This study deals with the thermal performance of horizontal earth coil heat exchangers. There are four types of earth coils which were made of polyethylene pipes. Each type of them was buried into the depth from 1.0m to 1.8m and the length of 5.0m, respectively. Three types of them are the spiral coils and their diameters are 0.8m. The pitch of two spiral coils is 0.2m. And pitch of the third one is 0.4m. The last type of the earth coil used in the experiment is consisted of horizontal laid pipes in six rows. Experiments on the heat extraction from the soil utilizing four types of coils have been continued for two years. During first year of the experiment, the heat extraction rates of each type of coils were examined. Results showed that there was not so big difference of heat extraction rate among those four types which were buried into the same size of soil. The capability of the seasonal heat extraction utilizing the horizontal coil was confirmed. The soil temperatures around the earth coils were recovered to the natural temperature of the soil till the beginning of next winter. During the second year, the experiment of the heating, utilizing heat pump system connected to the earth coils, was conducted. The heating load, used for the experiment, was calculated by HASP code as a demand of the typical one family house. The result of the average temperature of the working fluid in the coil was -1.6℃ during five months experimental period. Although, the average temperature of heat extraction was lower than the average outdoor temperature in winter, a higher C.O.P. value of the ground-coupled heat pump system, compared to the air source heat pump system, has been obtained. The average C.O.P. of the present system in the winter was 2.38 constantly during the experiment.

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Experimental study on the heat loss from vertical drainage stack, through which some amount of hot water is drained, is conducted in a laboratory. Effects of some factors, such as total volume and flow rate of drained water, pipe length, material of pipe, on the heat loss are investigated. To estimate the heat loss, an analytical model is proposed. It uses the steady falling-film theory and the unsteady thermal conduction equation in pipe wall. It was shown that the heat losses predicted by the simplified analytical model are nearly equal to the experimental ones. A set of numerical experiments using the analytical model is conducted according to design experiment theory. Some significant factors which influence the heat loss are clarified and quantitative effects of each factor on the heat loss are expressed in the form of simple regression equations. These equations are useful to evaluate the energy saving design of drain pipe system. Moreover heat loss from the vertical drainage stack is compared with that from the horizontal drain pipe, which is discussed in the previous paper by the authors. It was shown that the former is greater than the later.

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In this paper, calculation methods used in a simulation code "SCIENCE" are introduced focussing on conjugate heat transfer between room walls and indoor air flows. SCIENCE is a CFD code developed by authors and applicable to calculations of room air flow and temperature distributions as well as thermal comfort index ones. As for the conjugate heat transfer, two calculation procedures are introduced. HMM (Harmonic Mean Method) is a simple method to treat heat transfer at fluid-solid interfaces although a coefficient should be determined with some empirical procedures. HBM (Heat Balance equation Method) is a more widely applicable method including radiative heat exchanges between walls. A direct simulation method is introduced to calculate shape factors between finite areas of wall surfaces. To treat transient heat transfer through walls, two methods are presented. One is an analytical method assuming semi-infinite wall thickness and the other is a method applying thermal response factors of walls.

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In the previous report, monthly weather data at more than 3700 locations throughout the world were compiled for air-conditioning load calculation (see Part 1), and methods for estimating hourly weather values based on monthly data were proposed (see Part 2). In this report, a periodical steady state calculation system was developed for estimating design and average heat loads at any location in the world. We conducted many case studies on office buildings in six Japanese cities for which Standard Weather Data had been prepared, and compared values calculated using the conventional Standard Weather Data to those calculated using our new system. For both design heat load and average heat load the differences were less than 10%, indicating that our new system is suitable for practical use. Also, system modifications that must be done in order to prepare the system for use outside Japan were identified.

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In the previous paper, three types of cooling systems are examined, i.e. panel cooling only, cooling air supply only and combination of cooling air and cooling panel. The combination of cooling jet and cooling panel is proved to be the most promising system from the view point of reducing down draft and minimizing the effect of large heat load from the window. In this paper, the authors experimentally examine the influences of the following parameters on the air and thermal environment of a room model which is air-conditioned by the combination of cooling jet and cooling panel; (1) position and capacity of cooling panel, (2) supplying and exhausting conditions. The result of model experiment shows that floor cooling panel system causes strong vertical temperature distribution, and uneven radiative environment comparing the cooling panel on ceiling system. Reducing the temperature difference between the exhaust and supply air and decreasing the cooling panel surface temperature is effective for reducing the down draft risk in an occupied zone. In this case temperature distribution in the room become more uniform and the supply jet does not descend and mixed with the warm air from the window. The position of exhaust inlet have an important effect upon occupied zone temperature. When the exhaust opening is set above the window, the upstream heated by the wind is directly exhausted without diffusion and thus the heat load from the window has small influence on the thermal environment of the room.

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In the past, the energy system in a building and group of buildings was determined mainly on the basis of economical rationality on the side of consumers, but the present research has helped to clarify the concept of "energy management". It has been attempted to establish this concept as a practical business method for constructing an energy system aimed at effective use of energy and natural resources, that is, their saving and increasing economical effects. Also, this concept premises a "unified energy system" by coordinating the consumer side with the supplier side, as well as considering the special characteristics of various types of energy supplied to buildings. This report presents the construction method of energy-system unification based on energy management, discusses cases of urban development projects and clarifies the validity of the best mixed system.

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The purpose of this study is to suggest the calculating methods for the loads and capacity of a storage tank of hot water supply systems in dwelling houses. The authors analyzed the usage in each fixture of the hot water supply systems on the basis of the data which had been measured in five dwelling houses for one or two years. These contents are as follows; frequency, duration time, discharge flow rate used in the hot water supply systems. The hot water temperature used in each facility has been shown in the paper of part 1. The models for calculation of the loads in hot water supply systems were prepared on the basis of these analysis. The models were considered on the effects of the number of flats, because the frequency of hot water uses in each fixture per flat is gradually reduced according to increase of the number of flats. As for the calculating method of hot water consumption, Monte Carlo Simulation was adopted. This paper showed the results of hot water consumption calculated in each interval of time through a day. The relationships between the volume of hot water consumption per flat and the number of flats were clarified. Also, the relationships between the instantaneous maximum flow rates and the fixture units in each hot water facility were analyzed using the same method that had been suggested for cold water supply systems by S. MURAKAWA. On the basis of the hot water flow rates calculated for 24 hours, the capacity of a storage tank and heater was analyzed using a simulation method. A calculating method for the capacity of a storage tank and heater was suggested to alter the existing method.

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This paper describes the single-sided ventilation characteristics in rectangular spaces which are constructed aside an airway. The experiments were carried out using small models of rectangular spaces. The methane was flowed out from the center at the end surface of each space using a gas flow system controlled by a computer. The distributions of the gas concentration and the ventilation characteristics, such as age-of-air, amount of ventilation air and air-exchange rate of the spaces, were measured for the spaces with various aspect-ratios, D/W, where D is depth and W is inlet width along the airway. The summary of the present experiments is as follows: 1) The ventilated space of each shape is roughly classified into three regions based on the results of the observations using tuft, the distributions of averaged and r.m.s. values of gas concentration that are affected by the ventilation flow with three dimensional structure (see Figs. 5 and 7). 2) The amount of ventilation air or ventilation efficiency, Q_v, is roughly proportional to the inlet width W of the spaces. Its relationship between Q_v and W is expressed as Eq. (4). However, the amount of ventilation air of the square shape is considerably large compared with that of other shapes. 3) The air-exchange rate, N, is roughly inverse proportion to the depth D under a constant inlet width W. Its relationship between N and D is expressed as Eq. (6). 4) For the spaces with square shape, ventilation flow from the airway is circulated within the whole of the space. The gas is well diffused by this recirculated ventilation flow. 5) For the spaces with shallow shapes (D<0.7W), the ventilation flow is circulated mainly within the downstream region of the space, then the gas is convective-diffused within the upper stream region. 6) For the spaces with deep shapes (D>1.5W), the gas concentration keeps relatively high level in the interior region near the end-surface except the inlet region of the space in which the ventilation flow is circulated.

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In order to investigate the shape of a pipe fitting with small energy loss, the flow mechanism in a pipe fitting with branching angle θ_p of 45°and with the sharp edged lateral entrance was studied theoretically and experimentally for laminar flow. The area ratio m was chosen to be equal to 2.0, 3.0 and 4.0. The ratio of lateral discharge to total discharge Q_2/Q_1 was regulated at several values between 0.0 and 1.0. In the experiment, the Reynolds number defined at the upstream section of the main conduit R_<e1> covered a range between 500 and 2000. The conclusions can be summarized as follows: 1) To study the flow mechanism in a pipe fitting the flow was analyzed by the free-streamline theory. The coefficient of contraction in the lateral conduit C_c for θ_p of 45° is greater than that of 90° when m and Q_2/Q_1 are the same values. The streamline was calculated. 2) The separation point on the wall of the main conduit was analyzed by the methods according to Prandtl and Tani for Laminar flow. 3) The flow field in the real pipe fitting with rectangular cross section was studied by the flow visualization technique. The secondary flow occurs in the lateral conduit and the downstream section of the main conduit. The separations of flow occur from the upstream corner of the lateral entrance and on the wall of the main conduit. The separation point on the wall of the main conduit is characterized by such parameters as m, R_<e1>, Q_2/Q_1 and l_<1d>/h_1 where l_<1d> and h_1 are the length and the width of the upstream section of the main conduit, respectively. 4) The results obtained by the theoretical analysis and experiment coincide fairly well.

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Heat pump systems utilizing ambient air as a heat source are widely used; however, in the case of using conventional tube banks as an evaporator, moisture in humid air freezes and forms the frost layer on tube surface, which produces a decrease in heat transfer, an increase in pressure loss, and finally choking of the evaporators. High performance heat exchanger can be expected by applying an impinging jet having high heat-transfer characteristics for the conventional tube-bank heat exchanger. In order to utilizing the impinging-jet tube-bank heat exchanger in an environment where the above-mentioned frost formation is unavoidable, the heat-transfer and frosting characteristics of a cooled tube in an impinging jet must be clarified. In the present report, a comparison is made between heat transfer of a tube in an uniform flow and that in an impinging jet, and then the possibility of improving the performance of tube-bank heat exchanger by utilizing the impinging jet is shown. After that the local heat-transfer characteristics of a cooled tube in an air impinging jet and the influence of frosting on them are analyzed in an intensive experiment. The results obtained in the present report are as follows; (1) The heat transfer of a heated tube in an impinging jet is much higher than that in a uniform flow when they are compared at the same superficial velocity. (2) The transient frost-layer thickness, local heat-transfer coefficient, and the circumferential distribution of overall local Nusselt number were clarified. (3) In the test conditions applied in the present study, the heat transfer of a frosted tube is less than that of the heated tubes because the effect of the increase of thermal resistance due to the frost layer is dominant as compared with the effects of the latent-heat release and increase of heat-transfer area due to frosting. (4) Finally the ratio of the convection thermal resistance between the surface of the frost layer and air flow to the total thermal resistance between tube surface and air flow including that of frost layer was obtained and shown by an empirical formula as a function of time and temperature difference between inlet air and tube surface.

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This paper presents estimation and evaluation on utilization of the "unused heat energy" in the whole region of Nagoya according to the results of the preceding paper. The respective estimations were conducted for the five cases shown in the preceding paper. Consequently the estimations predict that utilization of the "unused thermal energy" will reduce the whole primary energy consumption in all the buildings by 6%. The evaluation shows that the energy reduction is comparable to the one that is estimated if solar hot water supply system, which has one thirtieth of floor area in collector area, is put in every residential building. But the energy reduction is not evaluated to be small, because the "unused thermal energy" does not exist everywhere in the actual city while the solar energy is available throughout. Thus it is concluded that the utilization of unused thermal energy does not have potential for an ace to save energy in urban regions, but that it will certainly become one of effective mehods for saving energy if it is adopted in urban regions having dense heat demands.

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The purpose of this study is to find out the design requirements of the shower devices with which users can take a shower with comfortable conditions and energy conservation, and to propose the test methods for performance of spray of shower heads according to the experiments on the hydraulics and sensuous evaluation of users. The hydraulic experiment like the Part 1 was carried out on the shower heads that were attached with the spray plates of fourteen types changing the number and size of the holes. The hydraulic characteristics of the shower heads of each spray type were clarified. In succession, two kinds of experiment were carried out to get the sensuous evaluations of users for taking a shower. At first, the subjects, sixteen graduate students of Hiroshima University, adjusted the shower flow rates according to three levels; suitable, slightly high and slightly low. Ten types of the spray plates and five kinds of shower heads used at Part 1 were selected for the experiment. The temperature of hot water was supplied at 42℃. As the results, the authors clarified the suitable flow rates on winter and summer seasons, the hydraulic pressure of spray on the received surface, the range of the coefficients of hydraulic pressure as the pleasant feeling and so on. Next, the same subjects took a shower in daily style. Six types of the spray plates were selected from the experiment mentioned above. The temperature, the flow rates and the volumes of hot water usage were analyzed on the basis of the measuring results. From these results, the authors suggested the preference shower heads from the view points of energy conservation and comfortable uses, and showed the temperature and the flow rate for the design requirements of hot water supply systems.

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There have been increasing demands for a better thermal environment in air-conditioned spaces recently. The calculation of radiative heat transfer is indispensable in estimating the thermal comfort of an indoor environment, but conventional methods are not easily applicable to real living spaces because of furnitures placed and required accuracy for estimating human thermal sensation. This paper describes an improved numerical method for the analysis of radiative heat transfer that is proposed to calculate accurately for complicated geometry with reasonable computational time. We have proposed several methods that use fewer emitted rays for simulating radiative energy, and we have evaluated their performance by executing model calculations. As the result, the method of distributing emitting points by staggering allocated square patches shows the best performance and it makes possible the calculation about two times as fast as the conventional method. We have also considered to apply the method to the numerical flow analysis by using a rough mesh generated from a mesh for fluid calculation. The example calculations for an air-conditioning system which uses thermal radiation panels have been carried out to demonstrate the ability of the present method.

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In the previous paper, the fundamental characteristics of indoor thermal environment in an air-conditioned room with the combination of cooling jet and cooling panel were examined. In this paper, the authors experimentally examine the influence of obstacles in the room such as a bed, a blind with thermal insulation etc. The bed arranged within a stagnant air region has little influence on the airflow and air temperature distribution in the room. However it has effect on the surface temperature distribution of the floor. The blind with thermal insulation has great effect of reducing the heat radiation from the window. Then, another two types of cooling systems are tested. Both system has no active cooling system for the ceiling. The ceiling is cooled passively by the supplied air with wall jet type. In one type, a supply outlet is installed at the center of the ceiling, and supply air is ejected horizontally and adheres the ceiling. In the second type, a slot supply outlet is installed at the corner between the ceiling and the wall. The latter system is rather efficient for radiative cooling by the passively cooled ceiling.

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Insulation of clothing has a great influence on the thermal characteristics of a human body. Examination of the influence takes an important role in improving thermal comfort and energy consumption of air conditioners. Our report describes the experimental study of insulation effect of clothing for thermal characteristics of a human body in its segments. The experiments were performed using one young male subject in a climate chamber. The physiological tests were conducted on the sitting subject dressed in 0.17clo and 0.57clo. The environmental conditions in the present experiments were: chamber air temperature≒28℃, mean radiant temperature is approximately equal to chamber air temperature, relative humidity≒52%, and air relocity≒0.15m/s (still air movement). The measuring items were: skin temperatures, heat flux from skin surfaces, local air velocities near skin surfaces, and temperatures and relative humidities within the clothing at selected segments of the body (Hardy-DuBois' twelve sites). The results obtained from the present study are as follows: 1. as the insulation of the clothing increases, 1) the increase of skin temperatures appears clearly in the peripheral segments of body, such as shin, calf, and instep. 2) the decrease of heat flux from skin surfaces appears significantly in the trunk segments of body, such as chest and abdomen. 3) the increase of temperatures within the clothing becomes clearly in the peripheral segments of body, such as shin, calf, and instep. Further the increase of absolute humidities within the clothing appears clearly in chest, abdomen, and instep. 2. assuming that the activity level is 1.0met, the calculated results of the average skin temperature and the heat flux from the whole skin surface using the experimental results agree qualitatively with the theoretical results obtained from the 2-node model developed by Gagge et al. However, as the insulation of the clothing increases, the experimental result about the increase of the average skin temperature exceeds the theoretical result by about 0.4℃. And the experimental result of the heat flux from the whole skin surface exceeds the theoretical result by about 30%.

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This paper focuses on the characteristics of actual water consumption and operating conditions for each process of the wastewater reuse system in the local area. In order to obtain basic data for the water balance and optimization of the treatment facility in the stage of design and maintenance, we investigated and analyzed in advance on the following: hourly city water and reclaimed water consumpition and its balance; the behavior of water levels in the flow equalization tank and the reclaimed water receiving tank; the control of the flow rate for reclaimed water to be treated in order to achieve a balance of supply and demand for the water, etc. We surveyed the amount and pattern of water consumption and the ratio of water savings in the categories of purpose of use, use in individual buildings, as well as the entire region. The fluctuation of hourly water levels in the flow equalization tank and the reclaimed water receiving tank were estimated by the simulation of water balance-pollutant load calculation program. At the same time, the amount of the excess reclaimed water, the make-up water added to the reclaimed water and its time were predicted. In this study, we obtained the basic data for the design and established the method of prediction for the water balance and operation conditions.

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