Experimental Investigation and Accuracy Study of CFD Analysis for Airflow around Cross-Ventilated Building

In predicting flow rate of a building ventilated by wind, the orifice equation is usually used. This conventional method cannot work for the building provided with large openings. Therefore, the final goal of this study is to establish a new prediction method of the cross-ventilation rate, which is based on energy balance inside the stream tubes passing through/around a building. In determining stream tubes, it is beneficial to use CFD. In this study, the accuracy of CFD analysis is studied. Three turbulence models are used in the simulation; i.e.

Adaptation process of human olfactory under continues exposure to odor of ethyl acetate based on subjective estimation of odor intensity

This study was aimed at making a model which predicted olfactory sensation. Firstly, it was conducted the experiment, which odor was exposed to subjects constantly and subjects evaluated odor, to investigate the olfactory adaptation process. As a result, it was turned out odor intensity decreasing exponentially as time. Secondly, validity of the previous theoretical model ( Osako,1991 ) was investigated by comparing the evaluation.

Environment-friendly Hwangtoh composites using water soluble resin for interior materials

The objective of this research was to develop environment-friendly Hwangtoh binder for application of Hwangtoh for interior wall finishing materials in the housing. To mix with Hwangtoh powder, water soluble MPU resin with EVA, PVA, CaCO3 and inorganic fillers were designed. Far infrared ray irradiation, TVOC emission behavior, surface bonding strength and surface crack behavior were studied by comparing to epoxy/Hwangtoh blend as control.

Characteristics on indoor air pollutant emission from wood-based flooring by environmental-friendly natural adhesive using CNSL

To discuss the reduction of formaldehyde and volatile organic compound (VOC) emissions from engineered flooring, cashew nut shell liquid (CNSL)-formaldehyde (CF) resin and CF/PVAc resin were applied for the maple face of the veneer bonding on plywood. The CF resin was used to replace urea-formaldehyde (UF) resin in the formaldehyde-based resin system in order to reduce formaldehyde and VOC emissions from the adhesives used between the plywoods and fancy veneers. For the CF/PVAc resins, 5, 10, 20 or 30% of PVAc was added to the CF resin.

Experimental Assessment of Humidity Controlling the Performances of Moisture Adsorbing/Desorbing Building Materials

The climate of South Korea is that of high temperatures and high humidity in the summer season and low temperatures and low humidity in the winter. Humidifiers and dehumidifiers are used to create a cool indoor environment, and the demand for building materials with moisture adsorption/desorption functions is increasing. To investigate the performance of moisture adsorption/desorption new mineral fiber boards, a chamber test and mock-up test were performed and compared to mineral fiber boards.

Improvement of Temperatures Stratification caused by Air-conditioner by means of Ceiling Fan in Classroom

This paper discusses on the indoor thermal environment controlled by the air-conditioners and the ceiling fans under the heating condition. An experiment which measured the temperature and the indoor wind velocity was conducted in the classroom with the ceiling fans. The preset temperature was 24oC, and the airflow direction of the ceiling fans was upward. The rotational speed of the ceiling fans were changed (90-300rpm). Questionnaires to the occupants were also conducted to figure out the problem when the ceiling fans were used in the classroom.

Exhaust effectiveness based on residual lifetime of contaminant in a ventilated space

Exhaust effectiveness indicates how effectively contaminated air can be removed from a space, whereas air change effectiveness indicates how effectively distribute fresh air into the space. It is intended to describe the exhaust effectiveness based on the residual-life-time of contaminant in the context of logical extension of supply effectiveness based on LMA.

Measurement of temperature distribution and CO2 concentration in a space-heated classroom

The winter thermal environment and indoor air quality in classrooms has been reported to be very poor in Japan. In this study, an air-conditioned, mechanically ventilated classroom was surveyed. Air temperature, globe temperature and the concentration of CO2 were monitored before, during and after the three-hour occupancy by 35 adults. Airtightness and airflow rates of the ventilation system were also measured.

Natural Ventilation in Thai Hospitals: A Field Study

Natural ventilation has been appraised as the main strategy in environmental control of airborne infection in resource-limited healthcare facilities. While natural ventilation offers a low-cost alternative in diluting and removing contaminated air, its’ performance in actual settings is not fully understood. This paper reports a cross-sectional field study of six hospitals in Thailand with an emphasis on ventilation performance of naturally-ventilated hospital wards and AII rooms. The results showed that ventilation rates of 3-26 ACH could be achieved in hospital wards.

Dynamic Insulation System applied to Window Frames (Part 2) - Energy saving effects of the proposed system in residential buildings

This paper describes the energy-saving effects of the proposed system with an active ventilation function and a heat pump for heat recovery. First, the temperature of the air supplied through the porous material versus the outdoor temperature was calculated using computational fluid dynamics to set the boundary conditions for the energy simulation. Then, the cooling/heating loads of a typical residential building in Japan were calculated and comparisons were made with and without the proposed system installed.

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