Energy analysis of a central domestic hot water heating system equipped with condensing boilers

An experimental study was carried out on a central plant for the heating of domestic hot water for a block of 143 flats and 15 offices. The behaviour of the condensing boilers serving the plant was examined and the energy costs of recirculation and distribution were analysed. Since the losses due to recirculation are of the same order as the useful energy, the influence of the various parameters on the losses has been studied, and some methods of lowering them are proposed.