Annual energy consumption for air conditioning and dynamic behaviors of room temperature and humidity, are calculated by computer simulation program on office building models having standard structures and standard air conditioning systems. Its total floor space is about 13000m^2 and this building is considered average grade. The characteristics of energy consumption and its influence on room thermal environments are firstly analyzed in the case of this standard model by "The Chart of Effective Analysis for Energy Conservation". This chart is newly proposed and it expedites to analyze the seasonal energy consumption in both aspects of the absolute quantity and the coefficient of energy consumption for air conditioning, CEC. Secondarily, considerations are given to the influence of regional weather characteristics and the effect of energy saving factors which is determined at the planning stage, on energy consumption and thermal environments, too. Superiority and inconsistency of CEC as an efficiency index become clear in this study on components of CEC, that is, CEC of heat source equipments and CEC of pumps and fans.

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Many studies have been made on the prediction of the behaviour of thermal effluents into the seas, lakes, and rivers. These studies are classified into two groups: one is experimental study and the other is numerical study. The first to fourth report of this study belong to the former. Through these studies the authors clarified the influence of some dominant nondimensional factors, that is, densimetric Froude number etc., on the behaviour of thermal effluents into rectangular open channels. In experimental studies, however, two difficult problems are always encountered. One is that it takes a large amount of money and time to make the experimental apparatus, and the other is the problem of scale effects. On the other hand, the performance of the digital computer has increased remarkably in both computation speed and memory capacity in the last five years and they are now easier and cheaper to use than in previous years. This paper investigates the applicability of SIMPLE (Semi-Implicit Method for Pressure-Linked Equations) to a flow field in a rectangular open channel into which thermal effluent is discharged from a rectangular conduit in a side wall of the channel. At first we investigated the influence of the standard of convergence judgement by the ADI method, distances between meshes, and boundary conditions for velocity v in the main flow direction at the thermal effluent outlet, on the accuracy of numerical calculations. It was clarified that the boundary condition for the velocity v at the outlet of the thermal effluent should be taken as free slip rather than no slip. The computated and experimental results were compared to investigate the total accuracy of SIMPLE. The computational and experimental conditions are; width of the channel: 20cm, depth of the channel: 10cm, dimensions of the rectangular conduit: 5cm×2cm, depth of the center of conduit: 5cm, temperature of thermal effluent: 41.0℃, ambient water temperature: 26.1℃, flow rate of the channel: 78.5l/min, flow rate of thermal effluent: 4.5l/min. The calculated thermal distribution, reduction of maximum temperature in the main flow direction, areas in the isothermal lines, and volumes in the isothermal contours agreed well with experimental results, thus clarifying that SIMPLE is applicable to the above flow field. To verify the general applicability of this numerical calculation method to the above flow field, however, more calculations under various conditions are necessary. We intend to continue to study this point and report the results in the next paper.

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In the last ten years, the performance of digital computers has been improved remarkably in both computation speed and memory capacity. With the advances in digital computers, the role of numerical calculations has become more and more important in the prediction of the behavior of warm water flowing into rivers, lakes, seas, etc., as in many other important fields of engineering. The previous study showed that SIMPLE (Semi-Implicit Method for Pressure Linked Equations) was available for predicting the behavior of warm water discharged into a rectangular open channel. The accuracy of calculation, however, was examined under only one discharge condition of warm water. Therefore whether SIMPLE is sufficient under other discharge conditions is a matter for argument. This paper investigates the applicability of SIMPLE to the flow fields in a rectangular open channel where warm water is discharged under various discharge conditions from a rectangular conduit in the side wall of the channel. Eight different computational and experimental conditions were chosen to make different non-isothermal flow fields which include surface discharges, submerged discharges, and discharges with strong or weak buoyancy. Experiments were performed for temperature measurement and to visualize the thermal dispersions of warm water in the channel before the numerical calculations were made. The computed thermal distributions, reduction of maximum temperature in the main flow direction, areas surrounded by isothermal lines, and volumes surrounded by isothermal surfaces were compared with the experimental results to investigate the accuracy of calculations with SIMPLE. The main results of this study are: SIMPLE is an excellent numerical method for predicting the behaviors of warm water flows into a rectangular open channel under the condition that the warm water is discharged from the submerged conduit with weak buoyancy. However, when warm water is discharged with very strong buoyancy, or is discharged near the surface of the channel water, discrepancies between computed results and experimental results appear in the reduction of maximum temperature and thermal distributions near the water surface. It is assumed that these discrepancies are mainly caused by two factors. One is that the mumerical calculations were carried out at insufficiently fine distances between meshes because of economical restriction. The other is that the flow in the horizontal direction caused by the water surface gradient is not included in the calculation. More detailed investigation into the causes of these discrepancies and improvement of the present method are necessary. The applicability of SIMPLE to warm water flows into real rivers must be also investigated.

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This paper presents numerical predictions of the characteristics of swirl air-outlet diffusers. A simplified model of diffusers is introduced to treat this problem as axisymmetric flows. It is assumed that the flows are laminar and the ratio of the secondary air flow rate to that of the primary air are the given conditions. At the inlet boundary some assumptions are also made to relate the swirl ratio to the geometrical factors of diffusers. The basic equations describing the problem are elliptic type differential equations and have a similar form for three variables; vorticity, stream function and tangential velocity. Finite difference equations with an upwind difference scheme for convection terms are solved by the point successive over-relaxation method together with appropriate boundary conditions. Non-uniform grid spacing is used in these calculations and to avoid divergence relaxation factors of the vorticity are set between 0.5 and 1.0. To calculate pressure fields, basic equations written in primitive forms are directly integrated along appropriately determined paths. The flow patterns inside diffusers are calculated first, then they are used to predict the characteristics of diffusers. Predictions show a tendency qualitatively similar with previously published experimental data.

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None of the present heating and cooling load simulation procedures take into account the absorption and desorption of moisture by the structure and interior furnishings of a building. This paper describes a procedure which simulates the absorption and desorption processes of building components. This procedure is based on the response factor method presented by Mitalas and Stephenson. However, the response factors used in this paper are extended to be surface heat or moisture flux responses against the unit triangle pulse of the air temperature or absolute humidity. There are 16 kinds of response factors in both heat and moisture flux through walls. They are considered to be 8 response factors for each flux at the 1) outside surface for outside air temperature excitation 2) outside surface for outside air specific humidity excitation 3) outside surface for inside air temperature excitation 4) outside surface for inside air specific humidity excitation 5) inside surface for outside air temperature excitation 6) inside surface for outside air specifi chumidity excitation 7) inside surface for inside air temperature excitation 8) inside surface for inside air specific humidity excitation The factors are calculated by solving the Crank-Nicolson difference equations with heat and moisture transfer in the hygroscopic region presented by Maeda. The algorithm for calculating heat and moisture gain, space cooling load, heat and moisture extraction, and room air temperature and humidity is also discussed. The temperature and humidity predicted by this algorithm show good agreement with the values measured in an ALC test room.

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Air conditioning systems have many heat exchangers. The cooling coils in the air-handling units, the heart of the heat exchanger, are most important. We developed computer programs to accurately calculate the heat transfer characteristics of cooling coils, and analyze the affect of cooling coils on air conditioning systems by many computer simulation outputs. The calculation procedure is as follows; The cooling coil is divided into 30〜50 sections and the heat and mass balance lead to simultaneous equations in one section. Since it is not easy to solve these equations, the trial and error method is used. The equations are solved from the lower reaches section of the water flow to the higher reaches section, and the final coil outlet temperature of the water and the coil outlet temperature and humidity of the chilled air are calculated by the Newton-Raphson method as a computer technique. In the next stage, the effect of the design parameters (water velocity, inlet water temperature, air velocity, row) on heat transfer is considered by analyzing many outputs. The original chart is presented for analysis of the characteristics of system control.

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In thermally stratified low-Reynolds number turbulent flows, the thermocline, where temperature changes steeply, is so stable that the transport of momentum, mass, and heat through this layer is extremely limited. Flows of this type are seen in the circulation flow driven by wind stress in the upper layer of stratified bays or lakes, flow in a stratified-type heat storage water tank, etc.. A number of researches on this type of flow have been made in many fields of science and engineering, such as meteorology, civil engineering, architecture, chemical engineering, etc.. The purpose of this paper is to establish a numerical computing method of analyzing thermally stratified low-Reynolds number turbulent flows. The authors tried to numerically compute the behavior of the thermocline in a rectanguler cavity when the upper layer is circulating. In this paper, a k-ε two-equations model is used to organize a set of equations describing the properties of turbulence. However, when this model is applied to the above mentioned flow, first the following technique must be adopted because the water in the cavity is initially at rest. 1) At the early stage of computation, where laminar flow is dominant, the program needs to be executed with both k and ε equal to zero. Then, initial values are given to k and ε when the circulation flow develops to some extent, that is to say, computation for turbulent flows is started. Secondly, we take the following modification. 2) The value of the coefficient c_2 in ε-equation should be changed from 1.92, which is recommended by Launder et al., to 1.7. The above mentioned techniques make it possible to apply a k-ε model to thermally stratified low-Reynolds number turbulent flows. The authors then tried computation under three conditions having different densimetric Froud numbers, and compared the results with the experimental results under the same conditions. The computed results agree well with the experimental results: the patterns of circulation flow; the changes of temperature distribution with time.

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While few reports have been made on the energy consumption required for air-conditioning, the general energy consumption of office buildings in Tokyo, Nagoya, etc. has already been reported. As a part of electricity consumption, we added air-conditioning to the items of the former investigations and studied office buildings in Fukuoka. Based on the investigation data, regression equations of monthly energy consumption for air-conditioning are found to correspond to changes in weather. The results are as follows: 1) The annual variation of total energy consumption showed the same tendency as that of the outside weather. 2) The regression equations, which were led with respect to the properties of buildings and monthly average outside temperature, based on the energy consumption for air-conditioning in 1979, proved to be amply responsive to weather changes. 3) The changes in cooling heat source energy consumption suggested an adequate correlation with the changes in the outside temperature rather than with that of enthalpy. 4) During the period from January 1972 to December 1981, total energy consumption showed a small decrease. Since three factors of weather did not show this tendency, it may be attributed to energy conservation.

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