As a very aged society, present-day Japan has an increasing demand for numerous elderly facilities with good environment in terms of both thermal aspects and odor. This study examines the characteristic thermal and odor environment, as both elements are related, of such facilities through practical observation during summer.
Two facilities, A, built in 2009, and B, built in 1997, were the survey targets. In each facility, the parameters of thermal environment, i.e., temperature and humidity, were continuously measured at a representative point for 24 h. Four activity-meter-equipped care givers attending the elderly were asked to participate during this period. They were given a questionnaire to answer approximately every hour, and their behavior during the measurement was visually observed and then recorded.
Similarly, continuous measurement for odor environment was performed every 30 min using a hot-wire-type semiconductor gas sensor, smell evaluation by the researchers, and measurement by an ammonia detection pipe. Moreover, a 250‐L odor sample was placed into a collection tube. Evaluation procedures for the odor included a “6‐stage odor intensity evaluation,” a “9‐step free discomfort evaluation,” and a “smell quality evaluation” based on the semantic differential (SD) rating scale.
Measurement results for the thermal environment indicated that facility A had higher temperature than facility B. Additionally, even when the same PMV values were assessed for the elderly and the caregivers, the latter deemed facility A as “hot” and “uncomfortable” owing to high temperature, which exceeded the recommended comfortable range.
In contrast, odor concentration in facility A was 63, whereas it was ≤10 for facility B. Smell evaluation and odor component analysis both detected odors of sweat and building materials, particularly in facility A, which were thus presumed as sources of odor generation and emission. Based on the amount of generated odor, facility A requires a ventilation rate of 6.3 times/h rather than the current 2.6 times/h, whereas facility B, operating at 1.9 times/h, met the threshold requirement.
Thus, facility A exhibits an excessive thermal environment that potentially leads to odor generation. An in‐depth study of the relationship between thermal and odor environment, with sufficient accumulation of data, will be explored in future work. Nevertheless, given a comfortable thermal environment, we believe that a ventilation rate of 2 times/h is suitable in this case.
