Flow temperature

Flow temperature is the temperature of the heating water as it leaves a heat source or heating circuit and travels towards heat emitters such as radiators, underfloor heating or fan convectors. In a heat pump system it affects how much heat the emitters can deliver and how efficiently the heat pump can run: MCS guidance explains that lower flow temperatures generally improve heat pump efficiency, while the chosen design temperature still has to meet the room heat losses at the design outdoor condition. The term is not the room thermostat setting, the return temperature, the heat pump kW output or proof that the heating system has been designed correctly.