• Journal of Korean Society of Environmental Engineers
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• v.39 no.1
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• pp.19-25
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• 2017

In this study, a electrostatic filter which could be applicable to road environment was developed and evaluated in adsorption capacity. The evaluation were performance for removal by particle size and adsorption amount by pressure using ASERAE 52.1 and 52.2. The range of size for removal test was $0.3{\mu}m{\sim}10.0{\mu}m$ which had 12 steps. The filter showed 91.3% removal efficiency from $2.5{\mu}m$ and under the size, average 53.5% proportional to decreasing size value. The weight removal was 96.7% from 22.6 mmaq, initial pressure to 35 mmaq, end pressure with $715.9g/m^2$, the adsorption amount. The shape of isotherm was expressed as Langmuir's one. After washing saturated filter with dust to end pressure, the initial pressure and adsorption amount of the filter showed a light drop with no removal efficiency decline.

• Journal of Bio-Environment Control
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• v.28 no.3
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• pp.204-211
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• 2019

The purpose of this study is to provide basic data for setting environmental design standards for domestic greenhouses. We conducted experiments on thermal environment measurement at two commercial greenhouses where hot water heating system is adopted. We analyzed heat transfer characteristics of hot water heating pipes and heat emission per unit length of heating pipes was presented. The average air temperature in two greenhouses was controlled to $16.3^{\circ}C$ and $14.6^{\circ}C$ during the experiment, respectively. The average water temperature in heating pipes was $52.3^{\circ}C$ and $45.0^{\circ}C$, respectively. Experimental results showed that natural convection heat transfer coefficient of heating pipe surface was in the range of $5.71{\sim}7.49W/m^2^{\circ}C$. When the flow rate in heating pipe was 0.5m/s or more, temperature difference between hot water and pipe surface was not large. Based on this, overall heat transfer coefficient of heating pipe was derived as form of laminar natural convection heat transfer coefficient in the horizontal cylinder. By modifying the equation of overall heat transfer coefficient, a formula for calculating the heat emission per unit length of hot water heating pipe was developed, which uses pipe size and temperature difference between hot water and indoor air as input variables. The results of this study were compared with domestic and foreign data, and it was found to be closest to JGHA data. The data of NAAS, BALLS and ASHRAE were judged to be too large. Therefore, in order to set up environmental design standards for domestic greenhouses, it is necessary to fully examine those data through further experiments.

• Proceedings of the SAREK Conference
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• 2008.06a
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• pp.1392-1397
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• 2008

This study is to measure the change of the $CO_2$ and floating dust concentration depending on the volume of the ventilation and the state of on/off the ventilation for the estimation of the air pollution in classroom. The results could be summarized as follows: the test cell was the two full scaled model and the one is set up with ventilation system another was not. the volume of classroom is 170.1m3 and the number of persons are 35. 1)when the ventilation system was not installed, The experimental results of the $CO_2$ concentration showed the average of 2,150ppm and the maximum of 2,740ppm in the classroom. This was the higher than 1,000ppm, the standard value of ASHRAE and the enforcement regulations of School Sanitation Code in Ministry of Education & Human Resources Development, 1000ppm. The $CO_2$ concentration was relatively increasing during school hours. 3)In case of the volume of ventilation of $800m^3$/h, the $CO_2$ concentration of classroom showed the average of 962 ppm and the maximum of 1,380 ppm. This was higher than 1,000ppm, the standard of ASHRAE and the enforcement regulations of School Sanitation Code in Ministry of Education & Human Resources Development. 4)The floating dust(PM10) was the maximum of 0.52 mg/$m^3$, the minimum of 0.25 mg/$m^3$, and the average of 0.32 mg/$m^3$ in case of the ventilation system off. Those were higher than the standard value 0.15 mg/$m^3$. In case of the ventilation system on, the floating dust(PM10) was the maximum of 0.174 mg/$m^3$ , the minimum of 0.048 mg/$m^3$, and the average of 0.078 mg/$m^3$. These were the lower than 0.15 mg/$m^3$, the standard of the enforcement regulations of School Sanitation Code in Ministry of Education & Human Resources Development. 5)The concentrations of $CO_2$ and PM10 were largely depending on the number of students and the ventilation system, The installation of the ventilation system is necessary for the amenity environment and the management of the indoor air quality.

• Journal of the Korean housing association
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• v.18 no.2
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• pp.21-27
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• 2007

Various buildings constructed by environmentally friendly resources are being built in KOREA. Especially as the wood has distinctive ecological merits in comparison with reinforced concrete and brick, the buildings made by the wood are acknowledged with its superiority of ecological value. Enough field studies for their thermal environment, however, haven't been done. In this study, to investigate indoor environmental condition and occupants' response to it of Log Cabin in Gyeongsangnam-do Hamyang Country Jirisan Natural Recreation Forest, examination of indoor thermal environment and field subjective evaluation have been done in that fundamental information of thermal environment characteristics can be suggested. The results are following; 1) Thermal environment of the Log Cabins; Indoor and outdoor mean dry bulb temperature were $21.9^{\circ}C$ and $-3.1^{\circ}C$, and Indoor and outdoor average relative humidity were 25.8% and 52.1%. These results are below ASHRAE; dry bulb temp. $22.0^{\circ}C$, humidity 30%, and above domestic standards; dry bulb temp. $18{\sim}20.0^{\circ}C$, humidity $40{\sim}60%$. 2) Result of subjective evaluation; Thermal sensation and its comfort were evaluated as 'slightly uncomfortable' because of 'slightly warm'. And humid sensation and its comfort were evaluated as 'slightly uncomfortable' because of 'slightly warm'. 3) Result of vertical temperature and humidity; Vertical temperature difference from head to ankle was $0.54^{\circ}C$ which means most occupants may feel comfortable.