• 한국전산유체공학회:학술대회논문집
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• 2003.10a
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• pp.207-208
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• 2003

Increasing interest in indoor air quality (IAQ) control has been found because of its serious effect on human health. To evaluate IAQ, thermal comfort in terms of temperature and velocity distributions of indoor air has to be analyzed in detail. Choice of location for installation of air-conditioner in a building will affect the performance of cooling effect and thermal comfort on the occupants, which in turn will affect the indoor air quality (IAQ) of the building. In this paper, we present a discussion on the proper location of the air-conditioner in order to obtain good thermal comfort for occupant of a typical bedroom in Macao. A set of carefully designed numerical experiments is run with the Computational Fluid Dynamics (CFD) software FLOVENT 3.2 [1]. Reynolds averaged Navier-Stokes equations are solved with finite volume technique and turbulence effects upon the mean flow characteristics is modeled with the k - & model. Assumption of steady state environment is made and only convective and conductive heat transfer from the occupant and air-conditioner are being concerned.

• KIEAE Journal
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• v.8 no.4
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• pp.3-9
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• 2008

The rapid urbanization after 1970s caused the shortage of dwellings in urban areas. As the result, the underground dwellings were developed to compensate for the insufficient dwelling spaces. While the underground dwellings have some advantage in the respect of thermal and acoustic environment, they usually have the basic problems in the indoor air quality because of the lack of natural ventilation through small window areas. The purpose of this study is to investigate and to improve the indoor air quality of underground dwellings. Thirty Units in Seoul and Gyung-Gi Province were investigated into the indoor environmental conditions. For the purpose of the improvement of their indoor air quality, Automatically-operated ventilating fan was installed in a sample unit which has worst indoor environmental condition. Then the indoor air quality was monitored when it was operated by $CO_2$ control system and timer. Finally economic feasibility study was made considering the effect of the improvement of indoor air quality. The extra cost for installing timer could be paid back only in 10 months, so timer-installed automatic fan is recommended to improve the indoor air quality of underground dwellings.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2006.11a
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• pp.143-146
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• 2006

There has been growing concern regarding IAQ(Indoor Air Quality) recently, and IAQ problems from the air-tightness and use of chemical materials addition to the building materials have become increasingly important factors in the built environment. Ventilation is supposed as the solution of healthy indoor quality, and Korea government requests that all new apartment buildings must have a ventilation system as a matter of duty since January, 2006. The purpose of this study is to investigate the indoor concentration change of VOCs include the Formaldehyde according to many different ventilation supply types. Results showed that the reduction effect of target pollutants by the ventilation system was very slight. The cause of these results was attribute to increase the emission rate of building materials by increasing the ventilation rate.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.33 no.12
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• pp.81-90
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• 2017

This study was conducted to investigate the thermal environment status of nursery rooms in workplace daycare centers in Jeju and propose measures to improve their indoor physical thermal environment. For this purpose, measurements were performed in the winter indoor physical environment of 51 nursery rooms in 11 workplace daycare centers and a psychological evaluation survey on the thermal environment of nursery rooms was conducted for 70 nursery teachers. The investigation was carried out over 11 days in January 2017. The results are as follow. The average indoor temperature of the nursery rooms was $21.3^{\circ}C$($18.7-23.8^{\circ}C$) and the indoor temperatures of 47 nursery rooms (92.9%) were higher than the environmental hygiene management standard for domestic school facilities ($18-20^{\circ}C$). The average relative humidity was 33.9% (16.4-56.0%), and 37 nursery rooms (86.3%) showed a lower average relative humidity than the standard (40-70%). The average absolute humidity was $9.1g/m^3$ ($4.7-13.6g/m^3$), which was lower than the standard for preventing influenza ($10g/m^3$). When the indoor temperature and humidity of the nursery rooms were compared with international standards, it was found that 85% or more of the 51 nursery rooms maintained appropriate indoor temperatures, but 40-50% of the nursery rooms maintained a low humidity condition. Therefore, they need to pay attention to maintaining the appropriate humidity of the nursery room to keep the children healthy. The average indoor temperature of the nursery rooms showed a weak negative correlation with the average relative humidity. The indoor temperature had a significant effect on the relative humidity: a higher indoor temperature resulted in lower relative humidity. Regarding the fluctuations in the average indoor temperature of the nursery rooms during the day, in daycare centers that used floor heating, the indoor temperature gradually increased form the morning to the afternoon and tended to decrease during lunch time and the morning and afternoon snack times, due to ventilation. The daycare centers that used both floor heating and ceiling-type air conditioners showed a higher indoor temperature and greater fluctuations in temperature compared to the daycare centers that used floor heating only. In the survey results, the average value of the whole body thermal sensation was 3.0 (neutral): 32 respondents (62.7%) answered, "Neutral", Which was the largest number, followed by 21 respondents (30%) who answered, "Slightly hot" and 17 respondents (24.2%) who answered, "Slightly cold." Twenty-nine respondents answered, "Slightly dry," which was the largest number, followed by 28 respondents (54.9%) who answered, "Neutral" and 10 respondents (19.6%) who answered, "Dry." The total number of respondents who answered, "Slightly dry" or "Dry" was large at 39 (56.4%), which suggests the need for indoor environment management to prevent a low-humidity environment. To summarize the above results about the thermal environment of nursery rooms, as the indoor temperature increased, the relative humidity decreased. This suggests the effect of room temperature on the indoor relative humidity; however, frequent ventilations also greatly decrease the relative humidity. Therefore, the ventilation method and the usage of air conditioning systems need to be re-examined.

• Journal of the Korean housing association
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• v.21 no.2
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• pp.41-48
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• 2010

This study shows how the water space outside the housing impacts the indoor thermal environment. CFD simulation was used for this experiment to analyze the interior environment focusing on the effect of temperature control and the thermal comfort. A shape of perfect square, which creates the very basic space formation, was used and the simulation was processed looking at the size, distance, and the location of the water space. The results of the experiment are as follows. Firstly, introducing a water space with the same floor area size of the simulation model decreased the indoor temperature by 1 Celsius (3.72%). It was determined the interior environment was considered as a comfort zone when the water space was greater than 70% of the floor area. Secondly, there was not much influence to the level of thermal comfort of the interior environment when the distance to the water space from the housing was greater than 2 meters. Lastly, interpreting the location of water space, the effect of controlling the total areas' temperature was the greatest following with the surrounding of the formation. There barely was any change to the temperature considering the side and the rear of the area.

• Journal of Korean Society for Atmospheric Environment
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• v.30 no.3
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• pp.245-250
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• 2014

As the number of nursery facilities and infants who stay there is continuously increasing, IAQ (Indoor Air Quality) of nursery facilities should be managed strictly and thoroughly because infants are more susceptible to infections due to their low resistivity. In this study the characteristics of IAQ and ventilation associated factors were investigaed for suggesting a desirable condition for IAQ management. Environmental factors were not much related to IAQ characteristics rather than internal factors such as structures of the room. And the positive effect of ventilation on IAQ was obvious and seemed to hinge on factors related to window area especially window/wall ratio. Results of this study indicate that the structure with broader window area of a room and frequnet ventilation can be an effective way for keeping IAQ of nursery facilities clean and safe.

• KIEAE Journal
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• v.7 no.6
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• pp.3-8
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• 2007

Recently, because of the continuous rise of international oil price, energy saving is strongly demanding. So, Ecological technics of architecture such as use of natural energy have been actively explored in the field of building. In the method of utilizing natural energy, the key point is to saving energy effectively as not lowering the comfort of indoor environment, various systems investigated. Many papers about double skin facade system have been reported, it is announced broadly that the system is very effective in improvement of natural ventilation and indoor thermal environment, and also protecting outdoor sound. The shaft box facade is a special form of box window construction. It consists of a system of box windows with continuous vertical shafts that extend over a number of stories to create a stack effect. The facade layout consists of an alternation of box windows and vertical shaft segments. This research investigated the natural ventilation performance of shaft box type balcony which conform the shaft box type double skin to the exiting balcony construction. First, analyzed various types of exiting apartments, proto-type was decided. By using virtual environment Program, modeling the proto-type, compared the contribution of air temperature and the effect of outdoor air cooling. by this research, we confirmed that shaft box type balcony had many possibility for improvement of indoor environment.

• Journal of the Korean Solar Energy Society
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• v.25 no.1
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• pp.45-55
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• 2005

In the summer, the irradiated solar heat gain through the roof has an effect on the thermal environment of the top floor units of apartment houses. This paper investigated the differences of the indoor air temperature, globe temperature and thermal comfort index between the top floor unit and the middle floor unit by measuring them at the sample units on the condition that all the openings of the units are opened. The purpose of this paper is to provide quantitative data about the irradiated solar heat gain during the summertime through the roof of an apartment house and these data to be the source to reevaluate the appropriate roof insulation efficiency. From this study, we obtained three brief results as follows. Indoor air temperature difference between the two sample units shifts a day. Indoor air temperature at the top floor unit is $0{\sim}1.8^{\circ}C$ higher than that of the middle floor unit from 12:00 p.m. to 12:00 a.m. and $0{\sim}2.8^{\circ}C$ lower from 12:00 a.m. to 12:00 p.m. The evaluation of the indoor thermal comfort index and the globe temperature shows similar results as the indoor air temperature measuring. Results of this experiment verified the actual existence of indoor air temperature difference between the top floor unit and the middle one and this difference comes from the heat storage of the roof.

• Journal of the Korean Solar Energy Society
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• v.24 no.4
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• pp.45-53
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• 2004

In the summer, the irradiated solar heat gain through the roof has an effect on the thermal environment of the top floor units of apartment houses. This paper investigated the differences of the indoor air temperature and thermal comfort index between the top floor unit and the middle floor unit by measuring them at the sample houses. The purpose of this paper is to provide quantitative data about the irradiated solar heat gain during the summertime through the roof of an apartment house and these data to be the source to reevaluate the appropriate roof insulation efficiency. From this study, we obtained the brief results as follows. Indoor air temperature at the top floor unit is $1.2\sim2.2^{\circ}C$ higher than that of middle floor unit. The evaluation of the indoor thermal comfort index at each sample rooms reveals notable thermal differences between the two units. Top floor units need more cooling load during the summertime compared to middle floor units. Therefore, solutions to reduce solar Heat gain at top floor units to be considered.

• KIEAE Journal
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• v.13 no.1
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• pp.75-81
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• 2013

The balcony of our apartment building consists of unique construction similar to double skin. It is announced broadly that double skin is very effective system in improvement of natural ventilation and indoor thermal environment, and outdoor sound protection. So, for the improvement of indoor climate and energy saving, many peoples studied about environmental performance of our balcony construction. This study focus on shaft box facade, special form of box window construction. It consists of a system of box window with continuous vertical shafts that extend over a number of stories to create a stack effect. Proto-type was decided by analyzing various types of exiting apartments. Shaft box type balcony was created by setting up shaft space at a part of balcony. Air flow and contribution of air temperature were simulated, performance of shaft box type balcony was compared with existing balcony. Finally, we confirmed that shaft box type balcony has many possibility for improvement of indoor environment.