| 요약2 |
The purpose of this study was to calculate U-values and compare quantitative difference based on the assessment methods and input criteria using domestic and international test method to confirm the feasibility of the simulation test of domestic window?set U-values. To that end, the standards of the tests of U-values of domestic and international window sets were discussed and a variety of cases where window set configuration parameters (glass, cavity gas and thickness, frames, spacers, windows sizes) have been changed were simulated using WINDOW&THERM to calculate U-values. The results of U-value Differences against domestic standards by window set portion (glazing, frame, edge) found that differences of NFRC were high in the order of edge>glazing> frame in all the standards. The analysis of U-values by changing the cavity gas and thickness of the window glass having a great impact on a total of U-values in window revealed that differences were high in the order of Krypton > Argon > Air, leading to higher differences of NFRC, compared to those of NFRC. This is explained by the fact that even though convective heat transfer coefficient calculation is the same, the difference of volume expansion coefficient(β) and temperature of the Rayleigh’s number(Ra) formula increases as the difference between indoor and outdoor temperatures of NFRC is 19°C or higher. In addition, an inflection point appeared, where the difference rapidly increases in certain thickness, regardless of types and standards of the cavity gas. It may have been caused by the threshold where convection is activated influenced by cube(d3). The above study attempted to analyze the trends and causes of segmental U-values according to a window set simulation. Additionally, further research will be carried out on various types of window sets in future. |