An Innovative Device for the Hot Water Circuit in Hospitals to Save Energy Without Compromising the Safety and Quality of Water: Preliminary Results

Legionella colonization of water systems represents a potential hazard for humans within healthcare facilities. It is possible to contain its spread through continuous disinfection systems and the correct management and maintenance of the systems. The hygienic and sanitary quality of the water cannot be ignored in an evaluation of the management and energy costs. The Fondazione Policlinico Universitario A. Gemelli IRCCS in Rome has installed the “ME.SI. MR ACS” (MEthod of SavIngs Maximum eneRgy for hot water) device, which allows the system to activate, when necessary, avoiding continuous water recirculation. The objectives of this study are to evaluate the health and hygiene quality of the hospital water network and to evaluate the thermal and electrical energy savings and chlorine dioxide consumption, with and without this device in operation. This study involved three phases of microbiological sampling in the facility under study: ME.SI. MR ACS device installed but not running, with the boilers’ setpoint temperature at 60 °C; device running with the boilers’ setpoint temperature at 60 °C; and device in operation with the boilers’ setpoint temperature at 45 °C. The microbiological analyses were carried out in accordance with the ISO standard. The data show a constant absence of Legionella spp. in all samples. The application of ME.SI. MR ACS on the hot water recirculation circuit leads to a reduction in the daily consumption of electrical and thermal energy of 68.6% and 48.6%, respectively, for a savings of approximately EUR 23,000/year per circuit. Furthermore, with the device in operation, there is a 50% reduction in the chlorine dioxide consumption with a savings of EUR 11,500/year. ME.SI. MR ACS guarantees thermal and electrical energy savings associated with a reduction in chlorine dioxide consumption, maintaining the hygienic and sanitary quality of the water network.