• 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 ${\mu}g/m^3$).

• KIEAE Journal
• /
• v.4 no.3
• /
• pp.203-210
• /
• 2004

This dissertation identifies and investigates the possible control modes of hybrid ventilation system in applying to general apartments. It evaluates range of hybrid ventilation control modes in terms of indoor air quality, thermal comfort, and energy consumption in a living room and a kitchen of the $1000m^2$ apartment. The TRNSYS simulation program was used for evaluating the following four ventilation types : A ventilation mode relying on only infiltration for supplying air, A natural ventilation mode considering with weather condition, A hybrid ventilation (natural + mechanical ventilation) mode allowing minimum ventilation with no heat exchange, and a hybrid ventilation mode with heat exchange. This study shows the following results. As temperature being controlled by heating cooling equipments, there is without significant difference in thermal performance among ventilation types. Regarding Indoor Air quality, Indoor air contamination level of the hybrid ventilation case consistently keep the lower levels. The hybrid ventilation modes consume more energy by a 49% as compared to the A ventilation mode relying on only infiltration for supplying air. It is caused by the continuous ventilation for keeping good indoor air quality; the increase of energy consumption can be attributable to the increase of the heating energy. Therefore, the heat exchange between indoor and outdoor air is required during heating season in severe weather conditions. During the cooling seasons, Introducing natural ventilation can achieve energy saving by 40 ~ 45%. Thus, it can be an effective strategies for energy saving. Based on these results, a hybrid ventilation system can be suggested as an effective ventilation strategy for archiving high level of indoor air quality, thermal comfort, and energy consumption.

• Journal of the Architectural Institute of Korea Structure & Construction
• /
• v.36 no.5
• /
• pp.187-194
• /
• 2020

This study presents the energy-saving sequential control algorithm to handle indoor CO₂ and PM2.5 for the improvement of the air quality of school classrooms. To solve indoor air quality (IAQ) problems, air cleaning and ventilation systems are mainly used for school classrooms. Although air cleaning is able to collect PM2.5, it is difficult to remove harmful gas substances. The ventilation system is suitable to tackle CO and CO₂, the volume ventilation, however, is relatively small. In this paper, to remove CO₂ and PM2.5, the pollutant balance equation for improving indoor air quality is reviewed. The sequential control algorithm of the ventilation and air cleaning system with four levels of criteria is introduced for the effective removal of pollutants. The proposed sequential control algorithm confirms that indoor CO₂ and PM2.5 can be properly controlled below the standard value. In addition, the sequential operation of air cleaning and ventilation systems has shown significant improvement in IAQ compared to the independent ventilation system operation. Particularly, such systems are efficient when outdoor PM2.5 is high.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.13 no.3
• /
• pp.217-223
• /
• 2001

There exist a number of approaches which can evaluate ventilation and indoor air quality. The measurement and analysis of indoor carbon dioxide concentrations can be useful for evaluating indoor air quality and ventilation. This paper describes a numerical analysis of carbon dioxide concentrations for evaluating indoor air quality and ventilation and the factors the need to be considered in their use. The conditions of this numerical analysis are tow types of positions and inlet velocities of ventilation system in a two-dimensional model of an apartment house. The simulation results could be used as a base data for further analysis for ventilation design of other industrial processes producing a proper ventilation system for a healthier and more comfortable environment in a building.

• Journal of Korean Society for Atmospheric Environment
• /
• v.31 no.4
• /
• pp.385-395
• /
• 2015

This study evaluated indoor environmental characteristics in an office room equipped both with ventilation window system and central cooling system. Fresh air is supplied only by the central cooling system whereas indoor air is discharged outside through both ceiling diffuser and a ventilation window system. Numerical study is conducted by changing the volumetric flow rates of exhaust ports of each system. For estimating the performance of this coupled system, $CO_2$ concentration and Predicted Mean Vote (PMV) were calculated using Computational Fluid Dynamics (CFD) simulation. The more the ceiling diffuser exhausts indoor air, the more the $CO_2$ concentration decreases. However, when the ventilation window system exhausts more indoor air, thermal comfort level gets improved in the office room with cooling system. Therefore, when the ventilation window system is operated, the coupled operation with central cooling system should be considered for enhancing indoor air quality and thermal comfort, together.

• Journal of Environmental Science International
• /
• v.7 no.3
• /
• pp.327-334
• /
• 1998

The oil crisis of the 1970s and the rise in oil prices motivated people to implement energy conservation strategies. Buildings were fitted with additional Insulation and reduced ventilation rates. The reduction of mechanical and natural ventilation rate led to Increases In Indoor pollutant concentrations which result- ed In Increased health risks from Indoor exposure to pollutants. The variable-air-volume /bypass fitration system/VAV/BPFS) is a variation of the conventional VAV systems, The VAV/BPFS is an electronically controlled system that provides costegectlve thermal comfort and acceptable indoor air quality Under controlled conditions In a chamber, a series experiments were performed to compare the ability of a VAV/BPFS to remove Indoor aerosol concentration and to reduce energy consumption no that ability of conventional VAV system. Results show that the VAV/BPFS Increases the effective ventilation rate and removes indoor air pollutant, and maintains acceptable indoor air Quality without sacrificing energy consumption.

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

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.19 no.2
• /
• pp.202-211
• /
• 2007

Ventilation system is being recommended as an effective tool to improve indoor air quality (IAQ) in apartment houses. Recently, in Korea, apartment house suppliers must establish ventilation system in apartment houses in law. In this study, improvement of IAQ by establishing mechanical ventilation system at apartment house was investigated by mockup test. Seven apartment houses were arranged for the test and improvement of IAQ was examined under the various conditions of ventilation rates, ventilator type and duct works. The results of this study show that IAQ in the test houses which were established mechanical ventilation system was improved about from 30% to 40% compared with IAQ in the apartment house which was not established ventilation system. However, there were no apparent concentration differences between the cases of changing ventilation rates, ventilator types and ductworks.

• Journal of Environmental Science International
• /
• v.15 no.10
• /
• pp.913-918
• /
• 2006

Despite the wide distribution of air pollutants, the concentrations of indoor air pollutants may be the dominant risk factor in personal exposure due to the fact that most people spend an average of 80% of their time in enclosed buildings. Researches for improvement of indoor air quality have been developed such as installation of air cleaning device, ventilation system, titanium dioxide$(TiO_2)$ coating and so on. However, it is difficult to evaluate the magnitude of improvement of indoor air quality in field study because indoor air quality can be affected by source generation, outdoor air level, ventilation, decay by reaction, temperature, humidity, mixing condition and so on. In this study, evaluation of reduction of formaldehyde and nitrogen dioxide emission rate in indoor environments by $TiO_2$ coating material was carried out using mass balance model in indoor environment. we proposed the evaluation method of magnitude of improvement in indoor air quality, considering outdoor level and ventilation. Since simple indoor concentration measurements could not properly evaluate the indoor air quality, outdoor level and ventilation should be considered when evaluate the indoor net quality.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.17 no.8
• /
• pp.736-745
• /
• 2005

This study is undertaken to evaluate the relationship between the indoor $CO_2$ concentration and the local mean air-age in the lecture room with the occupants. We conducted the experiments to examine the indoor $CO_2$ concentration and the local mean air-age with respect to the supply airflow of the ventilation system and the discharge angle and air-flow of the system air conditioner. Through the experiments, we found out that indoor $CO_2$ concentrations calculated by the prediction equation of Seidel are about 350 ppm lower than those measured by the experiments. The indoor $CO_2$ concentration is not related with the air-flow and the discharge angle of the system air-conditioner, but with the ventilation airflow. From the numerical calculation, the indoor $CO_2$ concentration is not related with the ventilation effectiveness, but strongly with the local mean air-age. In case of our model, the indoor $CO_2$ concentration is likely to fall within the acceptable air quality when the local mean air-age is averagely predicted under 400 seconds.