We proposed a multisource and multi-use heat pump (MMHP) system that attains a higher coefficient of performance (COP) than conventional heat pumps. The MMHP system extracts thermal energy from multiple heat sources/sinks such as solar heat, ground, and air and provides it to multiple heat uses such as cooling, heating, and hot-water supply with a water loop. Each use side can be expected to achieve high efficiency. Although there are many water-source heat pumps for air conditioning, these existing heat pumps are not suitable for the water-source temperature range of this system. Therefore, we developed a water-source heat pump that is suitable for this system for air conditioning. The development of the water-source heat pump combined with air conditioners is presented in this paper. A prototype of the water-source heat pump is developed, and good performance is achieved by adjusting the control of the expansion valve. The COPs of the cooling and heating modes were 10.1-14.2 and 4.8-5.1, respectively. On the basis of the experimental results, a performance curve of the prototype was created, which can be used for simulations.

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Central-exhaust ventilation systems operate 24 h a day and exhaust formaldehyde gas or volatile organic compounds. For such systems in newly constructed houses, door undercuts are often applied as the exhaust openings of bedrooms. However, in order to exhaust CO_2 and the humidity generated by the occupants in the bedrooms efficiently, installing an opening in the vicinity of the top of the door might be more effective than that in the door undercut. In this paper, an appropriate exhaust route in a bedroom is examined on the basis of experiments and a CFD simulation. The results show that installing the opening in the vicinity of the top of the door is more effective than the door undercut to exhaust contaminants generated by occupants, and a remarkable difference in their temperature distributions is not observed.

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In Japan, the rate of the 65 and over years-old (rate of aging) population occupied to the present overall population has reached to 25.1% in 2013, and this is expected to progress to becoming an aged society hereafter. In general, as the immunity of aged people is quite low, they tend to suffer from so-called opportunistic infections. Therefore, it is important to examine indoor air environments of welfare facilities for the aged. If there are problems in particular on the actual status of microbial contamination, it is necessary to examine the countermeasures. In this study, the environments of eight rooms of 5 facilities were examined. The sites of investigation include the day room where inhabitants gather, the room where the facility residents stayed for a long time, and the outdoor. Measurements were carried out twice at each site from August to October 2011 (summer), and January to February 2012 (winter). Furthermore, to clarify the time-dependent-change-changes in the characteristics with regard to both the indoor airborne microbial concentration and the type of species, the environments of the day rooms were continually evaluated during summer, in terms of airborne bacteria and airborne fungi. The detailed analysis of microbial contamination using the DNA analysis technique revealed, the following findings: (1) The range of fluctuation of concentration the airborne bacteria and fungi in the day room has increased 100 to 1000 fold, and it is difficult to grasp the actual condition of contamination of indoor bacteria and fungi by a momentary measurement. (2) Except at one facility, 75 percentile of the airborne microbial concentration (including bacteria and fungus) in 4 facilities of the Architectural Institute of Japan satisfied the standard value of 500 cfu/m^3, but various bacilli causing opportunistic infections, such as Staphylococcus hominis, S. epidermidis, Serratia marcescens, Corynebacterium xerosis, C. freneyi, Acinetobacter baumannii, A. calcoaceticus, Stenotrophomonas maltophilia, are detected. (3) Since many opportunistic infection-causing bacteria exist in these welfare facilities, preventive measures are required to ensure safety of the aged people who have special care requirements.

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This research aims to propose an effective means for achieving the appropriate operation of a heating and cooling plant by initial commissioning using simulation. In this study, we considered the criterion that verifies the performance of the designed heating and cooling plant system in the design step by simulation. First, case studies of design verification by simulation are performed. Then, the simple energy calculation carried out with typical design parameters is compared with the detailed system simulation performed during the design phase with regard to the methodology and results. As a result, the importance of the simulation during initial commissioning is confirmed. Further, the required calculation for initial commissioning is described.

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