Dongwoo Yeom

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.

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.

Investigation of physiological differences between immersive virtual environment and indoor environment in a building

In the domain of building science and architectural design, the immersive virtual environment is being commonly adopted due to its convenience and cost-effectiveness, especially for research relevant to occupant behaviour in a building indoor environmental control. The goal of this study is to investigate whether such an immersive virtual environment condition could affect an occupants thermal sensation and physiological response to ambient conditions differently, as compared to a real indoor environment, even though those two thermal conditions are the same or very similar. A series of human subject experiments using 18 participants was conducted in an environmental chamber. While thermal conditions were controlled at 20℃ to 30℃ in each environment, respectively, participants were asked to periodically report their thermal sensations on their body. Their heart rates were also continuously measured. The result of our experiments revealed that overall thermal sensations on the whole and local body areas showed some significant differences between the indoor environment and immersive virtual environment conditions during the same thermal conditions. Also, the heart rate difference between two environmental conditions was statistically significant at every thermal sensation level. These findings support the idea that significant physiological response differences could be affected by the immersive virtual environment condition.

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.

Experimental research on temperature and humidity control performance of hwang-toh finishing

This research analysed the effect of the ecological material yellow soil (hwang-toh) on indoor environments. To accomplish this, two full-scale mock-ups were constructed: one with PVC-foamed wallpaper, which is generally used for indoor finishing, and the other with hwang-toh, which is an ecological material for wall finishing. Comparison and performance evaluations were conducted, and the effects of hwang-toh finishing on an indoor environment were verified. Through this research, it was confirmed that a hwang-toh plaster finish is effective in maintaining the comfort humidity of an indoor environment.