A sensitivity analysis was carried out for 27 input parameters of a building energy performance simulation model. This research aims at providing useful design guidelines for architects to devote more attention to the design factors that have more influence in energy performance. The guidelines can be used in both energy-efficient designs for new buildings and effective energy retrofit for existing buildings. The simulation analysis was conducted for office buildings located in Seoul metropolitan area utilizing DOE-2.1D. The ranges of input values utilized in the analysis were set according to the practical information acquired from the survey research of existing buildings. Varying values for 27 input parameters, magnitude of affected output values was scrutinized and subsequent sensitivity coefficients were derived. Two types of input parameters, i.e., building design parameters and building operation parameters, were distinguished for heating and cooling loads.

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When thinking about building material surface, the results from spectrum characteristics is mainly affected by the nature of material, but considering the nature of the spectrum (the wavelength characteristic) it seems more influential. Recently, using a spectrum photometer, Naruse et.al. 2000: a. measured the spectrum reflectivity of building materials (metals and so on), b. examined the change of the characteristic of separation of surface roughness in a comparative nature, and c. measured the reflectivity of the material which is different in the surface shape. The aim of this study is to examine the roughness of the polish used on the building material surface, and measure the absorptivity behind the coat (the reflection paint, the general paint and so on) which is different from the building material surface. It gives detailed analyzes of the reflectivity of each material and a thorough examination was carried out. The results give a clear picture on the difference of the spectrum reflection and the heat income and expenditure. Through this paper the following points are clarified as part of this study, 1) Polishing number and spectrum reflectivity: Aluminum reflectivity declines as wavelength decreases proportional with the decrease in the number of polish. Similarly, reflectivity increases as wavelength increases proportional to the criteria of unpolished surface. Thus spectrum reflectivity is proportional to the wavelength and polish number. 2) Polishing number and sun radiant reflectivity: As the polishing number increases for various samples (e.g. copper, brass, acrylic fiber, stainless steel), sun radiant reflectivity decreases. Aluminum and duralumin too exhibit similar tendency, but when the polishing number increases (〜100 times), sun light reflectivity rather increased contrarily. 3) Radiation measurements in a laboratory: When mean radiant temperature is lower than building material surface temperature, the one with smaller reflectivity of polish of aluminum board exhibits the maximum radiation quantity without polish. Similarly for reflective paint, the heat loss from surface is bigger for the one with lower reflectivity. 4) Temperature effect of various surface paint materials on exposure to sunlight: Surface temperature of aluminum materials rose to different levels when coated with typical paint, polished, unpolished and high reflected paint. Aluminum surface when painted with typical paint shaved high temperature when exposed to sunlight followed by polished surface and the unpolished surface. The material coated with high reflected painted showed the lowest rise of surface temperature. It was possible to ascertain that it became high when sun radiant absorptivity of shortwave length area became large. 5) Emissivity and surface temperature: When mean radiant temperature was lower for the building material surface, the surface temperature became a little low in response to the small emissivity in long wave length areas. 6) A wavelength characteristic with various spectrum reflectivity was calculated as the difference of sun radiant absorptivity and emissivity of roughness of the surface of the building material surface. It was found to be related with the rise of surface temperature and difference with radiation quantity, as experimentally shown.

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It is shown that the ratio of small building, 3,000 square meters or less, is large in Japan. Using the design of experiment, formulae of annual thermal load of small building were prepared. As a result, it was clarified that annual thermal load, especially heating load, of small building is larger than that of large building, that the amount of saving heating load by building design and site plan is much larger than cooling load, and that the amount in small building is larger than large building.

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This paper describes characteristics of the annual domestic energy consumption measured on ten houses in a cold climate region. First of all, it was found that the amounts of annual energy consumption ranged from 358.2MJ/m^2 to 1006.5MJ/m^2, and that the mean value was 674.4MJ/m^2. Secondly, the breakdown of electric power consumption of typical electrical appliances in each of the houses was shown and it was clarified that standby power use reached 12.1% of the total amount of electric power consumption. In addition, characteristics of seasonal and time fluctuation of domestic demand for each energy use were presented. The energy consumption for heating was greatly reduced comparing with the results obtained by previous survey.

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In order to reduce energy consumption, we designed and build an office building with natural ventilation and night purge system in Tokyo, and tried to evaluate energy conservation effects of this building. First, we evaluated the effects by numerical analysis at planning stage. The results of analysis indicated that it is possible to reduce about 60% of daily energy consumption for air-conditioning system in an intermediate period by using natural ventilation and night purge system. Especially, when the air-conditioning system started, it is able to reduce air-conditioning load by the effect of cool thermal storage by night purge. Next, we carried out measurements in this building at the operating. From the results of measurements, the energy conservation effects were able to be confirmed almost the same of that of numerical analysis. In addition, the amount of energy reduction by natural utilization system including the directly cooling system by outdoor air, possibly equal to 80% of daily air-conditioning load. Those results show that the natural utilization system is very effective for energy saving.

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Three-dimensional free surface flow analysis with VOF method (numerical computation) was used to examine the free oscillation flow of seal water in the model trap with rectangular sections, which its partition wall thickness and the ratio of cross sectional area ratio of legs have been changed from the standard dimension. Subsequently, we compared the numerical result with the experimental results and obtained a positive agreement. Also, we gained the basic knowledge on the evaluation method for natural frequency, an important attributes of induced siphon, by studying it with the internal flow attribute of seal water in the model trap.

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A field measurement on 5 familial and 3 single dwellings during summer Y2K leads to obtain both getting start probability of air conditioning system vs. indoor globe temperature and operating probability of air conditioning vs. outdoor temperature, which are deeply relevant to transition probabilities of the state Off-to-On and On-to-Off respectively. Getting these state transition probabilities is seemed to be a great first step to the way applying the Markov Model to ON/OFF state analysis for air conditioning system. But it is also significant to predict more precise schedule of air conditioning operation than conventional method, where both the schedule of air conditioning operation and inhabitants occupancy are dealt with wholly. Using obtained state transition probabilities allows you to discriminate real schedule of air conditioning operation from inhabitant occupancy schedule.

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Uniform outlet duct systems are used widely in the industrial field of air-conditioning, factory ventilation and others. A damper is usually arranged at each branch duct and adjusted to have designed flux discharge. In uniform outlet duct systems, the flow distribution at outlets would become more uniform when the ratio of the total sectional areas of the branch ducts to that of the main duct get smaller. Above consideration suggests we can get equal discharge at every outlet without adding any resistance for control at branch ducts if the area ratio is chosen suitably. So, it is considered that a uniform distribution can be realized without adding control resistance to the branch duct if the area ratio is chosen suitably. Based on this idea, precise flow analysis including dividing pressure losses at each branch was done to consider relations between the area ratio M_L (= total sum of sectional area of each branch duct/sectional area of main duct) and flow distributions. Result of flow analysis clarified the following points: 1. Influence of the main duct dividing loss on flow distributions is small. 2. Influence of the branch duct dividing loss on flow distributions is very large. 3. when the amount of length/diameter of main duct L/D is less than 100, the maximum outlet part is in the end part of the main duct and when L/D becomes larger than 100, that moves to the root part of the main duct. 4. Result of flow analysis in this study dose not show the phenomena pointed out by D.S. Miller in which outlet is maximum at the middle part of main duct when the length of main duct is in medium range and M_L>1.0. And we clarified the design conditions in which the flow distributions at outlets came uniform. 1) M_L is between 0.8 and 1.2 when the deviation of the flow distribution at the uniform outlet δ V is 5%. 2) The total pressure needed is decided by M_L uniquely. Based on those results, new design method using the area ratio M_L is proposed in this study.

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This study was conducted focusing on housing environment of elderly people and their safety in winter season. Effect of temperature and humidity measurement and data feedback to the elderly people was monitored. The following three points were confirmed; (1) Elderly people and their family recognized measured information of their housing environment repeatedly. As the result, they confirmed the difference between their thermal sensation and measured temperature in winter. They also found the risk of health in low temperature at home. (2) Their consciousness of indoor environment made better usage of housing service facility. This led the reduction of fear on health and accident at home. (3) Handling of these indoor environment informations with multimedia equipment made closer communication between elderly people and their family who live far from them.

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In planning an air conditioning system with an ice storage unit, the effective utilization of low temperature energy is an important factor from the viewpoint of cost reduction. For example, lower temperature supply water and air reduce the coefficient of performance of a refrigeration machine, and increase the thickness of heat insulation material. However, they enable larger temperature differences, and reduce equipment sizes and power demand. It is an important subject to evaluate the effect of the supply water and air temperatures on the long-term economics by considering the operation of an ice storage unit. The purposes of this paper are to propose an optimal operational planning method for an air conditioning system with an ice storage unit, and to analyze the effect through a numerical study for an office building. The results are summarized as follows: 1) In the case of the ice storage system, annual demand and energy charges are reduced by about 40% by the utilization of the economical electric power during night. In addition, they are reduced by about 60% by the utilization of lower temperature supply water and air. 2) The utilization of lower temperature supply water and air in the air conditioning system with the ice storage system is effective for the annual total cost, and the influence of supply air temperature is larger than that of supply water temperature on the long-term economics. 3) The utilization of lower temperature supply air is effective for annual energy charge, and the power consumption of the air handling unit is reduced by about 45% in comparison with the case of conventional supply water and air temperatures. 4) The annual total cost is reduced as the ice storage unit capacity decreases. Reversely, the annual energy charge is reduced as the ice storage unit capacity increases.

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This study is to analyze the performance of a radiation-panel cooling system by means of CFD. Since the surface temperature of the radiation-panel analyzed in this study can be controlled under the dew-point temperature, we can expect the system to be energy saving and dehumidifying. In the first step of this study, the indoor thermal environment of the office space, which is air-conditioned by radiation-panel cooling system, is analyzed by field measurement and CFD (coupled simulation of convection and radiation). With comparing the both results, the validity of the CFD method is examined from the practical point of view. In the next step, the thermal environment of the model office space, which is cooled by tree types of HVAC system (radiation-panel cooling system, all-air cooling system, and hybrid air-cooling system of radiation-panel and natural ventilation), is analyzed by CFD. Installing a human model in the room model, the characteristics of heat transfer from human are also analyzed. In the case of the radiation-panel cooling system, operative temperature and MRT of the human model become lower than those in all-air cooling system. The radiation-panel cooling system is concluded as very energy-efficient in this study.

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This study is to evaluate the horizontal drain pipe system equipped with exclusive header piping for SI housing and propose the design method. In this paper, both single fixture drain and plural fixture drain were carried out by using a model piping (with a length of 7〜11m) to compare the performance of this system with conventional drain system, and the features of this system was obtained. The authors describe the knowledges obtained from the perfomance evaluation experiment, using the characteristic of fixture discharge, the pressure in pipe/trap seal water lost, and the flow velocity in pipe/carrying performance as an evaluation index.

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The energy required in the hot water supply system is determined by how many degrees the water temperature is raised to meet a given hot water supply temperature. Therefore, the hot water supply temperature constitutes an important factor in considering energy conservation in the hot water supply system. In this report we measured water temperatures at purification facilities in 9 major cities in Japan, conducted correlation analysis in relation to air temperature, and established regression equations to predict water temperature from air temperature. A prediction method of water temperature is indicated based on the calculation models for two separate water passages: one from the source of rivers to purification facilities, the other from purification facilities to distribution pipes.

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