To achieve cascade energy use, chilled water is used for air-conditioning more than once and multiple heat loads are processed by connecting air conditioners in series. This method is expected to reduce the energy required for air-conditioning energy. Before this study, cascade energy use between two air conditioners was examined in a building. Experimental results showed that heat load cannot be processed properly at the second air conditioner because water flow rates are reduced at the first air conditioner. In this paper, we consider a system to process heat load properly and introduce the effect of cascade energy use. Through some simulations, we propose two systems in which the number of coil rows is selected and chilled water is distributed to the first and second coils, respectively. It is shown that room temperature is properly maintained with both systems, but the room temperature occasionally rises and falls in the former system. It is also shown that the latter system can conserve pump energy, while the former system increases pump energy, compared to a discrete heat source system.

The use of natural ventilation to improve the comfort of a room is considered difficult because the indoor ventilation performance will decrease on increasing the floor space. In this study, we evaluated the performance of a natural ventilation system in a large-floor-space office by calculating the inflow and outflow of air through a ventilation window based on differential pressure measurement. To evaluate performance, we analyzed the relation between outside wind at the time of natural ventilation and air inflow and outflow through a ventilation window. The results show that the eastern and northern faces have greater inflows, and an outside wind direction that is more toward the windward side with respect to each surface tended to yield a greater air inflow. In addition, we calculated the air change per hour in a residential area by the carbon-dioxide method. It was clarified from the CO₂ concentration that the ventilation performance is different for each measurement point. As natural ventilation resulted in a warm indoor temperature environment, we analyzed the relation among the temperature different between the inside and outside, air inflow and outflow, and the indoor temperature environment. The results show that the temperature difference between the inside and outside became small with natural ventilation, and the difference tended to fluctuate with a change of air inflow and outflow. In addition, the indoor temperature was within ± 2 degrees Celsius from the air-conditioning temperature setting of 26 degrees Celsius. We evaluated the thermal sensation of people in the office at the time of operation of the natural ventilation system by a questionnaire survey.

This study investigated the effect of a peppermint fragrance on the performance of a memory task as well as on the physiological and subjective sensation during the task. Ten healthy male participants were exposed to indoor conditions with or without the peppermint fragrance. They performed memory task for 7-to-9-digit numbers in a climatic chamber controlled at 28°C and 50% relative humidity. During the experiment, the cerebral oxygenation level was evaluated using the near-infrared spectroscopy on the forehead. The heart rate, inner ear temperature, skin temperature, forehead skin blood flow, and forearm local sweat rate were continuously measured. Thermal sensation and comfort, subjective sweat sensation, and perceived temperature were assessed eight times. The results showed that there was no significant difference in the task performance between fragrance conditions. In the peppermint condition, the cerebral oxygenated hemoglobin level and heat rate were slightly decreased during the task. This result suggests that the peppermint fragrance might decrease the physiological strain during the cognitive task, even with a similar performance level in the memory task. Thermoregulatory response and subjective sensations showed small changes during the experiment, but no significant difference was observed between the two conditions.

In recent years, the green movement has been sweeping across our society. Some studies provide evidence for the economic value of certifying “green buildings”. It is difficult to evaluate the economic value of energy-savings investments without risk quantification. An effective method for risk quantification is the Monte Carlo method, which yields the distribution of an unknown probabilistic entity with repeated random sampling. In this study, a stochastic model of tenant characteristics was developed to apply the Monte Carlo method. Based on the past survey results, the ratio of occupancy was estimated by industry and employment type. The ratio of occupancy by age was also estimated. In addition, based on the results of the questionnaire in the author's previous study, the frequency of the starting time, lunch-break starting time, and lunch-break time was sorted. This statistical information was integrated to stochastic models developed in previous study. The tenant entry and exit model in the past study and the above tenant attribute model were integrated. The occupancy rate for each time was calculated for the entire building and one tenant, respectively, and the uncertainty of the occupancy rate was evaluated according to the scale of the calculation target.

Firstly, public information on the current housing status and residential energy consumption in Lao People's Democratic Republic are reviewed. The statistical data show that consumer durables such as cars and TVs have spread rapidly and the residential electricity consumption has increased sharply in Lao PDR over the past dozen years or so. Secondly, the results of a questionnaire survey of high-income households conducted by the author between 2014 and 2017 are presented. The results of the 2017 survey show that the average highest-income household in Vientiane Capital has 3.2 TVs and 4.8 air-conditioners and consumes 1 160 kWh per month.

This paper presents a flexible and expandable database of the equipment characteristics of air conditioning in which interactions among building equipments are well considered. These characteristic databases are always maintained in a neutral and fair manner by the five subcommittees, which are not influenced by any specific manufacturer. In this paper, the importance of modifiability of equipment databases, the expandability of equipment databases, and the details of developing equipment characteristic databases are discussed. This database has three data sets (nominal performance characteristics, part load performance characteristics, and dynamic performance characteristics) which are solved by applying two modeling methods (empirical model and/or physics-based model) to represent equipment characteristics to provide shorter calculation cycles in the coupled calculation within the entire building calculation. Energy consumption by this database is validated via sensitivity analysis. The central heat source that performs unit number division is significantly influenced by dynamic performance characteristics, while the decentralized cooling and heating equipment is significantly influenced by methods for representing equipment characteristics under the minimum part load ratio.

LED lighting with easily controlled brightness and color temperature might be useful for improving indoor comfort by changing its color temperature setting. The hue-heat effect is the impact that warm and cool colors have on thermal sensation, such as feeling warm in red surroundings, or cool in blue surroundings. This effect is not well understood, so in this study we investigated the influence of color temperature with different air temperatures on indoor comfort by conducting subject experiments every season from three points of view: “indoor atmosphere evaluation,” “thermal environment evaluation,” and “workability evaluation.” As part of the study, we clarified the thermal step-change condition that occurred when subjects moved between chambers. The result showed that only if subjects received a large thermal stress in the ante-room, then the color temperature influenced the evaluation of thermal environment corresponding to the hue-heat hypothesis immediately after entering the chamber.

Tokyo Bunka Kaikan was opened in 1961 as a memorial on the 500th anniversary of the establishment of the capital. It is famous as Music Hall of Fame, where international performances are conducted. In renovation work we succeeded the goodness hall acoustics and aimed at improving the indoor environment and energy use. To ensure the comfort of the viewer and performer as well as the ideal temperature and humidity conditions for the instruments, the temperature and humidity were improved in the large hall, orchestra pit and small hall, and the distribution of airflow was made uniform. In addition, an air conditioning noise of NC - 19 or less was achieved. In this report (Part 1), we will describe the design and improvement of the indoor environment based on actual measurements with CFD analysis.

Most design data used for water-supply calculation are data of past statistics. The water consumption of hospitals has been drastically decreasing because of activities such as the outsourcing of linen work. It is necessary to calculate the water consumption as accurately as possible at the design stage because hospitals are used 24 hours a day throughout the year, water is necessary for many activities, and a large number of people use water. We analyzed the water consumption per bed using the actual water consumption data of a hospital, developed a calculation model based on the analysis result, and performed calculations using the water load calculation method.