The radiative heat transfer coefficient is used to calculate radiative heat flux in the heat load calculation conveniently. The radiative heat transfer coefficient is treated as a constant value [4.7W/(m^2・K)] in most practical situations. However the constant radiative heat transfer coefficient is not always applicable to various conditions and may invite the inadequate heat load calculation results. In this paper, evaluation method of radiative heat transfer coefficient based on experiments and simulations was shown. The experiments were carried out in simple shaped laboratory and radiative heat transfer coefficient was evaluated. The results of the radiative heat transfer coefficients were 4.4W/(m^2・K) and 5.7W/(m^2・K) under heating condition and cooling condition respectively. Then the CFD simulations were carried out and radiative heat transfer coefficients were evaluated in the same conditions as the experiments. The evaluated values based on CFD showed good agreement with the experimental values. Therefore this paper concluded that the radiative heat transfer coefficient should not be used as a constant and should be treated appropriately in various conditions.

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The purpose of this study is to clarify energy saving effectiveness quantitatively of the cooling plant system which adopted inverter chillers, integrated cooling towers and free-cooling system, and etc. this paper describes the operation and control methods of this system and the result of the performance evaluation using the actual operation data during two years. The inverter's maximum coefficient of performance (COP) value is about 18 according to the catalog and the monthly maximum COP values of chillers and system indicated 18.2, 9.2 respectively through the measured period.

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This paper presents a numerical analysis on the effects of urban and built thermal environment improvements for a cooling system to cool the photocatalyst-coated external surfaces of buildings. The authors proposed a thermal model to predict temperature of the photocatalyst-coated surface covered with water film, and integrated the calculation algorithm into the outdoor thermal environment simulation tool developed by the authors. An urban area in the downtown of Tokyo was selected for analysis. Simulations were performed to evaluate the potential impacts of the cooling system on the outdoor and indoor thermal environment improvements in terms of surface temperature distributions, mean radiative temperature (MRT), the heat island potential (HIP), indoor air temperature and cooling load.

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While raw wooden materials emit less VOCs, i.e., toluene, xylene and so forth, it is expected that those emit large amount of terpenes such as pinene <alpha> and limonene. Considering the chemical reaction of VOC generated indoors and the ozone contained in the outdoor air brought by ventilation, reaction products, e.g., ultra fine particles and odorants, might be formed by the chemical reaction. The purpose of this study is to investigate the effects of chemical reaction between ozone and VOCs emitted from cedar wood on the perceived air quality. The olfactory panel assessed perceived air quality using odor intensity scale, acceptability scale and odor quality scale. VOCs concentrations were measured with GC/MS system. After ozone generation, the voted average odor intensity did not elevated significantly. However the percentage of dissatisfied subjects showed 50% or more after ozone generation, while it was almost 0% before ozone generation.

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Air-conditioning systems with breeze-line type outlets are frequently adopted for perimeter zones in intelligent office buildings. However, it is noted that several examinations are required for the establishment of design standards strategy on position and shape of the outlet. The purpose of this study is to establish design standards for breeze-line type air outlets adopted for perimeter zone in office buildings during summer season. In the first report we described outline of experimental for facilities and the results of the brief examination for a new air-conditioning system with breeze-line type air outlets. In this report, we measured five kinds of thermal environmental index under four kinds of experimental condition. We evaluate length and number of the breeze line outlets.

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In Japan, district heating and cooling system (DHC) is expected to be a promising system from the aspect of achieving efficient energy utilization at the district scale. DHC conserves energy due to its advantages such as the utilization of natural and unused heat sink/source and the introduction of high-efficiency equipment. Numerous studies on the advantages of DHC have been conducted in order to improve the energy saving effect from the advantages. However, so far, any verification concerning "Concentration effect", which is one of the most important advantages of DHC, has not been conducted. Concentration effect is provided by the combination of the heat demand of each building, and it is influenced by the following two elements. 1) "Demand-side parameters" Heat load profile and temperature difference of hot/cold water between supply and return. 2) "Division of heat source chillers" The number of heat source equipment and the chiller capacity ratio. In this study, sensitivity analysis which parameterizes the abovementioned elements is performed by simulation in order to reveal the relationship between energy efficiency ratio and these elements. The results would reveal some important information to improve "concentration effect". We have selected absorption chiller and boiler system DHC, which uses gas as its main energy source, as the case study. Only cooling heat source system, which energy efficiency varies widely, is verified. The simulation settings are set to the average values, and the parameters used in the sensitivity analysis are based on the measurement data of 7 existing DHC plants. The analysis results show as follows: ・Energy efficiency varies by up to 0.13 according to demand-side parameters. Further, it is proved that the equivalent full load hour of cooling load profile must be long, and temperature difference of cold water must be remained at a designed value for achieving high energy efficiency. ・Energy efficiency increases as the number of chillers becomes larger. However, its effect almost disappears when the number of chillers is over 6. The chiller capacity hardly affects energy efficiency unless the chiller capacity ratio is very simple, for example, when chillers are equally divided. ・Division of heat source equipment is not important in the case where the equivalent full load hour of cooling load profile is long, or speed variable pumps are introduced. ・In absorption chiller and boiler system, power consumption of pumps is the dominant factor which affects energy efficiency. In winter and at intermediate time when there is little cooling load, power consumption of pumps differs greatly. ・In this study, the plant without co-generation system (CGS) is verified. However, nowadays most of DHC plants tend to introduce CGS. Thus, the case of the plant with CGS must be verified.

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