Zbigniew Kowalczyk

This article presents the results of the economic and energy analysis of the operation of five types of windows in residential buildings. The aim of this study was to determine (a) to what extent the construction and various insulation parameters of windows affect the operating costs of buildings, when using different heating systems, (b) to what extent the significant cost of purchasing windows with better insulation is compensated by lower building operation costs (heating and the lifecycle of windows), (c) how the temperature difference inside the building affects heat loss through windows and, as a result, heating costs when using different heating systems. Five types of windows were selected for detailed analysis: a double- and a triple-glazed PVC window, double- and triple-glazed wooden window, and triple-glazed aluminum window. When wooden double-glazed windows are replaced with aluminum windows, the return on investment occurs in just 2 to 4.4 years. It was also found that of the five types of windows tested, the total economic balance of the operation period is the most favorable for PVC windows, regardless of the type of glazing and the heating system. The operating costs of PVC windows in a model residential building are over 30% lower than in the case of wooden windows and almost 20% lower compared to aluminum windows.