The overall objective of the project is to increase energy efficiency by modernising the heat transmission and distribution system. The increase in energy efficiency is achieved by reducing losses in the heat transmission and distribution system. Carrying out the rehabilitation/upgrading of transmission and distribution pipelines results in the reduction of losses in the transmission and distribution network by 109,503 TJ(total losses=26.172 Gkal, 1Gcal=0.004184 TJ; 26.172x0,004184 = 109.503 TJ), representing a 3.85 % reduction in 2019 after completion of rehabilitation works compared to 2015. The project was framed under the Large Infrastructure Operational Programme (POIM), as a result of the fact that thermal networks have high heat losses (over 45 %), so the energy efficiency is low, and the sources (IMA or non-IMA) that produce electricity and heat and which are part of the centralised heat supply system in the Municipality of Iași are major sources of pollution. Phase II of the project aims to increase the energy efficiency of the centralised heat supply system in the Municipality of Iași and to optimise the operation of the entire SACET assembly.