Windows in new buildings in Korea are equipped with double or triple glazing, a low-E coating, and gas injection between the panes of glass, in accordance with the regulations for the reinforced insulation of windows. However, these windows have certain issues, such as thermal transmittance variations and injected gas leakage. In this study, we investigated the current status of double-glazed windows filled with argon gas and analyzed the actual deterioration degree in terms of insulation performance via field experiments and simulations. Accordingly, we manufactured a 26-millimeter low-E double-glazed window test specimen and conducted tests in accordance with the KS F 2278 standard. The test results indicated that the thermal performance decreased by 10.9% when the argon gas filling rate was reduced from 95% to 0%. The simulation results showed that the thermal performance of windows that were insulated using only glazing decreased by 22.6% with the decrease in the argon gas filling rate; the thermal performance of the double-glazed windows also decreased by 13.6%. A comprehensive analysis of the field surveys and simulations predicted a 92% probability that the argon gas filling rate of double-glazed windows would be below 65% by two years after completion, in addition to a ~4.3% decrease in thermal performance.

In high-rise buildings, the stack effect causes various problems, especially problems related to excessive pressure differences across main entrance doors and elevator doors, particularly in heating seasons. To reduce the stack effect, this study aims to find effective operation schemes for the HVAC systems in a 60-story commercial building, located in Seoul, Korea. Field measurements were conducted to identify the problems related to the stack effect in the building. Computer simulations were conducted to examine the effectiveness of various HVAC operation schemes in reducing the stack effect. Then, an optimum and effective operation scheme was adopted from the computer simulation results and applied in the field. The adopted scheme was used to pressurize the upper zone of the building. Through field application and an adjustment process, a proper amount of air volume was found to effectively pressurize the upper zone of this building, solving the problems related to the stack effect. The required air volume for pressurization was maintained in the building by reducing the volume of the exhaust air (EA) while maintaining a constant volume of outdoor air (OA).

Indoor CO₂ concentration is considered a metric of indoor air quality that affects the health of occupants. In this study, a hybrid model was developed for forecasting the varying indoor CO₂ concentration levels in a residential apartment unit in the presence of occupants by controlling the ventilation rates of a heat recovery ventilator. In this model, the mass balance equation for a single zone as a white-box model was combined with a Bayesian neural network (BNN) as a black box model. During the learning process of the hybrid model, the BNN estimated an aggregated unknown ventilation rate and transferred the estimation to the mass-balance equation. A parametric study was conducted by changing the prediction horizons of the hybrid model from 5 to 15 min, and the forecasting performance of the hybrid model was compared with the stand-alone mass balance equation. The hybrid model showed better forecasting performance than that of the mass balance equation on the experimental dataset for a living room and bedroom. The average MBE and CVRMSE of the hybrid model for the prediction horizon of 15 min were 0.65% and 5.23%, respectively, whereas those of the mass balance equation were 0.99% and 9.30%, respectively.

Double skin facade systems are known to be capable of preventing overheating in curtain wall buildings to a certain degree. The system induces the efficient blocking of sunlight using a center blind during the summer season. Moreover, it enables overheated air in the cavity layer to be sent outdoors, resulting in a reduction of the use of energy for cooling. However, double skin facade systems can be problematic, in that they must be opened according to seasonal conditions to achieve greater energy consumption efficiencies. In current double skin facade systems, the width of the cavity layer was too wide for residents to easily operate the system. When considering this, research on an easy-to-open 270 mm slim-type double skin window (SDSW) was undertaken in order to confirm its energy efficient performance. First, official testing based on the KS L 9107 Standard was undertaken to analyze solar heat gain coefficients (SHGC) and the cavity air temperatures, according to the open and close conditions of the SDSW’s external windows, enabling an analysis of the effect that the opening of windows had on reducing cooling energy needs. Next, SHGCs and cavity air temperatures were studied according to the different opening conditions of the SDSW’s external window to analyze the most optimal effects on cooling energy reductions by Computational Fluid Dynamics (CFD).

A new assessment method for the “Energy Performance” issue in the Green Standard for Energy and Environmental Design (G-SEED) was developed in this study. First, the corresponding issues in green building rating systems in advanced countries were reviewed and analysed, and then a new assessment method that uses dynamic building energy simulation programs was developed. The most important part of the new method was developing guidelines for modelling a reference building using simulation programs. Therefore, details of the simulation inputs for a reference building model were provided, and new guidelines were developed in this study. To evaluate the new assessment method, it was applied to a multi-residential building in Seoul, South Korea, and the results were compared to those from the current assessment method in G-SEED.

G-SEED(Green Standard for Energy and Environmental Design) is operating in Korea as a certification system to evaluate the environmental friendliness of buildings. Buildings are generating loads such as carbon dioxide emission, energy consumption, the consumption of resources, destruction of natural ecosystem, change of global climate, pollution of indoor environment, and waste generation. For this purpose, a green building certification system has been introduced. In the green building certification system, evaluation of buildings through methods such as utilization of natural energy, adoption of energy saving system, rainwater management, etc., is induced to reduce environmental load. These certification systems are operated by each country. The level of the certification system is different according to the characteristics such as climate environment. BREEAM in the UK and LEED in the US are operating a version for international certification as well as domestic certification. In this study, analyze the certification system which operates the global version such as BREEAM, LEED. And to investigate the differences between domestic and international versions of each version of the certification system. Certification items classified as reflected by climate characteristics, national characteristics reflected items, general items, such as attempts to analyze the rating system. And certification items were grouped into general “Global certification items” having no specificity for locality and “Local certification items” that differ by each locality according to social, environmental, and political factors. Using the analysis results that comparison of LEED and BREEAM, the study then aims to ascertain the possibility of whether the G-SEED can be used to certify international buildings. And explore the possibility of developing international version of the G-SEED and indicate the direction of G-SEED amendments that may arise in the future. The study results would be available as basic data at the development of G-SEED for international version.