Motoya Hayashi

MANAGEMENT SITUATION OF INDOOR ENVIRONMENT AND HVAC SYSTEM IN FACILITIES FOR THE ELDERLY

Japan has been well on the way to an aging society and entered a super-aged society at 21.5 percent aging rate in 2007, and the facility demand for the elderly is increasing rapidly. However, the actual situation of indoor environment had not been clear because there is not a regulation and control law at all. It is critical to understand the facility managing system and the actual condition of indoor environment in order to improve quality of life such as health and comfort and to prevent infectious diseases in care welfare facilities for the elderly. Cross-sectional study utilizing the questionnaire survey on special nursing homes all over the country was conducted to clarify the management, maintenance and actual condition of indoor environment and building equipment in 2013. As a result, the installation of individual air conditioning equipment expanded countrywide due to benefits such as initial / operating costs and high energy performance. the control criteria of air temperature were set in about 60 percent of the facilities, while those for relative humidity and ventilation were less. Most of the facilities set control criteria for indoor environment factors within commonly-accepted levels, but a problem also was seen in knowledge and recognition of facility managers for HVAC and ventilation system. In order to secure and maintain the favorable indoor environment and hygiene in the elderly facilities, it seems appropriate to remark that a professional administrator should be employed as a facility manager, and they should be educated and provided with the related knowledge and techniques.

Estimation on humidification and ventilation for infection control in residence for the elderly

Purpose / Context - The aim of this study is to clarify an estimation method of humidification for infection control in residences. In Japan indoor humidity is very low in winter especially in recent insulated houses without unvented stoves. Dwellers know that it is necessary to keep humidity ade-quate for infection control, but most of them don’t know the moderate humidity or the effect of venti-lation for infection control. In this study, the state of influenza infection control was evaluated using the measurement results on indoor air in the rooms of six Japanese facilities for the elderly. The temperature is kept better in these residences than that in common Japanese houses. But the humid-ity is quite very low in winter. The energy saving is thought to be one of the causes of this state. Methodology / Approach - Under the assumption that influenza virus generate at a constant rate, the concentrations of survived influenza viruses in indoor air were calculated using an equation, which is given on the basis of the survival tests on influenza virus by G.J.Harper. The equation gives the concentration of influenza viruses using the ventilation rates and absolute humidity. Then an index on virus reduction which integrates ventilation effect and humidity effect was proposed. Results - The energy consumption of ventilation and humidification for infection control is calculated using this index. The results show that it is effective to control ventilation rate for both of infection control and saving energy in many rooms in these facilities. Key Findings / Implications - Effective strategies for infection control in residences are discussed using the index of influenza infection control. Originality - The index of influenza infection control is proposed in this study. This index is useful to estimate indoor air quality. The index is expected to be used for the design of building performances and air conditioning systems.