著者

姜 允敬 加藤 信介 成 旻起 金 鐘訓 柳 宇 阿部 恵子 原田 光朗 柳原 隆司

出版者

日本建築学会

雑誌

日本建築学会環境系論文集 (ISSN:13480685)

巻号頁・発行日

vol.76, no.667, pp.793-798, 2011-09-30 (Released:2012-01-13)

参考文献数

17

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For possible applications in the humidifier-elements of air-conditioning systems, we investigated the germicidal effect of microwave irradiation on fungal spores, e.g. Cladosporium herbarum and Fusarium solani as well as bacteria, e.g. Bacillus subtilis. For the irradiation of our samples we used a general-purpose microwave oven as well as a specially assembled microwave source that could emit microwave radiation at a frequency of 2.45 GHz. In our first experiment, we determined the optimum condition of the two parameters of radiation output power and exposure time to achieve the desired germicidal effects. Microbes on both dry and wet filters were used as samples. The second part of the study was aimed to determine whether the germicidal effect originates directly from microwave irradiation or rather from the radiation-induced heat. Our results indicate that the degradation of microbes is affected by the type of strain, microwave output power, exposure time and sample moisture (and thus induced temperature increase). And it was identified that germicidal effect by microwave is mainly due to the thermal effect.

著者

成 旻起 加藤 信介 田中 堤子

出版者

日本建築学会

雑誌

日本建築学会環境系論文集 (ISSN:13480685)

巻号頁・発行日

vol.74, no.639, pp.621-627, 2009-05-30 (Released:2009-11-30)

参考文献数

12

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UVGI (Ultraviolet Germicidal Irradiation) system is recently considered for the sterilization of indoor air and practically applied to the buildings where need hygienic control mainly in America and Europe. In this study, the factors influencing the germicidal effect such as UV intensity and exposure time were reviewed and the several methods to evaluate the germicidal efficacy of UR (Upper Room)-UVGI system were introduced. The methods mainly use CFD simulation to calculate UV dose, considering the distribution of UV intensity of UR-UVGI system and the air flow induced by air handling system in a room. The methods were applied to a typical 4-patient ward model. Results showed that the positions of UR-UVGI system and supply or exhaust openings are important for UV dose. For example, spatial average UV dose decrease when UR-UVGI system is installed near the exhaust openings. Similar results were shown in the cases that the contaminants assumed to be exhausted from the mouth of patient. In the cases assuming infectious microbe flow in through supply openings or breathing of occupant, the germicidal efficacy of UR-UVGI could be evaluated with the methods.