Dong-Woo Cho

Performance evaluation on cool roofs for green remodeling

Cool roofs refer that maximize heat emission, and minimize the absorption of solar radiation energy, by applying high solar reflectance paints, or materials to roofs or rooftops. The application of cool roofs to existing buildings does not need to take structural issues into consideration, as rooftop greening, is an alternative that can be applied to existing buildings easily. This study installed a cool roofs on existing buildings, and evaluated the performances, using the results to propose certification standards for green remodeling, considering the cool roof-related standards.

A Case Study on Pressurization Method using HVAC System depends on Outdoor Conditions to Reduce Stack Effect in the High-rise Office Building

This study aims to investigate optimized mechanical pressurization of each outdoor air temperature in order to resolve noise problems associated with stack effect. For this study, noise levels resulted by stack effect was measured during three months of winter, and airtight practices and mechanical pressurization practices of each outdoor air condition employed on a high-rise office building under operation. Noise level was measured in the elevator halls located on the lobby floor(1st floor) and the highest floor (47th floor). The average noise level of the 1st floor was 59 dB(A) under all HVAC system-off, exceeding the recommended level 57 dB(A), even after average of 9dB(A) was reduced after airtight practices were employed, After mechanical pressurization practices as pressurized floor in high-rise zone were employed, most noise levels met the recommended niose level 57 dB(A) for 1F elevator lobby and 48 dB(A) for 47F elevator lobby.