Warm water systems, losses and Legionella

A study by the Swedish Energy Agency shows that domestic hot water systems in apartment buildings account for 27–81 kWh/m² per year, divided between water heating and distribution losses. The warm water circulation system's energy losses amount to 10-17 kWh/m². For Sweden's 205 million square meters of heated surface in apartment buildings, this corresponds to 2.5 - 4.3 TWh/year. The Housing Agency's standards specify a minimum system temperature of 50˚C to counteract Legionella, which increases heat losses. The project investigates how Legionella grows depending on flow profiles and temperatures, as well as the effects of measures to counteract growth, and maps the energy saving potential.