Evaluating the Effectiveness of Energy-Saving Retrofit Strategies for Residential Buildings

Abstract

Most of the apartment buildings in the Republic of Kazakhstan were built more than 40 years ago. The buildings were designed according to traditional approaches and are the main consumers of thermal energy. The work aims to study various energy-efficient options for modernizing residential buildings and to quantify the actual energy savings and payback period. The paper presents the results of monitoring the energy efficiency of apartment buildings for the period before and after repairs. The results of assessing five thermo-modernization options showed that mineral wool insulation (more than 0.15 m thick) of external walls and roofs saves more than 30 Gcal/year of heat energy. Installation of double-glazed windows with insulating vinyl frame and insulating front doors saves up to 3 Gcal/year of heat energy. It was found that heat recovery ventilation with good thermal tightness of a building can reduce the consumed heat up to 21 Gcal/year. According to the results of the energy audit of the studied buildings, the best modernization options (which increase buildings' energy efficiency 3 times) were selected. A comparative analysis of calculated and actual data on Energy Consumption (EC) after buildings' renovation showed a difference of 10%. The most effective and economical method of apartment buildings' modernization with heat energy consumption of about 0.05 Gcal/m² per year was determined. The results obtained can be used in the passport of buildings and for future research in the field of housing architecture modernization.