• KIEAE Journal
• /
• v.5 no.3
• /
• pp.41-48
• /
• 2005

Before occupation of an apartment housing, the builders are required to inform the test result of IAQ to the public. However, there is no simplified method to predict IAQ before measurement of pollutant concentration. In this study, a simplified way of predicting IAQ based on the distribution of indoor pollutant concentration is proposed. 7 different cases of air change rate have been simulated through CFD analysis to get the distribution ratio of each pollutant material and then simplified functions were used with CRIAQ1 values derived from CFD simulation to evaluate by comparing the influence of each material in the indoor pollutant concentration. Again, a lot of efforts which can improve the indoor air quality have been performed. Materials used in indoor space are labeled with their pollutant emission level. Installation of ventilation system in residential buildings will be regulated by a building codes sooner or later. But it is important to understand the fact that layout of walls, location or size of openings will influence the indoor air flow and pollutant concentration. And location of emitting material influences to indoor air pollutants distribution. But until now there is few recognition and consideration of these factors. Therefore, in this paper the effects of these factors is proved and some kind of guideline is made for designers after a comparison of typical apartment floor plan and a new type plan with their average pollutant concentration and its distribution of each room. CFD(Computational Fluid Dynamics) program was used to show the indoor air flow and pollutant concentration distribution. For this purpose, a typical $100m^2$ apartment floor plan was chosen as a case study model and several alternatives were reviewed to improve the IAQ performance. The simulation took place in the condition of natural ventilation through windows.

• Journal of environmental and Sanitary engineering
• /
• v.15 no.4
• /
• pp.1-3
• /
• 2000

Indoor carbon monoxide (CO) concentration and personal CO exposures were measured Asan where CO poisoning from twenty coal usage briquette as a domestic fuel to cook and space heating. Twenty-five were houses selected from the Asan area for the survey conducted in February 1997. Newly developed passive CO samplers were placed in the kitchen and living room for the indoor concentration measurement and were worn by homemakers for personal exposure monitoring. The daily average of indoor CO concentration was 16ppm in the kitchen and 10ppm in the living room. The indoor concentration and personal exposures to CO were different in types of the space heating system. House ventilating methods and socioeconomic conditions were also important factors in determining the indoor and personal CO level in Asan.

• Journal of Environmental Health Sciences
• /
• v.33 no.5
• /
• pp.372-378
• /
• 2007

This study evaluated formaldehyde concentration in classrooms and on roofs at 4 elementary schools, 3 middle schools and 3 high schools in Incheon City. These schools were chosen based on their surrounding environments that included industrial site, landfill, railway, 8-lane road and harbor. Indoor concentration ranged between 4.65 and $56.25{\mu}g/m^3$, while that of outdoor concentration was $1.23{\sim}10.22{\mu}g/m^3$, both of which were below $100{\mu}g/m^3$, a formaldehyde criterion stipulated by the School Health Act. Indoor concentration was higher than outdoor concentration by $1.4{\sim}5.9$ times, and there was a positive correlation between indoor and outdoor formaldehyde concentrations (R=0.49). As for indoor concentration, multi-use practice rooms had an average 2.8 times higher than that of usual classrooms with a statistically significant difference (p<0.01). Indoor formaldehyde concentration had a positive correlation with the construction year (R=0.55). The school close to the industrial complex had the highest ambient formaldehyde concentration, followed by the one near a landfill. The formaldehyde concentration in school in the vicinity of the industrial complex was twice or more than that of the school located other site. In conclusion, this study suggests that it is crucial to consider surrounding environments in selecting school sites, as it can influence ambient air contamination, as well as using construction material that emit less formaldehyde, in order to protect the health of students, teachers and school staff.

• Journal of Environmental Science International
• /
• v.19 no.2
• /
• pp.125-136
• /
• 2010

The most important factors relating to the indoor air environment are temperature, airflow, humidity, and contaminant concentration. A sensitivity analysis of indoor environment factors was carried out to grasp influences along with changes of atmospheric conditions. An integrated multizone model was used to predict these sensitivities. This model was applied to an apartment with six zones. Airflow rates are influenced very seriously by changes of wind direct or wind velocity, but are influenced very slightly by changes of outdoor air temperature and are not influenced at all by changes of outdoor air humidity or contaminant concentration. Indoor air temperatures are influenced very directly by changes of outdoor air temperature, but are influenced very slightly by wind direction or wind velocity and are not influenced at all by changes of outdoor air humidity or contaminant concentration. Indoor air humidities are influenced very directly by changes of outdoor air humidity, but are not influenced at all by changes of outdoor air contaminant concentration and have little or no influence by changes of wind direction, wind velocity, or outdoor air temperature. Indoor air contaminant concentrations are influenced very seriously by changes of wind direct or wind velocity, but are influenced somewhat by changes of outdoor air contaminant concentration and are influenced very slightly by changes of outdoor air temperature and are not influenced at all by changes of outdoor air humidity.

• International Journal of Air-Conditioning and Refrigeration
• /
• v.13 no.2
• /
• pp.89-98
• /
• 2005

In this study, indoor VOCs concentration emitted from floor and furniture was measured after the installation of floor and furniture in a real residence. With the measured data, prediction method and predication equations for indoor concentration of each VOCs and BTEX were developed. The following conclusions were drawn from this study. First, according to the predicted results of concentration decrease of BTEX (benzene, toluene, ethylbenzene, m,p,o-xylene) after the installation of floor in a real residence, prediction equation can be expressed using exponential function. Second, in case of floor, more reliable prediction equation can be obtained by using cumulative value of indoor concentration than by using just hourly measured value directly. Indoor concentration of benzene can be expressed as $y=408.52(1­e^{-00031{\times}time})$ with $R^2$ of 0.94 which is significantly high value. Third, toluene showed the highest concentration in case of furniture installation indoors, and it needed the longest time for concentration decrease. However, other substances except toluene showed constant concentration throughout the measurement period. Fourth, in case of furniture installation indoors, prediction equation of toluene concentration decrease is estimated to be $y= 3616.3{\times}e^{(-0.1091{\times}time)}+513.96{\times}e^{(-0.0006{\times}time)}\;with\; R^2$ of 0.95 which is significantly high value.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.20 no.4
• /
• pp.241-247
• /
• 2010

Recently, indoor air quality (IAQ) has been one of the major concerns of people. Indoor parking lots are subject to be exposed to high concentrations of air pollutants emitted from vehicles. This study was performed to investigate indoor air quality (IAQ) at indoor parking lots. Sampling sites were selected 5 indoor parking lots. Target indoor air quality parameters include a number of criteria pollutants such PM$_{10}$, CO, CO$_2$, and HCHO. In addition, a variation of IAQ according to ventilation system operating was measured at C site (underground parking lot). In general, all pollutants were maintained below indoor air quality maintenance standards. The indoor air quality at indoor parking lots was affected by the availability of the ventilation facility and their operation frequency. At the underground parking lot (C site) with ventilation system, TVOC concentration according to ventilation system operating were found to be lower operating (488.2 ${\mu}g/m^3$) than non-operating (1,401.2 ${\mu}g/m^3$).

• Journal of Environmental Health Sciences
• /
• v.32 no.4 s.91
• /
• pp.292-303
• /
• 2006

The Volatile Organic Compounds(VOCs) are emitted from various sources and have lots of different form. Recently human are spending the many times at indoor area and indoor air pollution is issued the important social problem. The emission sources of indoor air pollutants are very various, also indoor building materials are composed of very complex chemical compounds, these indoor building materials discharge very much VOCs and other hazardous compounds. In this study, we performed the small chamber test to investigate the VOCs emission concentration and characteristics involving five kinds of the indoor building materials(furniture material, wooden floor, wall paper, paint and tile) under different conditions of four temperature and relative humidity as account of the air flow rate(AFR), air exchange rate(AER), loading factor and air velocity respectively. As the result, It was showed that building materials are emitted the highest VOCs concentration at the beginning of experiment and furniture material is emitted the highest VOCs concentration. Most of the materials were affected by temperature, but paint and tile material were affected by humidity.

• Journal of Radiation Protection and Research
• /
• v.32 no.3
• /
• pp.97-104
• /
• 2007

The corelation between the indoor volume and the measured radon concentration has been analyzed by comparing the radon concentration and the indoor volume of apartment rooms in Jeonju City. We also measured the annual exposure dose based on the variation in indoor radon concentration over time. To do this, we took 8 larger rooms and 8 smaller rooms of apartment, respectively, as a sample. The average volume of the larger rooms and that of the smaller rooms were $31.59\;m^3$ and $16.82\;m^3$, respectively. The average radon concentration of the larger rooms and that of the smaller rooms turned out to be $71.73\;Bq/m^3$ and $108.51\;Eq/m^3$, respectively. indicating that indoor volume is in inverse proportion to the radon concentration, i.e., the bigger the ratio of the surface area/volume, the higher the indoor radon concentration. From the measurement of the variation in indoor radon concentration over time fur a single day, the average intraday radon concentration variation was found to be about $46.8\;Bq/m^3$. The highest level of concentration ($114.5\;Bq/m^3$) was measured between 8 and 10 AM and the lowest level of concentration ($67.7\;Bq/m^3$) between 2 and 4 PM. The annual exposure dose turned out to be in the range of 0.3 mSv/yr to 2.16 mSv/yr, showing that the dose in some apartments exceeded 1.3 mSv/yr, the numerical value presented by the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR).

• Journal of Environmental Health Sciences
• /
• v.45 no.6
• /
• pp.658-667
• /
• 2019

Objective: This study was designed to compare construction types and seasonal radon concentrations in dwellings in Jeollabuk-do Province in Korea. Methods: The measurement of indoor radon concentrations in 79 dwellings using alpha-track detectors was performed every three months (seasonally) over one year between 2015 and 2016. Also, Radon concentrations in soil were measured in spring to investigate the correlations between the concentrations in soil and indoor air. Results: The annual average concentration of indoor radon for dwellings was 89.7±72.1(GM: 72.4) Bq/㎥, with a range (min-max) of 17.2 to 505.4 Bq/㎥. The highest indoor radon concentration was measured in winter and the lowest was shown in summer. The geometric mean of radon concentration in winter was 1.03-2.58 times higher than other seasons. Radon concentrations in soil were investigated at the depth of 1 m, and the concentrations ranged from 1,780 Bq/㎥ to 123,264 Bq/㎥. This showed low correlations with indoor radon concentrations.

• Journal of radiological science and technology
• /
• v.24 no.1
• /
• pp.55-59
• /
• 2001

This study was conducted to find out the radon concentration of indoor air on second floor of a building in Seoul, from January to December in 2000. The following results were achieved ; 1. The annual radon concentration of indoor air was $0.81{\pm}0.35\;pCi/L$ on the average. 2. The time of the highest radon concentration of indoor air was 9 : 00 AM. 3. The radon concentration of indoor air in the year 2000 compared with that in the year 1998 was increased.