English

This paper presents further developments in a new study of a hybrid ventilation system suitable foruse in domestic buildings or classrooms. Currently the hybrid system is used solely for providing fresh,warm air. The system consists of a wall-mounted convector unit coupled with an extract fan to drawthe air into the convector. Fresh air from outside is tempered by circulating water around an internalheat exchange coil, before it passes into the room. This allows a constant supply of clean, filtered,conditioned air.

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.

The prediction of plume dispersion near buildings is very important for the design of exhaust stacks andair intakes in order to avoid adverse air quality impacts. However, it is difficult to predict pollutantdispersion with certain accuracy due to the complex interaction between atmospheric flow and flowaround buildings.

This study has explored the possibility and potential of using a thermal active mass system for reducingthe temperature rise and increasing the thermal comfort in an office room. The Controlled Active Mass(CAM) will be used as a heat sink to absorb heat from the room in order to increase the thermal comfort.Physically, the CAM system was designed as a cubic-shaped tank filled with water, with the tanksurfaces either polished or black.

A desiccant air-conditioning system has been suggested as being suitable to improve indoor air qualitydue to its superior humidity control. However, this system has the drawback of being less energyefficient, so it is typically used in conjunction with co-generation systems or solar heating systems toimprove its energy efficiency. In previous studies, we proposed a new type of desiccant air-conditioningsystem combined with a CO2 heat pump, and studied its applicability through experiments andsimplified calculations.

Holonic Energy Systems (HES) refer to systems where distributed generation and centralized powergeneration are organically combined to establish optimal operation, based on a good balance betweenthe whole and its parts, but not on optimization of each part that is the conventional concept ofupgrades in a single energy source. This paper presents an outline of HES proposed by us and threemicrogrid verification test results demonstrated through the activities toward HES. On the test results,reduction rates of CO2 emission of the microgrid operation was above 20% for reference system.

“Tatami” is a traditional Japanese building material used as a floor mat made with rush. It used to be said that the smell of tatami is preferred by many Japanese, because almost all Japanese houses have had tatami rooms since early times. In this paper,

The VOC removal filter for ceiling cassette type air conditioners was developed as a countermeasure against “sick school”. This paper illustrates basic performance of the developed filter, the detail of toluene removal examinations in an experiment room a

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