space of the east wall that is exposed to the sun in the early morning tends to have high humidity for a short time because moisture desorption from exterior cladding occurs when the temperature of the wall is low. Solar radiation on the wall also produces a temperature difference between the vented air space and the outside that is one of the driving forces of ventilation in the vented air space. So ventilation volume tends to be high when the wall is exposed to the sun, and low at night time. This means that ventilation volume in the vented air space is high during moisture desorption from the exterior wall cladding and low during moisture absorption. As a result, most of the desorbed moisture from the exterior cladding is discharged well by the ventilation, and the absolute humidity in the vented air space is kept lower than that outdoors. Through long-term measurement of the hygro-thermal characteristics of the vented air space, it was shown that absolute humidity of the vented air space is lower on the average than the outdoor air due to daily variation in ventilation volume and moisture absorption by the exterior cladding. A numerical simulation was conducted and the results of the field survey were simulated. The hygro-thermal characteristics of the vented air space, moisture absorption by the exterior cladding and drying of the vented air space over the long term were generally confirmed.

2022-08-14 09:40:23
3 + 3 Twitter

1 0 0 0 OA 壁体内通気層における防露性能の実態に関する研究実験住宅における通気量の実態把握

著者: 梅野徹也鉾井修一齋藤宏昭本間義規
出版者: 日本建築学会
雑誌: 日本建築学会環境系論文集 (ISSN:13480685)
巻号頁・発行日: vol.78, no.694, pp.909-916, 2013-12-30 (Released:2014-07-10)
参考文献数: 14
被引用文献数: 2 2

Most exterior walls of wooden residential buildings in Japan have vented air space between the exterior cladding and the insulation, which is designed to dehumidify the exterior walls by discharging humidity to the outside and taking outdoor air into the walls, with the purpose of decreasing the risk of condensation in exterior walls in winter. Several studies have been carried out on the vented air space, and the most effective thickness for dehumidification has been determined. However, most of these studies have only investigated the performance of vented air spaces under laboratory conditions, and the characteristics of vented air spaces in a field environment have not been clarified. The driving forces of the airflow in the vented air space are the buoyancy force due to the temperature difference between the outdoor air and the vented air space and the wind pressure. However, few studies have dealt with the influence of wind pressure. Since the velocity and the direction of the wind change irregularly, it is difficult to estimate the ventilation volume due to the wind. The objective of this study is to survey the ventilation volume through the vented air space and to investigate the effect of the driving force of the ventilation, which are buoyancy force and wind. Measurements have been carried out on the vented air space in an experimental wooden house that has several types of vented air spaces. The correlation between the ventilation volume and the driving force was discussed.