The purpose of this study was to determine the conditions necessary for the total eradication of mite pests in indoor environments. The study involved the construction of a sterilization experimental setup. For this setup, various sterilization techniques, such as UV-C, ozone, ultrasound, and heat were applied, based on previous research. The experimental procedure consisted of placing mite pests in a chamber and subjecting them to different sterilization techniques. Observations were conducted immediately after the experiment and repeated five days later to assess the extent of eradication. The results showed that UVC, ozone, and ultrasound methods were not successful in completely eradicating the mite pests. In contrast, heat sterilization demonstrated effectiveness depending on the specific temperature and exposure time. To achieve the eradication of mite pests in indoor environments, it is necessary to maintain conditions of short-term high-temperature sterilization above 65°C or sustain temperatures above 50°C for a minimum duration of 90 minutes.
Recently a high-rise building is built in many places. However some problems are occurred in the high-rise buildings. Especially, at the case of the kitchen exhaust using vertical shaft, the kitchen exhaust fan sometimes can not work normally because of unbalance of pressure inside the shaft. In this study, under the assumption that the kitchen exhaust system applied uniformly can not cope with the various changes of the outside environment, the vertical sectional characteristics of a kitchen exhaust using vertial shaft is analyzed. Outside temperature, number of the floors and operating ratio of the vertically connected fan are selected as major parameter. And it is analyzed by a network simulation method. In case of 60 stories building, the standard deviations are 115.6 at the second floor, 74.9 at the 30th floor and 20.7 at the 60th floor. The standard deviation at the lower part is about 5.5 times than the upper part. So the results of the simulation show that the kitchen exhaust system should be installed considering the vertical sectional exhaust characteristics.
This paper describes to evaluate the performance of ventilation as a change of CO2 concentration with ventilation rate under 35 occupants in a school classroom. Variations of the CO2 concentration as a function of time are measured at center point of classroom with air ventilation rates by the CO2 gas monitor. For 800 m3/h of ventilation rate in the classroom, the average CO2 concentration is 913 ppm. The ventilation rate is sufficient to meet acceptable indoor air quality (≤ 1,000 ppm of CO2, KS school standard) in the classroom of 35 students.
In this study, the odor of the parts and the odor of the surrounding environment were classified and verified. In order to increase the reliability of odor quantitative/qualitative analysis, the selection criteria for 5 sensory evaluators were established, and the n-Butanol control solution for each odor intensity was periodically trained to recognize the odor intensity before sensory evaluation. In addition, although various odor thresholds have been used through several studies, verification of whether the odor intensity value obtained through GC/MSD analysis is similar to the degree to which a person directly smells and feels it. It is important to select the odor threshold that has the best correlation with the odor intensity calculated by the person smelling the odor. Finally, sampling and measuring flowing airflow and temporary odors such as odor component analysis was experimentally difficult due to limited collection space and differences in concentration of generated components. In this study, a quantitative analysis was made possible by using the low temperature concentration (cooling) trap method. Through this, it was confirmed that the correlation with the actual odor intensity was not caused by the product itself, but by the environmental factor discharged from the product after creating the odor environment.