Kyu-In Lee

Experimental research on the indoor environment control of natural insulation materials: Carbonized rice hull and straw bales

The purpose of this research was to assess the performance of straw bales and carbonized rice hulls when used as natural insulation to regulate the indoor environment. Toward that end, specimens of straw bales and carbonized rice hulls were tested in the Korea Conformity Laboratories. Based on the results, real-scale mockup rooms insulated with these natural materials were constructed for cost analysis and performance evaluation. The cost analysis results showed that carbonized rice hulls are relatively cost effective and economically feasible. The thermal conductivity of carbonized rice hulls is lower than that of straw bales, and no difference in thermal performance was shown in relation to the different construction method used for each material. With regard to humidity, both mockup rooms built with each of the natural materials exhibited stable variations compared to the outside weather, and both materials sustained a general humidity within a comfortable 40–60% range. The straw bales mockup room was shown to produce a higher CO2 emission possibly due to the bio-metabolism (anaerobic fermentation), suggesting that this material should be used with caution. Carbonized rice hulls were proven to be a good natural insulation material and a good regulator of indoor humidity and would not yield CO2 due to bio-metabolism.

Experimental Research on the Correlation of Temperature, Humidity, and CO2 Level of a Rice Hull Insulated Indoor Environment

As quality of life has become a center of attention internationally, studies on comfortable indoor environments have been actively conducted. Particularly, the number of patients suffering from indoor air quality related diseases such as atopic dermatitis and new house syndrome have increased and the average time spent indoors these days is more than half a day, so counter solutions have been attempted in the field of architecture, such as using eco-friendly and ecological materials. With this background, this research aimed to verify the effect of rice hull insulation on the indoor environment, which is widely used in rural areas. To do this, two real-scale mock-ups with rice hull insulation and polystyrene insulated panels, which is the construction generally used in rural areas, were constructed and analyzed, and the effect of rice hull insulation on an indoor environment was verified.

Sustainability Assessment and Development Direction of Super High-rise Residential Complexes from the Viewpoints of Residents

Abstract The study intends to assess the sustainability of super high–rise residential complexes from the viewpoint of residents. For the purpose of this study, the research first reviewed the KGBCC (Korean Green Building Certification Criteria) and related research materials. Secondly, it established sustainability indicators for assessment through synthesis of the KGBCC and UN Habitat Agenda. Finally, the assessment was completed by a survey of the residents of two similar super high–rise residential complexes. The analysis shows that sustainability of super high–rise residential complexes in Korea is low, and the area of ecological environment, energy use and indoor environment must be improved to enhance sustainability. Moreover, the following ten items have to be improved; expansion of interior and exterior green spaces, the establishment of natural habitats, natural ventilation, energy saving, barrier–free planning, the use of environmentally friendly building materials, greening of artificial ground, wind disaster prevention, and expansion of built–in storage spaces.

A Study on Characteristics of Subway Utilization and Pedestrians′ Accessibility at New Towns in Korea

Abstract One of the most important issues in public transportation oriented urban structure is pedestrians′ accessibility to public transportation station. Pedestrians′ accessibility is influenced by socioeconomic conditions such as personal income and location of working places as well as primary factors such as access time and distance. The purpose of this study was to construct a comprehensive transportation selection model using a logistics model in order to understand the influences of various variables on accessibility focusing on subway stations in new towns in metropolitan areas and to set the proper distance for pedestrians. According to the results of the study, we can see that the most influencing factors on the use of subway were possession of vehicles, age, distance and income. It was analyzed that people with annual incomes under 50 million won and who lived in a space smaller than 30 pyung used subway most frequently. Additionally, the threshold distance for walking was 700m primarily and 1,100m secondarily. We can increase subway utilization by walking through dense housing layout in this area.

Study on the Improvement of Korean Green Building Certification Criteria Focused on Certification Score and Specialist Survey Analysis

Abstract The purpose of the research is to suggest improvement directions of G-SEED certification criteria and standards. To verify the present condition and improvement points, the certification scores of 97 apartments were analyzed by category and criteria. Based on this, a certification specialist intensive interview was conducted, and specialist questionnaires were collected for multiple organizations. One hundred and thirty two questionnaires were analyzed by matrix analysis to establish synthetic improvement directions of criteria concerning similar tendencies. Based on this, the final improvement directions of G-SEED criteria were established.

Comparative Research of Residents′ Satisfaction Level Between Green Building-Certified Apartment Complexes and General Apartment Complexes in Korea

Abstract As international considerations concerning the environment increase, various concrete efforts have been attempted, and in response to this, KGBCC (Korean Green Building Certification Criteria) was developed and has operated since 2002. The objective of this study is to research residents′ understanding regarding KGBCC and conduct comparative research on residents′ satisfaction level and the cause of dissatisfaction concerning KGBCC assessment standards, based on KGBCC-certified apartment complex and general apartment complex. For the research, a questionnaire regarding the awareness of the KGBCC, satisfaction level, and cause of dissatisfaction were conducted with residents of a KGBCC-certified apartment complex and a general apartment complex in the Samsan district, Incheon. The survey results were compared and analyzed, and improvements to the KGBCC are suggested.

Study on the indoor environmental performance of complex insulation material: Carbonized rice hull and glass wool

The purpose of this study is to make a complex insulation material with carbonized rice hull and glass wool and to verify the environmental control performance. Full-scale experimental mock-ups were constructed, and the control performance in an indoor environment was compared and verified through monitoring experiments. The complex insulation mock-up showed a relatively high temperature during spring, summer and autumn. The difference in the heat storage capacity of the materials was the cause for this difference. Also, the complex insulation material was proven as more effective at maintaining the stability of the indoor environment and temperature during spring, summer and autumn. In addition, the complex insulation was able to control the indoor humidity at a comfortable level during every season. Our results have therefore verified that the carbonized rice hull was effective at controlling the indoor humidity. When compared with the pure carbonized rice hull insulation, the complex insulation wall was relatively thin; therefore, more net indoor area could be achieved by using the complex insulation material. In addition, if self-produced, the complex insulation could be economically more feasible. Therefore, this complex material was synthetically proven to have merits for insulation of lightweight timber houses for thermal comfort of occupants.

A Study on the Environmental Sustainability Assessment of Multi-Family Housing Estates in Korea

The objective of the present study is to assess the environmental sustainability of multi-family estates in Korea, and based on the assessment, to consider the best future direction for the further promotion of environmental sustainability. In this study, 111 representative multi-family housing estates in Korea were selected and assessed for their sustainability, based on sustainability indicators and standards, and the following conclusions were drawn. In assessment by sectors, the sustainability of landuse and transportation appeared high, but the sustainability of energy and resource use was assessed to be quite low. Indicators such as sunlight use, heavy water use, construction waste recycling and biotop development showed achievement as low as 10%. Thus, these areas will require further efforts. In assessment by estates, the sustainability of landuse appeared high in estates of large-scaled systematic development, but low in those of disordered development or redevelopment. Therefore, the promotion of large-scaled systematic development is recommended. Estates developed under the slogan of environmental-friendliness were found to be superior in both ecological environment and indoor environment, so they should be promoted as well. In addition, estates constructed in the turnkey system attained good marks in several sustainability indicators including energy, which suggests that the turnkey system has advantages.

Experimental Research on the Indoor Environment Performance of Complex Natural Insulation Material: Carbonized Rice Hull and Rice Hull

This study investigated whether the combined use of rice hull and carbonized rice hull (CRH) can offset the negative aspects of each other, and can deliver an optimum indoor environment performance. To achieve this goal, the CO2 emissions of rice hull and the economic feasibility of CRH were considered simultaneously to deliver a mix ratio, and the fundamental properties of the material were analyzed to verify its performance. Full-scale mockups were constructed, and the effect on the indoor environment was verified through monitoring and a comparative analysis. Analysis showed that the heat capacity of the experimental mockup was larger than that of the control, and therefore it was effective in controlling indoor temperature in winter. The application of complex insulation material is also effective in controlling indoor humidity in winter and spring, and a humidity control plan that follows either a moisture-proof plan or ventilation is required to control humidity in summer and autumn. The CO2 level of the experimental mockup was high due to the anaerobic fermentation of the rice hull in the complex material. Therefore, a moisture prevention plan using water-proof and moisture-proof materials and a ventilation plan need to be considered in advance.

Experimental Research on the Temperature and Humidity Control Performance of Cellulose

The purpose of this study is to verify the effect of cellulose insulation on the indoor temperature and humidity. To do so, two full scale mock-ups were constructed which insulated with cellulose and mineral wool, and monitoring data from winter to spring were compared and analyzed. The results showed that temperature variation of both mock-ups appeared stable compared to the outside, and cellulose showed relatively high temperature compared to the mineral wool mock-up due to the good heat storage capacity. In addition, both mock-ups showed stable humidity variation compared to the outdoor, however, humidity of cellulose mock-up stayed in the comfort zone while mineral wool showed higher humidity than comfort level. Therefore, it was proved that cellulose was effective for controlling indoor humidity environment.