The main aim of this work is to develop a numerical prediction method of solar heat gain for coupled analysis of radiative and convective heat transfer which can be applied to a three dimensional complicated geometry incorporating the effect of obstructions and surrounding buildings. The solar radiation (short-wave radiation) analysis has two stages as follows; (1) Analysis of incoming solar radiation (direct, sky-diffuse, and ground-reflected diffuse radiation) inside and outside surface elements: The incident direct solar radiation depends on the glazing transmittance and judging whether the direct solar radiation is obstructed by other walls. The incident diffuse radiation from the sky-diffuse radiation and the ground are calculated by assuming the simplification of an isotropic sky model and an overall albedo of the ground. This requires only the calculation of the view factors between the window and the ground & sky. (2) Analysis of internal reflections: The reflected component of the incident solar radiation for each surface element is simulated using the Radiosity Method. The absorbed heat quantity of solar radiation inside the surface elements is calculated based on the amount of solar radiation reaching inside and outside the surface element. Computation of the absorbed heat quantity is separated by the transmissive performance of walls. In the case of solar radiation reaching outside of the surface element on the opaque wall, the absorbed heat quantity is equivalently converted to one inside of the surface element. The verification of the validity with this system is confirmed by comparing the measured and predicted solar radiation reaching each wall in the experimental real-scale atrium. As a result, the solar radiation reaching each wall can be predicted within accuracy of 10%. Four components of solar radiation must be considered to predict the solar heat gain accurately. The described analysis is applied to a model room including obstructed surfaces. The distributions of absorbed solar radiation are first predicted. The distributions of surface temperature, heat balance on each wall, and mean air temperature are predicted by heat transfer analysis to demonstrate the performance of this method.

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A temperature-stratified thermal storage tank is known as a high performance storage tank. However, it is difficult to apply to the shallow space such as underground floor, because the technique of forming the thermal stratification have not been accomplished. The multi-port diffuser was designed to achieve the sufficient thermal stratification in the shallow depth tank by approximate equations which predict the thermal storage performance conveniently. At the first step of this study, the adequacy of designing was investigated by experiments on the actual system, and the storage performance predicted at the early stages of designing was confirmed. And the second step of this study, the storage performance of the stratified storage tank was studied in order to improve the performance by experiments using a small scale model. So that, if the direction of inlet/outlet was changed from horizontal type to vertical one, the performance was greatly improved.

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It is very important for industry to clarify the shape of a pipe fitting with the branching angle of 135° which has small energy loss caused by flow dividing in turbulent flow. In this paper, before the shape is investigated, the results are reported which were obtained by the theoretical analyses and experiments in the laminar flow for the pipe fitting with sharp edged lateral entrance which is the most fundamental shape.

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For the sustainable society, sparing tap water and energy in urban life is one of keys in solving the problem of resource and environment. In general, the rain water storage facility has been projeted to use rain water for non-potable water instead of city water. But the rain water should be used for many other aspects. The one is to use for cooling water. It is essential to evaluate the ability of rain water used for cooling water as an unused energy. In this study, the rain water storage facility of the R system in which the rain water is used for saving city water and cooling a refrigerating unit has been analysed to evaluate the performance in saving of city water and energy. The R system has an artificial set of open channel and pond serving as a favorable waterscape. The rain water used for cooling water is cooled and regenerated by the artificial set in the R system. A simulation program has been developed to calculate the amount of water and electricity saved by using rain water for grey water and cooling water. Several numerical runs were conducted by the simulation program and the water and energy saving properties of the R system were evaluated.

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A second-story open-plan office building having a void space facing the large window to gain solar energy for space heating was constructed in a northen village of Iwate Prefecture. The thermal design conception for this building is unique in the following terms: (1) Considering passive solar performance, thermal mass, insulation and solar collection techniques were utilized; (2) A longitudinal displacement ventilation system was installed for energy-effecient mechanical ventilation; (3) For energy conservation of heating/cooling and thermal comfort, radiative heating/cooling-dehumidification panels with small-capacity heat generators were installed and they are operated continuously with constant low-power to avoid strict temperature-humidity control, i.e., allow fluctuations of them. To obtain the fundamental information for the thermal design with such a "semi-passive control" conception, several measurements were conducted. This paper describes the conception and reports measurement results of the ventilation airflow volume and the airtightness. And the long-term measurement result of indoor temperatures and humidities is discussed. As conclusions, the measurements described in the above confirm that the unique design conception is reflected in the actual performance.

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Recently an electricity demand tends to expand in Japan. The main cause is that the air-conditioner is operated for long time in the residence. Since an insulated and airtight house is able to reduce the heat load, the house is expected as one of the methods for energy saving. However, in Kyushu area where the cooling period is apt to get long, and the air-conditioners are spread widely, some other methods that are able to consider even the life-styles besides the residential specification are demanded. That is because an effect of energy saving using insulated and airtight house in the summer is less than the one in the winter. The purpose of this paper is to examine the influence of a climate condition, a residential specification and a life-style on the residential electricity consumption for cooling in Fukuoka. The results warrant the following conclusions. (1) Annual electricity consumption for cooling of the detached house in Fukuoka is 1/3 times of Naha and 6 times as large as the consumption in Sapporo. (2) In Fukuoka, annual electricity consumption for cooling of the insulated and airtight house is 3.5 times as large as the consumption of the conventional one. (3) In case that life-style is completely same, it is estimated that electricity consumption for cooling of the insulated and airtight house will increase from the conventional one. However, in case that air-conditioner is almost operated all day long in the insulated and airtight house, the consumption will get larger than in the conventional one. (4) As the residential specification in Fukuoka, to use a natural ventilation and a solar shading besides an insulation and airtightness is indispensable.

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The purpose of this study is to estimate the reliability level for building facilities. In the previous paper Part 1, we proposed the Reliability Interval Estimation Chart, and we analysed the field data by using the two kinds of interval estimation methods. Moreover, we discussed the Bayesian method in estimating the MTBF, and then analysed it by using the data of building facilities. Then in the previous paper Part 2, we proposed our estimation and evaluation on many parameters of the failure time distribution by computer simulation. We simulated random numbers of the exponential distribution, normal distribution and Weibull distribution by the probability paper method, likelihood method and the Bayesian method. And we discussed these results and the interval estimation etc.. Moreover we simulated the building facility in the random failure rate. Now, this present report is concerned with the evaluation by the reliability model and the stated transition method. Firstly, we estimate many reliability models using the block diagram. Next we use the stated transition method. And we evaluate both above two methods (i.e. the reliability model and the stated transition) and using the Reliability Interval Estimation Chart. Last the authors believe that an extremely practical result in processing field data has been obtained for the maintenance and design of building mechanical/electrical service systems and equipments.

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This paper deals with fluidization and heat storage characteristics of shape-stabilized latent heat storage pellets packed into a fluidized bed-type heat storage vessel. The shape-stabilized latent heat storage material consists of normal paraffin (pentacosane C_<25>H_<52>, latent heat 164kJ/kg, melting point of 327.2K) as a latent heat material, and polyethylene as a shape-stabilizing material. The pressure losses both on fluidized and on fixed particle layers were measured in order to investigate flow behavior in the heat storage vessel. It was found that the pressure loss of the fluidized particle layer was lower than that of the fixed particle layer. Furthermore, the effects of hot air flow rate, inlet air temperature and the amount of heat storage particles packed into the heat storage vessel on the completion time of the heat storage process were investigated. As a result, the nondimensional correlations for the completion time of the heat storage process were expressed in terms of nondimensional pumping power, the Stefan number and the ratio of the packed particle layer height to the diameter of the cylindrical heat storage vessel.

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Usually airflow in subway systems has been predicted by macroscopic models founded on the assumption that the airflow is one-dimensional. In order to establish three dimensional distribution of airflow within a subway station, it is necessary to apply some microscopic models based on computational fluid dynamics (CFD). However the application of microscopic models to the whole subway system needs heavy computation loads. The practical and proper way is to apply a microscopic model to the target space and a macroscopic model to the surrounding space. In this paper, the two-way model, in which microscopic and macroscopic models are coupled simultaneously, is developed and applied to an ordinary type of subway station. In this microscopic simulation, the distribution of airflow in the concourse and the platform are predicted. Its validity is confirmed by comparison with measured data. The one-way model, in which the microscopic model is calculated only once using the results of the macroscopic model, is also applied to the same station. There is little difference in the results between the one-way and two-way models. And the computation load in the one-way model simulation is about 1/10 of that in the two-way model simulation. Except for a case where the structure of a station causes high airflow impedance, it is convenient to apply the one-way model to ordinary types of subway stations regarding computation load.

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In this study, the characteristics of airmass and heat transport within an atrium are systematically analyzed by means of model experiments. In previous paper, part 1, model experiments neglecting radiative heat transfer in the space were carried out in order to examine the influence of convective heat transfer through the walls on flow and temperature fields within a model atrium under occupied zone cooling. In this paper, experiments considering both radiative and convective heat transfer in the space were systematically carried out in order to analyze how the heat flux given at the wall surface are distributed into convective and radiative heat transfer. The mechanism of the formation of the indoor thermal environment by the convective and radiative coupled heat transfer is analyzed. The results of the analysis are the following: (1) the heat flux through the ceiling has considerable influence on the indoor thermal environment, (2) most of the heat flux through the ceiling is transmitted to the floor and the lower part of the walls by radiation, (3) and this radiative heat transfer between the ceiling and the floor considerably influences on vertical temperature distribution and the height of cooled zone space for occupancy by convection.

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