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Matsuoka D.,POLUS R and D Center of Life Style Inc. | Hokoi S.,Kyoto University | Saito H.,Ashikaga Institute of Technology
ASTM Special Technical Publication | Year: 2015

A mock-up study was conducted with a one-story test house (3.64 m by 3.64 m) with eave ventilation in a suburb of Tokyo to examine the hygrothermal conditions in an attic space. A series of measurements were conducted to clarify the effects that the vent opening area and vented wall cavity had on the hygrothermal conditions. Additionally, a hygrothermal simulation was conducted based on the results of the experiment to estimate the amount of airflow within the attic space. The main findings from the experiment and simulation results are as follows: 1. Considering that 20 % of the upward airflow through the vented wall cavity does not contribute to ventilating the attic space, the eave space should be incorporated into the hygrothermal model in order to predict the proper size of an attic ventilation opening. 2. The airflow (advection) between the insulation mats to the attic space was found to be 2-20 m3/h (equivalent to 0.2-2.0 times/h air exchange rate in the attic space). The average vapor flow by advection was approximately 2.5 g/m2h at night (0:00 to 6:00), and the average attic absolute humidity increased by 0.2 g/kgDA during this period. 3. The amount of moisture absorbed and/or desorbed by the wooden materials in a daily cycle is almost the same as that absorbed by the northern and southern sheathing boards, and thus had a significant effect. It should be considered when calculating the temperature and humidity in an attic space. Copyright © 2015 by ASTM International. Source


Matsumoto T.,POLUS R and D Center of Life Style Inc. | Matsui I.,Nihon University
Journal of Environmental Engineering | Year: 2010

There are two kinds of Thermal-Sensation research: climate chamber research and field research. Field research has the advantage of normally, so that peoples' responses are likely to be similar to those in daily life, and the environments fairly typical of the normal housing stock. This paper describes the experimental result on the effect of heating of soles on Thermal-Sensation of subject in winter real void-space. The results are as follows; The relationship between room temperature and thermal sensation votes was determined. Using a primary approximation line derived from an approximation line formula, we found the room temperatures at which the thermal sensation throughout the body was neutral. This room temperature was 23.8°C when soles were unheated, 20.2°C when soles were heated. We found that direct contact heating of the soles has a greater effect on thermal sensation throughout the body wholes in winter real void-space. Source


Matsuoka D.,POLUS R and D Center of Life Style Inc. | Hokoi S.,Kyoto University | Saitou H.,Ashikaga Institute of Technology | Tsuchimoto T.,Japan Building Research Institute
Journal of Environmental Engineering (Japan) | Year: 2014

Amock-up test was conducted with a one-story test house (3.64m by 3.64m) with eaves ventilation in the suburb of Tokyo to examine the hygrothermal conditions in an attic space. Aseries of measurements were carried out to clarify the effect of the vent opening area, an air stopper insulation in the partitioning, and the vented cavity of outer wall on the hygrothermal conditions. Main findings from the experiments are as follows; 1. The absolute humidity in the attic space is hardly changes from midnight to early morning. Condensation on the surface of sheathing roof board occurs because the nocturnal radiation and outdoor temperature reduces the surface under dew-point. 2. The surface absolute humidity of the lower part of the north facing sheathing roof board gradually decreases in the afternoon, with keeping higher values than those of the central part and the attic space air. This is probably because the moisture content in the lower part is higher than that at the central part. 3. Occasionally, the absolute humidity in the attic is lower than outdoors. 4. The attic space-connected vented cavity contributes to keeping low humidity in the attic air since the influx air is drier than the outdoor air. This contribution ratio is not low, so the inclusion of its effect is necessary for examining ideal ventilation areas. Source


A mock-up, one-story test house with eaves ventilation was built in a suburb of Tokyo to examine the hygrothermal conditions in its attic space. A series of measurements were conducted to clarify the effects that the vent opening area and vented wall cavity had on the hygrothermal conditions. In addition, to estimate the airflow rate through the vented wall cavity and eaves vent using the air velocity measured by an anemometer placed therein, the relationship between them was measured by changing the fan flow rate in an experimental setup. The dehumidification of the attic space by the eaves vents, vented wall cavities and room was calculated during the experimental period. The main findings are as follows: 1) Of the total flow rate through the vented wall cavity on the southern side, the proportions among upward flow into the attic space, upward flow into the ventilation opening, and downward flow were approximately 5:1:4. 2) Considering that 20% of the upward airflow through the vented wall cavity did not contribute to the ventilation of the attic space, the eave space should be added as a calculation node for hygrothermal models to predict the proper size of the attic ventilation opening. 3) Glass fiber insulation wrapped a vapor tight film (bagged insulation) is generally employed as a insulation layer of ceiling in mild climate regions of Japan. The air gap between the insulation materials has an impact on moisture flow passing through the ceiling gypsum board to the attic space. Source


Hagihara K.,Kyoto University | Iba C.,Kyoto University | Hokoi S.,Kyoto University | Matsuoka D.,POLUS R and D Center of Life Style Inc.
Energy Procedia | Year: 2015

Today, promoting the use of abundant renewable energy such as underground heat has become imperative. The preservation of the traditional wooden dwellings unique to Kyoto called Kyo-machiya has recently become a priority policy in Kyoto. However, owing to the poor airtightness and thermal insulation of Kyo-machiya, these dwellings require considerable energy to heat during winter. However, most Kyo-machiya are equipped with a well, and this study employs experiment and analysis to examine the practicablity of installing simple ground-sourced heat pump systems in the existing wells of Kyo-machiya. The efficient operation of the heat pump system is also investigated. © 2015 The Authors. Source

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