Seong Jin Chang

Development of heat storage gypsum board with paraffin-based mixed SSPCM for application to buildings

Abstract Latent heat thermal energy storage using phase change materials (PCMs) is considered to be the method with the most potential to solve the energy shortage problem. In this study, paraffin-based mixed shape-stabilized PCM (SSPCM) (PBMS) was made by vacuum impregnation method. The prepared PBMS was added to gypsum powder as a fine aggregate. In the experiment, the n-hexadecane and n-octadecane was used as the PCM and the materials have latent heat capacities of 254.7 and 247.6 J/g, and melting points of 20.84 and 30.4 °C, respectively. The PBMS was prepared by an impregnation method in a vacuum, following the manufacturing process. The physical and thermal properties of the PBMS gypsum board were analyzed by Fourier transform infrared spectrometry (FTIS), differential scanning calorimetry, enthalpy analysis, and thermogravimetric analysis. From the Fourier transform infrared analysis, PBMS could be maintained in the structure of the gypsum board due to its physical rather than chemical bonding. From the specific heat and enthalpy analysis, the PBMS has high enthalpy and thermal inertia property. In addition, the gypsum board with PBMS has high latent heat capacity and high thermal efficiency.

Analysis of Hygrothermal Performance of Wood Frame Walls according to Position of Insulation and Climate Conditions

The insulation of a building envelope influences the hygrothermal performance as well as the thermal performance of the building. While most of Korean wood frame houses have an interior insulation system, the exterior insulation system with high thermal performance has recently been applied. While it can be effective in energy savings for better insulation performance, without consideration of the moisture, condensation and mould growth can occur. Therefore, in this study, hygrothermal behaviour, water content, and mould growth were analyzed using hygrothermal simulation of an exterior wall of a wood frame house with which the interior insulation and exterior insulation systems were applied. The wall layer included Wall A (Interior insulation) and Wall B (Exterior insulation). The U-values were identified as 0.173 and 0.157 W/m2K, respectively. The total water content and OSB absolute water content of Wall A were confirmed to be higher than those of Wall B, but the absolute water content did not exceed the reference value of 20%. The moisture content of the two walls was determined to be stable in the selected areas. However, mould growth risk analysis confirmed that both Wall A and Wall B were at risk of mould growth. It was confirmed that as the indoor setting temperature decreased, the mould index and growth rate in the same area increased. Therefore, the mould growth risk was affected more by indoor and outdoor climate conditions than by the position of the insulation. Consequently, the thermal performance of Wall B was superior to that of Wall A but the hygrothermal performances were confirmed to be similar.

Evaluation of the Adsorption Performance and Sustainability of Exfoliated Graphite Nanoplatelets (xGnP) for VOCs

Exfoliated graphite nanoplatelets (xGnP), which combine the layered structure and low price of nanoclays with the superior mechanical, electrical, and thermal properties of carbon nanotubes, are very cost-effective, and can simultaneously provide a multitude of physical and chemical property enhancements. In this study, we evaluated xGnP’s adsorption performance of volatile organic compounds (VOCs) according to thermal extractor (TE) analysis for seven days in order to use the xGnP as an adsorption material of pollutants. In addition, we carried out a sustainability evaluation in order to evaluate its adsorption capacity over 28 days. The results indicate that the adsorption performance of xGnP is higher than for other adsorption materials such as zeolite. Also, we determined that the adsorption performance of xGnP is maintained continuously for 28 days and that its adsorption capacity is large.

Evaluation of Toluene Adsorption Performance of Mortar Adhesives Using Porous Carbon Material as Adsorbent

Porous carbon materials are advantageous in adsorbing pollutants due to their wide range of specific surface areas, pore diameter, and pore volume. Among the porous carbon materials in the current study, expanded graphite, xGnP, xGnP C-300, xGnP C-500, and xGnP C-750 were prepared as adsorbent materials. Brunauer–Emmett–Teller (BET) analysis was conducted to select the adsorbent material through the analysis of the specific surface area, pore size, and pore volume of the prepared porous carbon materials. Morphological analysis using SEM was also performed. The xGnP C-500 as adsorbent material was applied to a mortar adhesive that is widely used in the installation of interior building materials. The toluene adsorption performances of the specimens were evaluated using 20 L small chamber. Furthermore, the performance of the mortar adhesive, as indicated by the shear bond strength, length change rate, and water retention rate, was analyzed according to the required test method specified in the Korean standards. It was confirmed that for the mortar adhesives prepared using the xGnP C-500 as adsorbent material, the toluene adsorption performance was excellent and satisfied the required physical properties.

Analysis of Hygrothermal Performance for Standard Wood-frame Structures in Korea

본 연구는 WUFI Pro 5.3을 이용하여 한국농어촌공사에서 제시하고 있는 농어촌 표준 목조주택 설계를 기준으로 목조 벽체의 hygrothermal 거동에 대한 평가를 실시하였다. 그 결과, 2010년도에 제시된 벽체보다 2014년도에 개선된 벽체의 Total Water Contents (TWC)가 더 낮게 나타난 것을 확인하였고, 3년간의 평가에서 T...