The present paper is a sequel to the previous report and describes scale model studies on the natural ventilation of a factory building with large heat sources through air inlet openings in the working floors. As described in the previous paper, for natural ventilation caused by the density difference between columns of outdoor and indoor air, the values of the Archimedes number in the model and under natural conditions are automatically equal. Apart from geometric similarity, therefore, only thermal similarity is needed to simulate natural ventilation conditions. Regarding thermal similarity, the heat flow by ventilation is assumed to equal the amount of heat generated in the factory. The automatically applicable similarity in natural ventilation permits selection of any ratio of surplus heat under natural conditions and the model when setting up an experiment according to the test conditions. The temperature difference ratio of natural ventilation dose not depends on the rate of surplus heat, but on such geometric conditions, as the area of the open inflow or extract vents, vertical distance between the center of the lower and upper apertures, and the layout of the heat sources. A stratification method using the temperature difference ratio requires a smaller area for the vents than the conventional method and thus makes ventilation designs more economical.

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In this paper, we deal with the method of calculation water consumption for design of piping and water uses in multi-storey flats. The current design procedure which is used to determine the size of piping is the Hunter's method utilizing fixture unit, but with this method we cause several problems such as over design of piping. Here, the results of one study based on the actual investigation of two multi-storey flats are described as follows; 1) The amounts of water consumption in various uses are analysed. And we explain that we can save the amounts of water by taking various means in using water. 2) The patterns of use of water outlets are investigated. And it becomes clear that the probability of simultaneous uses of water outlets can be approximated with the Poisson distribution. 3) A procedure that is used for the probability of simultaneous uses of water outlets is suggested for flow rates design. The calculated results based on investigated data of the probability, give small values in comparison with the Hunter's loading curve.

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Part 1 and part 2 disscussed the measurement of offensive odors in wastewater by the "Head Space Method" and the factors that govern the diffusion of offensive ordors. This report discusses the engineering phenomena by applying the "Head Space Method", and, 1) the quality and quantity of offensive odors generated at each process of a municipal aerobic biological sewage treatment plant. 2) the introduction of the Head Space Method into the equation of diffusion model for offensive odors generated on the water surface. 3) the relationship between offensive odor concentration and the sense of smell from the generated offensive odor.

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The thermal storage tank is attracting the attention of engineer's for its importance in the economic design of air-conditioning systems. Many valuable studies on it have been reported in recent years. Most of these studies attempt to clarify its characteristics as a separate element. However it should be noted that the behavior of a certain device is substantially affected by the characteristics of the other parts of the system. This paper investigates the dynamic behavior of the thermal storage tank as an element within a larger system containing a cooling coil, refrigerator and control devices. A mathematical model of the system is non-dimensionalized and simulated on a digital computer. In non-dimensionalizing, we used only those parameters which are supposed to be given as design specifications. The behavior of the model was found qualitatively well acceptable. The so-called "efficiency of thermal storage" has been widely used in designing thermal storage tanks. This is based on the "design storage temperature" and "return temperature from the coil", but the method of estimating those two values is not yet firmly establised. This paper proposes some Characteristic Values which provide much valuable information on the system, especially its dynamic behavior and play an important role in the design procedure to be described in Part 2.

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A thermal storage tank system must be at least able to eliminate the given heat load in the cooling mode. Some researchers have pointed out serval other merits in installing a thermal storage tank in an air-conditioning system. This paper is mainly concerned with the function of the thermal storage tank that eliminates the heat load peaks and reduces the required capacity of the refrigerator. During the study along this line, the concept of "proper heat load to the tank" is introduced. If the heat load to the tank is too low, the tank may not work effectively in the system. On the other hand, if it is excessive, the tank may be overloaded. One of the Characteristic Values proposed in Part 1 was found useful as a good criterion in judging whether the heat load is proper or not. A proper balance between the capacity of the cooling coil and that of the refrigerator is crucial in attaining the proper tank heat load. This point is described in some detail in quest of the optimal design procedure. The effects of the size and pattern of the heat load and the flow pattern within the tanks are also investigated, and some interesting results are obtained.

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The storage tank efficiency of Multi-connected Complete-blending tanks, which are the most popular in Japanese thermal storage systems for buildings, is effected by factors related to system design as well as the structure of the tank, such as the number of tanks. The authors qualitatively analyzed the effect of the most important factors, then reduced the number of factors by non-dimensioning. In order to ascertain what kinds of factors really affect efficiency, and to prepare a simple estimation table for any combination of factors, the authors used the design of experiments method in which experiments are replaced by computerized system simulation. The interaction between factors was evaluated qualitatively as well as quantitatively, and the accuracy of the estimation table was confirmed by camparing the efficiency values and temperature profiles between the estimated values and the simulated values.

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The characteristics of solar energy systems with reflecting devices are studied. These systems consist of flat plate type solar collectors or solar cells and flat plate reflecting devices. Because reflecting devices are exposed to the elements for a long period, the collection of data on the deterioration of reflecting performance is extremely important. Several reflecting materials were exposed outdoors for a long period, and their change of reflectance was measured. Then formulae to predict the incident insolation on collectors or cells with reflected light gathering systems were developed. This formulae were verified by comparing the calculated values to the measured values. These measured reflectance and verified incident insolation predicition formulae are used to calculate the increase in the annual collected heat and generated electricity obtained by using reflecting device. The results clearly show that the appropriate reflecting devices arrangement improves total system performance and economy.

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This report considers the relationship between the water supply and drainage systems and describes experimental studies on the influences of selfsiphonage on water seal loss. These experiments were perfomed by changing the slope of the bottom plate in the fixture, the shape of the outlet and joints, the length and diameter of the branch pipe and other factors which seem to have an influence on selfsiphonage. Two cases were considered. One was washing with running water and the other was washing in filled water. Three model fixtures and an actual wash basin were used in the experiments. The movement of the water in the drainage pipe was observed and the water seal loss in the traps, the occurence of plug flow and the pressure in the pipe were analysed. These studies show that the slope of the bottom plate in the fixture has the most affect on the water seal loss.

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This paper continues from where the first part of the paper ended and examines the transform mechanism of building pulmbing systems. The transform coefficients are defined so the transform mechanism can be handled quantitatively. For quantitative conversion, the coefficients for sanitary fixtures and standard drainage piping are calculated from the results of analysis of the experiments and data shown in the first part of the paper. The peak drainage flow rates are estimated from the peak water supply flow rates of the sanitary fixtures by using these transform coefficients. The authors verify these coefficients by estimating the peak drainage flow rates of the model piping and show that they are the proper coefficients. An example in which water usage accummulation by time frame is considered is given for a residence of an appartment house. The authors show that the peak drainage flow rates can be estimated by peak water supply flow rates multiplied transform coefficient as described above.

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A ventilation model consisting of piston flow and dilution parts in parallel is introduced, where each part of the flow is classified from its area deviation into piston flow part or dilution part. Next, model rooms with different exhaust positions and various treatments of flow character are used in numerical solutions, to investigate the air flow model above mentioned. How the potential flow is available on the ventilation model to estimate the ventilation capability is as investigated. The result clarifies the following points. 1) When the air flow in the room is regarded as a laminar flow of Re=100, the results of estimation of the ventilation capability using the ventilation model coincide with the experimental results. 2) The potential flow is available on the estimation of ventilation capability only when the room has a large dilution part.

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