This study investigated the feasibility of using the spatial distribution of expiratory aerosols and thepercentage viability of airborne viruses to estimate the spatial exposure levels of airborne viruses inrooms under imperfectly mixed condition. Experiments were conducted in a hospital ward withceiling-mixing type ventilation system. A broth solution with a known concentration of bacteriophages,as to simulate airborne viruses, was aerosolized with a droplet size distribution similar to humanexpiratories. Spatial distributions of these aerosols were measured using an aerosol spectrometer.
Total heat exchanger model based on experimental results was incorporated in the entire buildingmodel with the stay and internal generation of heat and with window opening-closing schedule, andenergy-saving effects of total heat exchangers were evaluated including regional features in Japan.Regional differences were found in the effects, and it was found that the reduction rate of heating andcooling loads was in the range of about 2 15%, and the reduction amount of heating and coolingloads was in the range of about 0.1 11 GJ.
Introduced in late 90’s, Impinging Jet Ventilation (IJV) is the system that can utilize stratification, while supplying with medium to high velocity. This characteristic makes IJV easy to be controlled and operated, while room Indoor Air Quality (IAQ) can
The concept of a ventilated double façade is invented with the intention of improving the thermal qualities of a fully glazed façade. Over the years, the properties of the single glazed façade have improved. The aim of this study is to compare different v
Outbreaks of Sick Building Syndrome (SBS) first gained attention in the 1970s in the USA, with thedevelopment of more energy-efficient buildings that depend on mechanical ventilation systems tocirculate fresh air, as well as to control air temperature and sometimes humidity.SBS at office building and so on is not such a severe problem, but, a similar syndrome has beenrecently reported with increasing frequency in airtight new houses in Japan, that is, Sick HouseSyndrome (SHS). We have conducted the survey concerning SHS in Fukushima city, northeast area ofJapan since 2003.
The double-glazed external wall (double-skin) system is an effective passive technique that candecrease solar heat gain into the building. Detailed information concerning the thermal characteristicsof the double skin is necessary to accomplish a good design for thermal comfort and energy-saving.In this paper, the 3-dimensional thermal characteristics of the double skin that had the openingspartially installed and was partially shaded by the adjacent building were investigated by a fieldmeasurement.
Personalized Ventilation (PV) has been shown to improve inhaled air quality recently. However, it maylead to dissatisfaction such as draft due to personalized air applied locally to the facial region, orstuffiness due to inadequate air supply. This study aims to identify some reasons for the dissatisfactionamong tropically acclimatized people through a systematically experimental design.In this study 24 subjects were subjected to a series of random facial exposure to local air movementeach of 15 minutes duration in a well-controlled indoor air quality chamber.
In the sickroom, high indoor air quality and thermal comfort is essential for the treatment of patients.Therefore it is proposed to use displacement ventilation for the whole room ventilation and the radiantpanel for the thermal comfort of each bed. This study is intended to investigate validity of this system.This paper shows the experimental and calculated results of the displacement-ventilated room with onebed and one radiant panel. The vertical profile of contaminant concentration and temperature aremeasured and compared with the calculated ones.
The epidemiological research on indoor environments in homes and health has been reviewed.Science has mainly been about health effects like asthma/allergies and exposures such as VOCs,mould and dampness. So far there are few conclusive findings. Dampness, pets, mites, dampness,ETS, a low ventilation rate, and some phthalates are risk factors for asthma and allergies. There is alarge need of studies of other health effects, and other exposures, especially regarding new frequentlyused chemicals.
This paper presents the benefit of natural ventilation of a roof cavity to reduce summer thermal loads ofa factory and, therefore, the cooling load due to air-conditioning systems with respect to various climatezones in Japan. A simulation program was developed to analyze the impact of cavity ventilation on theoperative temperatures of the occupied zones in a factory. Three climate zones in Japan: cold region(Sapporo), temperate hot-humid region (Tokyo), and subtropical region (Naha) were selected forcomparison. In an air-conditioning mode, two calculations of cooling loads were made.
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