Thermal storage systems used in a building HVAC system can increase electrical power plant efficiency by flattening daily electricity demand consumption. Therefore it is considered to be an important technology for energy conservation in building sectors as well as for reduction of CO_2 gas emission coupling with the current global warming issues. It is reported, however, that the energy conservation is not achieved in the real field due to lack of proper operation of the system. In this study, presupposing cooling load prediction technology, optimal operation schemes are developed and verified in simulation bases.

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We are researching and developing the in-plant technology for LiBr concentration measurement in an absorption refrigerator with the absorbent of LiBr aqueous solution and the coolant of water. In this paper, the application of a capacitance sensor composed of a cylinder electrode with two different diameters to the LiBr concentration measurement was experimentally studied using 3 kinds of non-hygroscopic strong electrolyte i.e. NaCl, KCl and K_2SO_4 aqueous solutions, before using LiBr aqueous solution with strong hygroscopicity. As a result, it was clarified that capacitance and pH could be respectively expressed as a approximate function of non-dimentional solubility of solute without regard to kinds of electrolyte, and that the solute concentration could be measured in the high precision and wide range by using the above two functions. Also, it was clarified that the specific dielectric constant of the above salt aqueous solutions in saturated concentration range could be estimated by introducing an electric equivalent diameter method instead of the geometrical diameter for the upper vessel part of the cylinder electrode with two different diameters.

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This study presented a simulation method of thermal environment and heating and cooling load in spaces conditioned by air-handling units together with hydronic floor panels. The presented method enables the detailed simulation of the dynamic response of floor for thermal injection by hot or chilled water and thermal environment in spaces where operative temperature is controlled by air-handling units and floor surface temperature is controlled by floor panels. The fundamental characteristics of several types of heating operation and the effects of factors such as set point floor temperature and warming-up hours were clarified through simulations.

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An algorism to generate myriad schedule data of each inhabitants' behavior that is provided by a fine time resolution was shown. This procedure seems to be useful to estimate energy and utility requirements such as electricity, gas and water demand in a residential building, a certain district and an urban area, especially for a prediction of maximum loads of those. The method is evolved from the previous one authors' proposed, and is based on several public statistical data. The proposed method can deal with a simultaneous behavior (watching TV with another behavior), adding at-home-flag and family formation, which are necessary for practical calculations.

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Proper maintenance and energy saving must be considered to environment-consciously run building services during their lifecycles. Proper maintenance leads to the effective use of natural resources, in particular. Maintenability relates to reliability very much. Reliability has been originally highlighted in the high-speed transportation system like airplane and bullet train from the safety point of view. Now that many complex and high-performance buildings requiring security like internet data center and biomedical facility increase, reliability of building services should be paid much attention. Proper maintenance has been seldom employed due to the lack of necessary reliability data and reliability knowledge. There are several maintenance guidelines showing how frequently the maintenance should be done for building services or its components. But the guidelines are seldom based on both enough reliability data and acceptable explanations. This paper tries to correct the ambiguous guidelines and illustrates a reliability study for fire tube boiler by mainly applying Cumulative Hazard Analysis with actual operational data in about ten years. The analysis was carried out on the boiler's 19 components by taking into account of the manufacturers' maintenance guidelines. As a result their MTBFs (Mean Time Between Failures) were estimated spanning from 1.0 to 5.0 years. The Weibull distribution shape parameters with Cumulative Hazard Analysis were from 0.61 to 2.68. The blow-through fan for burner was a sole component being planned time-based maintenance. Since the shape parameters of air volume control damper, water supply pump, water supply pipe and water level detector showed they had initial failures, it is of necessity to think about their design and construction methods.

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Recently, multi-package air-conditioners (unitary air-conditioners composed of one outdoor-unit and plural indoor-units) are used widely in many commercial buildings of not only small scale but also middle scale buildings. Therefore, improvement of their energy consumption efficiency is becoming more and more important problem. Result of investigation on the manufacture's catalogues, especially focused on energy consumption efficiency, is reported in this paper. Much practical information is obtained. For instance, although many manufactures apply same housings and same size fans in close but different capacity machines of the outdoor-units to reduce production costs, it is found that energy consumption efficiency is often sacrificed in such cases.

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