Energy usage and cost analysis of passive thermal retrofits for low-rise residential buildings in Seoul

Abstract This study focuses on the energy performance of low-rise residential buildings and on the technological improvements required to improve their performance. As most low-rise residential buildings in Korea are old, they are being renovated to improve their energy efficiency. However, as renovations are expensive, the government intends to apply low-cost energy-efficient technologies that are currently in use as well as quantify their performances. To this end, low-rise residential buildings in villages were selected for the survey; among these, five buildings were evaluated for the application of energy-efficient technologies. Based on the survey, which included information on the actual energy consumption, the reliability of the simulation analysis was verified, and the effects of the technologies were evaluated. The survey focused, in particular, on the airtight performance of the implemented technologies, the efficiency of the heating equipment, and the insulation performance. Moreover, the performances were validated quantitatively by actual measurements. As a result, the energy saving for each technology were evaluated, and the corresponding annual savings were calculated. Finally, the payback period of the investment was evaluated using economic analysis.