The number of microorganisms in humidified water was counted and the transmission of microorganisms from humidified water into air was investigated from the hygienic standpoint of humidification in an air conditioning system. The following results were obtained. 1) The recirculating city water and hot water for heating coils and heat storage tank used as humidified water contained a high density of many kinds of microorganisms, such as bacteria, mold, and protozoa. 2) Humidification transmits the microorganisms in the humidified water into the supply air by humidifying so that the air in the room is contaminated. 3) The number of microorgamisms transmitted into the air by humidification depends on the increase in the moisture content in the air and the number of microorganisms in the humidified water.

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The flow mechanisms in a pipe junction in the turbulent flow were studied numerically by using a turbulence model with two different equations-one for the kinetic energy of turbulence, k, and the other for its dissipation rate, ε. The turbulent flow field in an actual pipe junction was also studied experimentally with a model by a flow visualization technique. The results referred to the mean flow obtained by computation and experimentation are compared and the flow mechanisms are discussed theoretically and experimentally.

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It is well known that the local thermal environment is affected by the surrounding land cover such as woods, lawns, asphalt, etc. To quantify this effect, surveys on the thermal environment in a park were conducted. The Japan Expo Memorial Park was chosen as the most suitable site for this kind of survey from the experiences gained from a preliminary survey conducted by authors in another area. The measuring systems were designed to ensure quick and easy readings. These systems made it possible to conduct many field survies without many survey assistants. After repetition of the survey, statistically meaningful results were obtained. The horizontal air temperature distributions 1.5m above the surface of the earth in the park was not so clearly recognizable during the day as at night. It is clear that the night-time temperature distributions are related to the surrounding land covers. The methods of measuring the radiation and wind fields in the woods were designed to give spatial mean values. To indicate the reduction of radiation and wind velocity by trees, three reduction coefficients; for nocturnal radiation f_r, direct solar radiation f_d and wind velocity R_v, were defined. The measured coefficients were shown as functions of the density of the trees. The changes in the coefficients due to defoliation were also shown. Regression analysis based on the measured air temperature distributions was conducted to consider the relation between the local air temperature and the surrounding land cover. The results show that a multi-variable regression model with four variables; rates of artificial earth surface, lawn and grass, wood and water surface to total area, is appropriate to explain the distributions. It also reveals that there is a size of the surrounding area for evaluation of the rates of the land cover to maximize the correlation coefficient of the regression equations. The wind direction has an affect on the air temperature distributions; namely, the composition of the wind-ward land cover is important in explaining the air temperature distributions. The wind velocity also affects the temperature distributions so that the extent of the temperature differences in the area are larger at weaker wind velocities. The wind velocity also affects the size of the surrounding land which maximizes the correlation coefficient of the regression equation. As the wind velocity increases, the size decreases. The rate of sensible heat transfer between the earth surface and air is thought to be the most important physical factor in the formation of the temperature distribution in the area. Therefore the significance of the rate of sensible heat transfer as the explanation variable for single-variable regression analysis is considered. As a result, it is a more important factor than the rate of artificial earth surface to the total area as the explanation variable for the single-variable regression analysis to explain the measured air temperature distributions.

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This paper searches for the reason for the difference between the air-conditioning load calculation by HASP/ACLD/8001 and air-conditioning energy consumption. The causes of the difference between AHET and cooling energy consumption are cooling period, whether there is package unit or fancoil unit, density of the inside illumination and draft load. The difference can be explained by these factors. And AHET is greater than the actual energy consumption. The difference between AHST and heating energy consumption is caused by the heating period, whether or not air-conditioning uses an air source or water source area of windows, total floor space and the existence of peaple. But it cannot be explained by these factors as in the case of cooling.

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The heat pump-boiler system, which is suitable for central heating plants because of its high heat utilization factor, is now under development. The system has a heat pump directly driven by a Rankine cycle steam expander and supplies both pumped up heat and Rankine cycle waste heat. In the first report, several models with different heat exchanger arrangements, heat pump cycle compression processes, and expansion processes, were proposed. Then, enthalpy and exergie analyses showed a model with the highest utilization factor. A system has been planned on the basis of this report. The plant is characterized by the introduction of a latent heat recovery heat exchanger which recovers the latent heat of the steam in the exhaust gas from the boiler, by the use of a screw type power recovery expander in place of a expansion valve in the heat pump cycle, and by the use of a screw type steam expander instead of a steam turbine. This report analyzes the influence of the efficiencies and operating conditions of the components on the heat utilization factor of the plant in order to clarify the component development targets and the system design base. The results are as followed: 1) A latent heat recovery heat exchanger is effective in increasing the heat utilization factor. The use of a heat exchanger as a boiler air pre-heater or a supply hot water heater is proposed. Analysis on the heat utilization factor showed that the former utilization factor is higher than the latter for equivalent boiler efficiency, and also showed that both utilization factors are nearly equal for an equal heat transfer area. 2) The increases in the heat utilization factor caused by an increase in the steam expander efficiency becomes higher as the expander inlet temperature rises. 3) A rise in the steam expander inlet pressure and temperature increases the heat utilization factor. 4) Decreasing the heat exchangers' terminal temperature gaps increases the heat utilization factor, but also increases the heat transfer area, especially when the temperature gaps are prescribed to be under 5K. 5) Reducting the heat capacity of the low temperature heat source decreases the heat utilization factor. Therefore, the heat capacity of a low temperature heat source should be selected by considering the increase in the pump work, in addition to the increase in the heat utilization factor.

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The results of investigations on fixture use in theaters have shown that fixture use is concentrated in the duration of entering and leaving the theater and/or intervals, and a waiting line is often produced. In these cases, the required number of fixtures is estimated to limit the length of the waiting line or waiting time. This paper explains the basic data and some conditions for fixture use of a limited use system. Under these conditions, a computer simulation was carried out and the required number of fixtures were estimated. This paper also shows the method of estimating the optimum number of fixtures by setting the service level.

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The mechanisms of smoke extinguishment by a discharging wire are studied. Theoretical equations which express the maximum charge density, the concentration dependence of extinguishing rate when new smoke generation is zero, and the coagulation rate between charged and uncharged particles in a large space are presented, and are verified experimentally. Using these results, the effects of coagulation on extinguishment when smoke is generated continuously are also analyzed.

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Stratified flows are closely associated with many actual problems, such as inversion in the atmosphere, dispersion of thermal effluents into natural water bodies, thermal stratification in lakes and reservoirs, heat storage tanks with thermally stratified flows and cooling of large air spaces. Therefore, the problems of stratified flows are an important subject of study in the fields of meteorology, limnology, and engineering. Many studies have been made on stratified flows in the above fields. Most of these studies, however, deal with the structure of turbulence in the stratified layers or mixing between the top and the bottom layer through the stratified shear layer, and there are few experimental studies dealing with mixing between the top and the bottom layer under circulation in the top layer or the bottom layer. The purpose of this experimental study is to clarify the hydrodynamic behavior of the thermally stratified layer under belt-driven circulation in the top layer of rectangular water tanks. The experimental conditions are; velocity of the water surface: 5〜20cm/s, initial depth of the thermally stratified layer: 10〜20cm, temperature difference between the top and bottom layers: 3〜12℃, and depth, length and width of the water tanks: 20〜40cm, 19.2〜80.0cm and 25〜40cm, respectively. The results of visualization of the flows in the water tanks show that mixing between the top and bottom layers occurs mainly in the sinking area of the top layer's circulation and that the other part of the stratified layer is very stable. It is also clear that the bottom layer is almost at rest. The temperature in the rectangular water tanks is uniform in the horizontal direction, but changes in the depth direction. The depth of the thermally stratified layer, which is defined as the depth where the temperature gradient is maximum, gradually descends with time due to the entrainment of the bottom layer's water into the top layer; the descent velocity of the stratified layer is constant and is determined by the densimetric Froude numbre of which the characteristic velocity, length ahd density difference are defined as the velocity of the water surface, the depth of the stratified layer and the density difference between the top and the bottom layer, respectively.

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