Study on the Ventilation Rate based on Perceived Air Quality of Tobacco Smoke and Bioeffluents

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In conformity with the purpose of research various methods for assessing the indoor air quality using human olfactory sensation have been proposed and the results of experiments presented as summarized as follows:In chapter 1, "Sick Building Syndrome", which presented the complaints about the indoor air quality in non-industrial buildings, was reviewed.In chapter 2, the relationship between the ventilation rate per occupant and the percentage of dissatisfied judges for Japanese was described through the subjective experiments. The purpose of this study was to investigate the indoor air quality by making subjective assessment of perceived air pollution caused by human bioeffluents. Fifty-four subjects ( 27 females and 27 males ) were hired as occupants, who emitted human bioeffluents during occupancy in the test chamber. One hundred and seven subjects ( 52 females and 55 males ) were hired as judges. Immediately after sniffing the air, the judge rated odor intensity on Yaglou's scale, a … More nd assessed acceptability.The relationship between the mean odor intensity and the percentage of dissatisfied judges, i.e., those judges who judged the odor to be unacceptable, was found to be a close one. It appeared that 20 % dissatisfied, which is acceptable air quality defined by ASHRAE standard 62-89, corresponded to a CO_2 concentration of 995 ppm when an outdoor CO_2 concentration was 370 ppm. It was clarified that CO_2 concentration could be a reasonable predictor for perceived air quality in non-smoking spaces. The relationship between the percentage of dissatisfied judges and the steady-state ventilation rate per person was determined. Then it was found that 20 % of dissatisfied would correspond to a steady-state ventilation rate of 7.1 1/s・person ( 25.6 m^3/h・person ). The relationship between the ventilation rate per olf, which is an unit describing the perceived air pollution source strength proposed by Fanger, and the percentage of dissatisfied judges for Japanese subjects agreed well with that for Danish subjects. It might be possible, therefore, to determine the appropriate ventilation rate for acceptable air quality using the olf and decipol units.In chapter 3, tobacco smoke was used as perceived air pollution source in the test chamber where three measuring point were prepared. The trained panel judged the air quality of each measuring point, and "age-of-air" was calculated from a decay of tracer gas (SF_6) concentration. Distribution of perceived air pollution was assessed with half-life-time of perceived air pollution at three measuring points in the chamber, which was calculated from a decay of decipol values voted by the trained panel. Then the ventilation effect in the chamber was assessed with "Air Diffusion Efficiency" calculated from age-of-air. The half-life-time of perceived air pollution had strong correlation with the age-of-air except for the case of low air change rate, and it could be possible to assess the ventilation effect based on the distribution of perceived air pollution using trained panel.Human bioeffluents and tobacco smoke were used as pollution sources with 3 different cooling-ventilation systems in Chapter 4. The relationship between the Air Diffusion Efficiency and the removal efficiency of perceived air pollutants was investigated. Perceived Air Quality Index was proposed for evaluating the local air quality in a space based on human olfactory sensation. The removal efficiency of perceived air pollutants was calculated from the Perceived Air Quality Index. Then it was found that distribution of perceived air pollutants did not always correspond with that of supplied air. It is considered important, therefore, to identify not only the local age-of-air,but also the local perceived air quality.In chapter 5, removal efficiency of perceived air pollutants caused by tobacco smoke was measured under the three different heating-ventilation systems. Perceived Air Quality Index (PAQI) at each measuring point was investigated with trained panel and local age-of-air was determined with tracer gas. For the system, which had an inlet on the lower part of the side wall and an outlet on the upper part of the side wall, the highest ventilation effect was obtained. Less