Various indoor air pollution caused by reduced air change rate in recent Japanese houses, which comes from highly insulated building envelops as an energy conservation measure, is getting very serious social problems in this country. Some of them is called “sick house syndrome”, which is an indoor air quality (IAQ) problems caused by chemicals emitted from building materials, and is drawing an enthusiastic public attentions. However so far as a lung cancer, indoor radon is much higher risk than those chemicals. Literature review was made in order to clarify present status of the pollution and to overlook the indoor radon pollution research in this country. The results show that the most important point of understanding the radon progeny behaviors and of developing the mitigation measure is air exchange including ventilation. It is strongly expected that consensus on the radon risk and lung dose should be reached among the researchers of health physics and environmental standards should be set based on the consensus. It is also expected the instruments which can exactly measure by the inexperienced persons in order to establish the radon inspection systems.

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A large number of deaths while bathing at home are reported in Japan, most of them among the elderly during winter. Since cold exposure and large temperature variations cause serious diseases, the reason for these accidental deaths might be cold exposures before, during and after bathing, and bathing in very hot water. We have reported that, in cold environments, the blood pressure of the elderly increase more rapidly than that of young people and that, in addition, there is a delayed sensitivity to cold in the elderly. These physiological and psychological responses during winter bathing put the elderly at high risk of serious diseases such as a cerebral apoplexy and ischemic heart disease. The installation of heating equipment in winter in Japanese houses is recommended. In this paper, the characteristics of bathing in Japan were reviewed on the basis of our several field and experimental studies.

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The acoustic environment was examined in an office building with a high prevalence of symptoms typical of the sick building syndrome (SBS). Levels of ventilation noise exceeded 70 dB in many rooms. The peak was often found in the region below 20 Hz, which is the infrasound region and generally regarded as inaudible at these levels. Symptoms attributed to exposure to low frequencies include nausea, headache, choking, coughing, visual blurring and fatigue, which appear to overlap with some of the symptoms of SBS. Reducing fan speeds provided reductions in noise levels mainly in the audible region. Closing windows and doors to the rooms gave more effective reductions, but interfered with working routines.

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In this paper, a zonal model used to predict the air movement, temperature distribution and air quality in a room is presented. It is based on a rough partitioning of the room: It is an intermediatc approach between one-node models (that consider an homogeneous temperature in each room, and, for that reason, do not permit to predict the thermal comfort in a room) and CFD models (that require great amount of simulation time). Where plumes, jets or thermal layers occur, air flow is described by empirical laws. In low velocity domains, flow rate are calculated in respect to the pressure distribution. This air flow model is coupled with a building envelope model including the calculation of radiant and conductive exchanges. The complete model is implemented in an object oriented enviroment, SPARK, in which modelling a room consists in connecting the different pre-design elementary models. Hence, the way of modelling is very modular, so that the zonal model can now be applied to a very large field of configurations. The strict syntax of SPARK permit having the simulation automatically generated. Now, imagining the creation of a very flexible tool that allows to represent a whole building is realistic.Results of simulations in a 3D-room will be given and it will be shown that this model yields rather accurate results even with a rough partitioning.

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Human vision is often incapable of detecting the impact of environmental conditions or perceiving the different environmental factors in the three-dimensional geometry of the work place. Augmented Reality (AR) is an emerging new human-computer interface paradigm that has the potential to solve such problems. AR augments a user's view of the real world with virtual objects superimposed upon or composite with the real object. Over the past two years, a computational model has been developed to help implement an augmented reality system for building thermal design. The model allows users to manipulate building envelope parameters and materials, invoke a simulation model and display the heat transfer information and comfort conditions in a virtual environment. The model contains a Java module and an interface module. The Java module contains the simulation engine and functions that manipulate the interface and has been implemented as an object oriented module. The goal is to test the applicability of the representation of the thermal simulation and the visualization techniques before fully integrating them with the augmented reality system. The system will allow users to remedy problems on site by enabling them to try various combinations of building components and to test their impact within an interior space.

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Although there are many factors contributing to the quality of luminous environment, lighting design standards are almost entirely based on one predominant parameter, namely illuminance level for task performance. In this paper we will discuss the limitations of such a practice based on the findings made in terms of visual comfort and users preferences in lighting.

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This study examined the effects of change in environmental temperature on the autonomic nervous system. Ten female subjects were exposed to two levels of temperature in different rooms. The temperature in Room 1 was set at 21 or 28°C while that in Room 2 was set at 35°C. Subjects were exposed to four different combinations of temperatures and periods: movement between Room 1 and Room 2 every 10 min (condition A) or 40 min (condition B) and between Room 1 and Room 2 every 10 min (condition C) or 40 min (condition D). At the condition A and B, Room 1 was set at 21°C , and it was set at 28°C at the condition C and D. The control group was kept in Room 1 maintained at a constant temperature of 26.5°C for 165 min (condition E). The experimental time totaled 165 min including the 5-min period immediately after the start of experiment. It was clarified that the invasion to the autonomic nervous system tended to be largest under condition B (moved every 40 minutes maintained at 21 and 35°C) by the results of Coefficient of Variation of R-R interval (CVR-R) and low-frequency (LF) and high-frequency (HF) components of ECG. Briefly, it was suggested that autonomic imbalance tends to occur when temperature difference is great or exposure to low temperature lasts long.

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With a purpose to investigate the relationship between average skin temperature and wettedness of man that feels an equal thermal sensation, the experiments were conducted on sitting-resting subjects in a test chamber. The subjects were dressed in athletic short and were exposed to warm conditions for one hour.From the analysis of the present experimental data, the following conclusions were drawn regarding an equal thermal sensation. When subjects voted the thermal sensation “warm”, the average skin temperature and the skin wettedness hold different values depending upon the different combinations of ambient air temperature and environmental humidity. In other words, as the humidity gets higher, the average skin temperature goes down and the skin wettedness becomes larger. Further the data suggest that both experimentally and theoretically the locus of equal thermal sensation may not be a straight line, but rather a curved line plotted on a psychrometric chart.

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