This paper describes a performance analysis of a ground source heat pump (GSHP) with plate-type heat exchangers using ammonia as working fluid. To improve thermal and economical efficiency of GSHP, it is essential to enhance the efficiency of GSHP components (ground heat exchanger pipes, evaporator, condenser, compressor etc.) and to optimize total systems of GSHP. Since the ground heat exchanger pipes occupies high ratio of total initial capital cost, we proposed the optimization method of the length and the number of pipes. The performance analysis presented in this paper make possible optimal design of the length and the number of ground heat exchanger pipes in various conditions.

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It has been well-known that photocopy machine generates ozone, when it is operated. Ozone is so harmful that the exact prediction method of the indoor ozone concentration has been needed for evaluations of health effects or buildings design. If we wish to predict the indoor ozone concentration correctly, we should determine the emission rates or the emission characteristics of the sources as well as the ventilation rate of buildings. In this study, we established the exact prediction method on the indoor ozone concentration when office equipments were operated. We also achieved the chamber-test method to determine the ozone emission rates on each office equipment.

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This paper determines the priority of waste management and two important and quantitative indices, landfill amount and CO_2 emission, were settled as protection targets at first. According to the previous study, kitchen refuse and a part of plastic packaging materials can be separately collected. Separate collection of these fractions and construction material production from incineration ash are main controllable diverging points of waste flow. There are various ways of waste treatment corresponding to the diverging points, whose specific landfill amount [m^3/t waste] and specific CO_2 emission [kg-CO_2/t-waste] were deducted through investigations. At last through the case study was carried out to evaluate the effect of waste flow control on the landfill amount and CO_2 emission within the system boudary of waste and waste water treatment. As a result construction material production from incineration ash can lead to decreaese the landfill amount without increasing CO_2 emission.

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Indoor relative humidity is stipulated for an important point in indoor environment regulations such as Building Control Code and Industrial Safety and Health Code in Japan. Based on the findings of indoor environment studies carried out during the winter, however, relative humidity is below standards in many buildings. Aiming to clarify the actual state of indoor relative humidity and improve it during the winter, we have selected sixty-nine office buildings located in Central Japan and carried out a study. We have also investigated actual performance of popular humidifiers that are frequently used in air-conditioning systems. Throughout this study, we classified the factors that degrade indoor relative humidity into two categories. One consists of factors caused by building side such as infiltration and decreased winter loads. The other consists of factors caused by humidifier such as low performance at low indoor temperatures. Given that the winter load in office buildings has tended to decrease because of improvements of building insulation and increasing number of office equipment used in office buildings, almost all the popular humidifier except the steam type failed to maintain performance due to low indoor temperatures. For the reasons mentioned above, we developed a high-efficiency humidifier system that uses a two -phase flow nozzle is a spray humidifier for industrial use. Because its spray particles are smaller than those of popular spray types, its performance is not affected by indoor air temperature. This report presents results of the investigation and methods of improvement including development of a high-efficiency humidifier system. Results indicated that about 80% of office buildings studied could not maintain relative humidity to standard during the winter. Relative humidity remarkably improved in office buildings which had a high-efficiency humidifier system with two-phase flow nozzle was installed. If steps are also taken for the building then relative humidify in office buildings will further improve. Improving humidifier performance and buildings systems improved the indoor relative humidity as well as the effective temperature.

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