A condensing heat recovery steam generator (cHRSG) comprising : - a main stack for an exhaust hot gas main flow ; - a bypass stack for allowing a fraction of exhaust hot gas to bypass the exhaust hot gas main flow and to circulate in the bypass stack ; - a primary water circuit and a secondary water circuit ; - a feedwater line fed at a first end with a condensate, and physically connected at a second end to the primary water circuit ; - means for at least partially recovering the latent heat contained inside the fraction of exhaust gas circulating in the bypass stack and for transferring said latent heat to the primary water circuit ; wherein the means for at least partially recovering the latent heat contained inside the fraction of exhaust hot gas circulating in the bypass stack and for transferring said latent heat to the primary water circuit comprise a condensing area ; characterised in that : - the primary water circuit comprises a recirculation loop with a preheater , the latter being located at the entry of the exhaust hot gas main flow in the main stack , and the secondary water circuit is provided with an end-user thermal application , a first heat exchanger being provided for exchanging heat between the primary water circuit and the secondary water circuit , so that the primary water circuit and the secondary water circuit are in thermal contact via the first heat exchanger but are not fluidly interconnected ; and in that - the means for at least partially recovering said latent heat are arranged so as firstly to contribute to a water preheating performed in the preheater of the primary water circuit , and secondly to transfer heat to the end-user thermal application in the secondary water circuit via the first heat exchanger . - a main stack for an exhaust hot gas main flow ; - a bypass stack for allowing a fraction of exhaust hot gas to bypass the exhaust hot gas main flow and to circulate in the bypass stack ; - a primary water circuit and a secondary water circuit ; - a feedwater line fed at a first end with a condensate, and physically connected at a second end to the primary water circuit ; - means for at least partially recovering the latent heat contained inside the fraction of exhaust gas circulating in the bypass stack and for transferring said latent heat to the primary water circuit ; - the primary water circuit comprises a recirculation loop with a preheater , the latter being located at the entry of the exhaust hot gas main flow in the main stack , and the secondary water circuit is provided with an end-user thermal application , a first heat exchanger being provided for exchanging heat between the primary water circuit and the secondary water circuit , so that the primary water circuit and the secondary water circuit are in thermal contact via the first heat exchanger but are not fluidly interconnected ; and in that - the means for at least partially recovering said latent heat are arranged so as firstly to contribute to a water preheating performed in the preheater of the primary water circuit , and secondly to transfer heat to the end-user thermal application in the secondary water circuit via the first heat exchanger . <EOS>