Reconstruction of the heating system as an element of thermal modernization of old multi-story residential buildings

The least efficient link in the "heat generation – heat networks – consumer" chain is the consumer, namely the residential sector, where external building envelopes and outdated heating systems are the primary contributors to excessive heat losses.The implementation of apartment-level metering and individual temperature control is not feasible without the recon-struction of existing vertical one-pipe heating systems. New technical solutions are required to preserve energy resources.The system analysis revealed a number of underexplored areas that require further research. Therefore, the comprehen-sive reconstruction of in-building heating systems remains a complex and multifaceted issue, characterized by numerous knowledge gaps.The purpose of this study was to substantiate feasibility of improving the efficiency of heat supply in existing residential buildings by reconstructing their heating systems.The study examines a new method for reconstructing the heating system of the multi-story residential building. Its imple-mentation demonstrated that this approach is technically efficient, economically justified, and energetically feasible.In addition, scientific novelty lies in the proposed methodology for carrying out construction and installation works during reconstruction of heating systems, which can be applied in restoring damaged or outdated infrastructure in multi-story residential buildings.The comparative techno-economic analysis was conducted, revealing that complete replacement of existing vertical one-pipe systems with two-pipe horizontal apartment-based systems, including installation of individual heat meters and tempera-ture control in each apartment is the most appropriate solution.Achieving high levels of energy savings is possible only if comprehensive thermal modernization of residential buildings is carried out in parallel with complete replacement of existing vertical one-pipe heating systems.