Providing thermal protection when replacing window blocks in historical buildings

The work presents the prerequisites to replace the window units in the historical buildings (primarily increased energy efficiency standards of buildings and significantly changed performance requirements of window units). The analysis of possible replacement options (full/partial) of window units of the historical buildings is done according to their architectural and historical values. A review is made of the existing technological capabilities of modern window systems and translucent filling (double-glazed windows), as well as the most common solutions used in practice. The issue of providing the temperature-humidity conditions of the nodes of adjunctions of the window blocks to the openings of the external walls in the winter operating conditions is considered. For this purpose, a numerical simulation of the temperature fields of the junction points is made for various structural embodiments of window frames. It is established that in the case of a full replacement of window blocks and maintaining the existing structure of external walls (the calculation is made using the example of the most common external wall for Central Russia – a brick wall 770 mm thick), condensation may form on the inner surface of window slopes. Different options are suggested for window blocks installation, which ensure the fulfillment of sanitary and hygienic requirements. Further directions for the research on the use of modern types of translucent structures in the historical buildings are outlined.